ar71xx: disable DDR flush for ethernet on AR934x, it is no longer necessary
[openwrt.git] / target / linux / generic / patches-2.6.31 / 270-sched_bfs.patch
1 This patch adds support for bfs v230, modified for diff size reduction
2
3 --- a/Documentation/sysctl/kernel.txt
4 +++ b/Documentation/sysctl/kernel.txt
5 @@ -27,6 +27,7 @@ show up in /proc/sys/kernel:
6 - domainname
7 - hostname
8 - hotplug
9 +- iso_cpu
10 - java-appletviewer [ binfmt_java, obsolete ]
11 - java-interpreter [ binfmt_java, obsolete ]
12 - kstack_depth_to_print [ X86 only ]
13 @@ -49,6 +50,7 @@ show up in /proc/sys/kernel:
14 - randomize_va_space
15 - real-root-dev ==> Documentation/initrd.txt
16 - reboot-cmd [ SPARC only ]
17 +- rr_interval
18 - rtsig-max
19 - rtsig-nr
20 - sem
21 @@ -171,6 +173,16 @@ Default value is "/sbin/hotplug".
22
23 ==============================================================
24
25 +iso_cpu: (BFS only)
26 +
27 +This sets the percentage cpu that the unprivileged SCHED_ISO tasks can
28 +run effectively at realtime priority, averaged over a rolling five
29 +seconds over the -whole- system, meaning all cpus.
30 +
31 +Set to 70 (percent) by default.
32 +
33 +==============================================================
34 +
35 l2cr: (PPC only)
36
37 This flag controls the L2 cache of G3 processor boards. If
38 @@ -333,6 +345,19 @@ rebooting. ???
39
40 ==============================================================
41
42 +rr_interval: (BFS only)
43 +
44 +This is the smallest duration that any cpu process scheduling unit
45 +will run for. Increasing this value can increase throughput of cpu
46 +bound tasks substantially but at the expense of increased latencies
47 +overall. This value is in milliseconds and the default value chosen
48 +depends on the number of cpus available at scheduler initialisation
49 +with a minimum of 6.
50 +
51 +Valid values are from 1-5000.
52 +
53 +==============================================================
54 +
55 rtsig-max & rtsig-nr:
56
57 The file rtsig-max can be used to tune the maximum number
58 --- a/include/linux/init_task.h
59 +++ b/include/linux/init_task.h
60 @@ -116,9 +116,10 @@ extern struct cred init_cred;
61 .usage = ATOMIC_INIT(2), \
62 .flags = PF_KTHREAD, \
63 .lock_depth = -1, \
64 - .prio = MAX_PRIO-20, \
65 + .prio = NORMAL_PRIO, \
66 .static_prio = MAX_PRIO-20, \
67 - .normal_prio = MAX_PRIO-20, \
68 + .normal_prio = NORMAL_PRIO, \
69 + .deadline = 0, \
70 .policy = SCHED_NORMAL, \
71 .cpus_allowed = CPU_MASK_ALL, \
72 .mm = NULL, \
73 --- a/include/linux/sched.h
74 +++ b/include/linux/sched.h
75 @@ -36,9 +36,12 @@
76 #define SCHED_FIFO 1
77 #define SCHED_RR 2
78 #define SCHED_BATCH 3
79 -/* SCHED_ISO: reserved but not implemented yet */
80 +#define SCHED_ISO 4
81 #define SCHED_IDLE 5
82
83 +#define SCHED_MAX (SCHED_IDLE)
84 +#define SCHED_RANGE(policy) ((policy) <= SCHED_MAX)
85 +
86 #ifdef __KERNEL__
87
88 struct sched_param {
89 @@ -1090,10 +1093,13 @@ struct sched_entity {
90 struct load_weight load; /* for load-balancing */
91 struct rb_node run_node;
92 struct list_head group_node;
93 +#ifdef CONFIG_SCHED_CFS
94 unsigned int on_rq;
95
96 u64 exec_start;
97 +#endif
98 u64 sum_exec_runtime;
99 +#ifdef CONFIG_SCHED_CFS
100 u64 vruntime;
101 u64 prev_sum_exec_runtime;
102
103 @@ -1145,6 +1151,7 @@ struct sched_entity {
104 /* rq "owned" by this entity/group: */
105 struct cfs_rq *my_q;
106 #endif
107 +#endif
108 };
109
110 struct sched_rt_entity {
111 @@ -1172,17 +1179,19 @@ struct task_struct {
112
113 int lock_depth; /* BKL lock depth */
114
115 -#ifdef CONFIG_SMP
116 -#ifdef __ARCH_WANT_UNLOCKED_CTXSW
117 int oncpu;
118 -#endif
119 -#endif
120 -
121 int prio, static_prio, normal_prio;
122 unsigned int rt_priority;
123 const struct sched_class *sched_class;
124 struct sched_entity se;
125 struct sched_rt_entity rt;
126 + unsigned long deadline;
127 +#ifdef CONFIG_SCHED_BFS
128 + int load_weight; /* for niceness load balancing purposes */
129 + int first_time_slice;
130 + unsigned long long timestamp, last_ran;
131 + unsigned long utime_pc, stime_pc;
132 +#endif
133
134 #ifdef CONFIG_PREEMPT_NOTIFIERS
135 /* list of struct preempt_notifier: */
136 @@ -1205,6 +1214,9 @@ struct task_struct {
137
138 unsigned int policy;
139 cpumask_t cpus_allowed;
140 +#ifdef CONFIG_HOTPLUG_CPU
141 + cpumask_t unplugged_mask;
142 +#endif
143
144 #ifdef CONFIG_PREEMPT_RCU
145 int rcu_read_lock_nesting;
146 @@ -1497,11 +1509,19 @@ struct task_struct {
147 * priority to a value higher than any user task. Note:
148 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
149 */
150 -
151 +#define PRIO_RANGE (40)
152 #define MAX_USER_RT_PRIO 100
153 #define MAX_RT_PRIO MAX_USER_RT_PRIO
154 -
155 +#ifdef CONFIG_SCHED_BFS
156 +#define MAX_PRIO (MAX_RT_PRIO + PRIO_RANGE)
157 +#define ISO_PRIO (MAX_RT_PRIO)
158 +#define NORMAL_PRIO (MAX_RT_PRIO + 1)
159 +#define IDLE_PRIO (MAX_RT_PRIO + 2)
160 +#define PRIO_LIMIT ((IDLE_PRIO) + 1)
161 +#else
162 #define MAX_PRIO (MAX_RT_PRIO + 40)
163 +#define NORMAL_PRIO (MAX_RT_PRIO - 20)
164 +#endif
165 #define DEFAULT_PRIO (MAX_RT_PRIO + 20)
166
167 static inline int rt_prio(int prio)
168 @@ -1785,7 +1805,7 @@ task_sched_runtime(struct task_struct *t
169 extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
170
171 /* sched_exec is called by processes performing an exec */
172 -#ifdef CONFIG_SMP
173 +#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_CFS)
174 extern void sched_exec(void);
175 #else
176 #define sched_exec() {}
177 --- a/init/Kconfig
178 +++ b/init/Kconfig
179 @@ -451,9 +451,22 @@ config LOG_BUF_SHIFT
180 config HAVE_UNSTABLE_SCHED_CLOCK
181 bool
182
183 +choice
184 + prompt "Scheduler"
185 + default SCHED_CFS
186 +
187 + config SCHED_CFS
188 + bool "CFS"
189 +
190 + config SCHED_BFS
191 + bool "BFS"
192 +
193 +endchoice
194 +
195 config GROUP_SCHED
196 bool "Group CPU scheduler"
197 depends on EXPERIMENTAL
198 + depends on SCHED_CFS
199 default n
200 help
201 This feature lets CPU scheduler recognize task groups and control CPU
202 @@ -504,6 +517,7 @@ endchoice
203
204 menuconfig CGROUPS
205 boolean "Control Group support"
206 + depends on SCHED_CFS
207 help
208 This option adds support for grouping sets of processes together, for
209 use with process control subsystems such as Cpusets, CFS, memory
210 --- a/kernel/Makefile
211 +++ b/kernel/Makefile
212 @@ -2,7 +2,7 @@
213 # Makefile for the linux kernel.
214 #
215
216 -obj-y = sched.o fork.o exec_domain.o panic.o printk.o \
217 +obj-y = $(if $(CONFIG_SCHED_CFS),sched.o,sched_bfs.o) fork.o exec_domain.o panic.o printk.o \
218 cpu.o exit.o itimer.o time.o softirq.o resource.o \
219 sysctl.o capability.o ptrace.o timer.o user.o \
220 signal.o sys.o kmod.o workqueue.o pid.o \
221 @@ -108,6 +108,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER
222 # I turn this off for IA-64 only. Andreas Schwab says it's also needed on m68k
223 # to get a correct value for the wait-channel (WCHAN in ps). --davidm
224 CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer
225 +CFLAGS_sched_bfs.o := $(PROFILING) -fno-omit-frame-pointer
226 endif
227
228 $(obj)/configs.o: $(obj)/config_data.h
229 --- a/kernel/kthread.c
230 +++ b/kernel/kthread.c
231 @@ -16,7 +16,11 @@
232 #include <linux/mutex.h>
233 #include <trace/events/sched.h>
234
235 +#ifdef CONFIG_SCHED_BFS
236 +#define KTHREAD_NICE_LEVEL (0)
237 +#else
238 #define KTHREAD_NICE_LEVEL (-5)
239 +#endif
240
241 static DEFINE_SPINLOCK(kthread_create_lock);
242 static LIST_HEAD(kthread_create_list);
243 --- /dev/null
244 +++ b/kernel/sched_bfs.c
245 @@ -0,0 +1,6105 @@
246 +/*
247 + * kernel/sched_bfs.c, was sched.c
248 + *
249 + * Kernel scheduler and related syscalls
250 + *
251 + * Copyright (C) 1991-2002 Linus Torvalds
252 + *
253 + * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
254 + * make semaphores SMP safe
255 + * 1998-11-19 Implemented schedule_timeout() and related stuff
256 + * by Andrea Arcangeli
257 + * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
258 + * hybrid priority-list and round-robin design with
259 + * an array-switch method of distributing timeslices
260 + * and per-CPU runqueues. Cleanups and useful suggestions
261 + * by Davide Libenzi, preemptible kernel bits by Robert Love.
262 + * 2003-09-03 Interactivity tuning by Con Kolivas.
263 + * 2004-04-02 Scheduler domains code by Nick Piggin
264 + * 2007-04-15 Work begun on replacing all interactivity tuning with a
265 + * fair scheduling design by Con Kolivas.
266 + * 2007-05-05 Load balancing (smp-nice) and other improvements
267 + * by Peter Williams
268 + * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
269 + * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
270 + * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
271 + * Thomas Gleixner, Mike Kravetz
272 + * now Brainfuck deadline scheduling policy by Con Kolivas deletes
273 + * a whole lot of those previous things.
274 + */
275 +
276 +#include <linux/mm.h>
277 +#include <linux/module.h>
278 +#include <linux/nmi.h>
279 +#include <linux/init.h>
280 +#include <asm/uaccess.h>
281 +#include <linux/highmem.h>
282 +#include <linux/smp_lock.h>
283 +#include <asm/mmu_context.h>
284 +#include <linux/interrupt.h>
285 +#include <linux/capability.h>
286 +#include <linux/completion.h>
287 +#include <linux/kernel_stat.h>
288 +#include <linux/debug_locks.h>
289 +#include <linux/perf_counter.h>
290 +#include <linux/security.h>
291 +#include <linux/notifier.h>
292 +#include <linux/profile.h>
293 +#include <linux/freezer.h>
294 +#include <linux/vmalloc.h>
295 +#include <linux/blkdev.h>
296 +#include <linux/delay.h>
297 +#include <linux/smp.h>
298 +#include <linux/threads.h>
299 +#include <linux/timer.h>
300 +#include <linux/rcupdate.h>
301 +#include <linux/cpu.h>
302 +#include <linux/cpuset.h>
303 +#include <linux/cpumask.h>
304 +#include <linux/percpu.h>
305 +#include <linux/kthread.h>
306 +#include <linux/proc_fs.h>
307 +#include <linux/seq_file.h>
308 +#include <linux/syscalls.h>
309 +#include <linux/times.h>
310 +#include <linux/tsacct_kern.h>
311 +#include <linux/kprobes.h>
312 +#include <linux/delayacct.h>
313 +#include <linux/reciprocal_div.h>
314 +#include <linux/log2.h>
315 +#include <linux/bootmem.h>
316 +#include <linux/ftrace.h>
317 +
318 +#include <asm/tlb.h>
319 +#include <asm/unistd.h>
320 +
321 +#define CREATE_TRACE_POINTS
322 +#include <trace/events/sched.h>
323 +
324 +#define rt_prio(prio) unlikely((prio) < MAX_RT_PRIO)
325 +#define rt_task(p) rt_prio((p)->prio)
326 +#define rt_queue(rq) rt_prio((rq)->rq_prio)
327 +#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH))
328 +#define is_rt_policy(policy) ((policy) == SCHED_FIFO || \
329 + (policy) == SCHED_RR)
330 +#define has_rt_policy(p) unlikely(is_rt_policy((p)->policy))
331 +#define idleprio_task(p) unlikely((p)->policy == SCHED_IDLE)
332 +#define iso_task(p) unlikely((p)->policy == SCHED_ISO)
333 +#define iso_queue(rq) unlikely((rq)->rq_policy == SCHED_ISO)
334 +#define ISO_PERIOD ((5 * HZ * num_online_cpus()) + 1)
335 +
336 +/*
337 + * Convert user-nice values [ -20 ... 0 ... 19 ]
338 + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
339 + * and back.
340 + */
341 +#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
342 +#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
343 +#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
344 +
345 +/*
346 + * 'User priority' is the nice value converted to something we
347 + * can work with better when scaling various scheduler parameters,
348 + * it's a [ 0 ... 39 ] range.
349 + */
350 +#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
351 +#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
352 +#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
353 +#define SCHED_PRIO(p) ((p)+MAX_RT_PRIO)
354 +
355 +/* Some helpers for converting to/from various scales.*/
356 +#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
357 +#define MS_TO_NS(TIME) ((TIME) * 1000000)
358 +#define MS_TO_US(TIME) ((TIME) * 1000)
359 +
360 +#ifdef CONFIG_SMP
361 +/*
362 + * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
363 + * Since cpu_power is a 'constant', we can use a reciprocal divide.
364 + */
365 +static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load)
366 +{
367 + return reciprocal_divide(load, sg->reciprocal_cpu_power);
368 +}
369 +
370 +/*
371 + * Each time a sched group cpu_power is changed,
372 + * we must compute its reciprocal value
373 + */
374 +static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
375 +{
376 + sg->__cpu_power += val;
377 + sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power);
378 +}
379 +#endif
380 +
381 +/*
382 + * This is the time all tasks within the same priority round robin.
383 + * Value is in ms and set to a minimum of 6ms. Scales with number of cpus.
384 + * Tunable via /proc interface.
385 + */
386 +int rr_interval __read_mostly = 6;
387 +
388 +/*
389 + * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks
390 + * are allowed to run five seconds as real time tasks. This is the total over
391 + * all online cpus.
392 + */
393 +int sched_iso_cpu __read_mostly = 70;
394 +
395 +int prio_ratios[PRIO_RANGE] __read_mostly;
396 +
397 +static inline unsigned long timeslice(void)
398 +{
399 + return MS_TO_US(rr_interval);
400 +}
401 +
402 +struct global_rq {
403 + spinlock_t lock;
404 + unsigned long nr_running;
405 + unsigned long nr_uninterruptible;
406 + unsigned long long nr_switches;
407 + struct list_head queue[PRIO_LIMIT];
408 + DECLARE_BITMAP(prio_bitmap, PRIO_LIMIT + 1);
409 + unsigned long iso_ticks;
410 + unsigned short iso_refractory;
411 +#ifdef CONFIG_SMP
412 + unsigned long qnr; /* queued not running */
413 + cpumask_t cpu_idle_map;
414 +#endif
415 +};
416 +
417 +static struct global_rq grq;
418 +
419 +/*
420 + * This is the main, per-CPU runqueue data structure.
421 + * All this is protected by the global_rq lock.
422 + */
423 +struct rq {
424 +#ifdef CONFIG_SMP
425 +#ifdef CONFIG_NO_HZ
426 + unsigned char in_nohz_recently;
427 +#endif
428 +#endif
429 +
430 + struct task_struct *curr, *idle;
431 + struct mm_struct *prev_mm;
432 + struct list_head queue; /* Place to store currently running task */
433 +
434 + /* Stored data about rq->curr to work outside grq lock */
435 + unsigned long rq_deadline;
436 + unsigned int rq_policy;
437 + int rq_time_slice;
438 + int rq_prio;
439 +
440 + /* Accurate timekeeping data */
441 + u64 timekeep_clock;
442 + unsigned long user_pc, nice_pc, irq_pc, softirq_pc, system_pc,
443 + iowait_pc, idle_pc;
444 + atomic_t nr_iowait;
445 +
446 + int cpu; /* cpu of this runqueue */
447 + int online;
448 +
449 +#ifdef CONFIG_SMP
450 + struct root_domain *rd;
451 + struct sched_domain *sd;
452 +
453 + struct list_head migration_queue;
454 +#endif
455 +
456 + u64 clock;
457 +#ifdef CONFIG_SCHEDSTATS
458 +
459 + /* latency stats */
460 + struct sched_info rq_sched_info;
461 + unsigned long long rq_cpu_time;
462 + /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
463 +
464 + /* sys_sched_yield() stats */
465 + unsigned int yld_count;
466 +
467 + /* schedule() stats */
468 + unsigned int sched_switch;
469 + unsigned int sched_count;
470 + unsigned int sched_goidle;
471 +
472 + /* try_to_wake_up() stats */
473 + unsigned int ttwu_count;
474 + unsigned int ttwu_local;
475 +
476 + /* BKL stats */
477 + unsigned int bkl_count;
478 +#endif
479 +};
480 +
481 +static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp;
482 +static DEFINE_MUTEX(sched_hotcpu_mutex);
483 +
484 +#ifdef CONFIG_SMP
485 +
486 +/*
487 + * We add the notion of a root-domain which will be used to define per-domain
488 + * variables. Each exclusive cpuset essentially defines an island domain by
489 + * fully partitioning the member cpus from any other cpuset. Whenever a new
490 + * exclusive cpuset is created, we also create and attach a new root-domain
491 + * object.
492 + *
493 + */
494 +struct root_domain {
495 + atomic_t refcount;
496 + cpumask_var_t span;
497 + cpumask_var_t online;
498 +
499 + /*
500 + * The "RT overload" flag: it gets set if a CPU has more than
501 + * one runnable RT task.
502 + */
503 + cpumask_var_t rto_mask;
504 + atomic_t rto_count;
505 +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
506 + /*
507 + * Preferred wake up cpu nominated by sched_mc balance that will be
508 + * used when most cpus are idle in the system indicating overall very
509 + * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
510 + */
511 + unsigned int sched_mc_preferred_wakeup_cpu;
512 +#endif
513 +};
514 +
515 +/*
516 + * By default the system creates a single root-domain with all cpus as
517 + * members (mimicking the global state we have today).
518 + */
519 +static struct root_domain def_root_domain;
520 +
521 +#endif
522 +
523 +static inline int cpu_of(struct rq *rq)
524 +{
525 +#ifdef CONFIG_SMP
526 + return rq->cpu;
527 +#else
528 + return 0;
529 +#endif
530 +}
531 +
532 +/*
533 + * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
534 + * See detach_destroy_domains: synchronize_sched for details.
535 + *
536 + * The domain tree of any CPU may only be accessed from within
537 + * preempt-disabled sections.
538 + */
539 +#define for_each_domain(cpu, __sd) \
540 + for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
541 +
542 +#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
543 +#define this_rq() (&__get_cpu_var(runqueues))
544 +#define task_rq(p) cpu_rq(task_cpu(p))
545 +#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
546 +
547 +#include "sched_stats.h"
548 +
549 +#ifndef prepare_arch_switch
550 +# define prepare_arch_switch(next) do { } while (0)
551 +#endif
552 +#ifndef finish_arch_switch
553 +# define finish_arch_switch(prev) do { } while (0)
554 +#endif
555 +
556 +inline void update_rq_clock(struct rq *rq)
557 +{
558 + rq->clock = sched_clock_cpu(cpu_of(rq));
559 +}
560 +
561 +static inline int task_running(struct task_struct *p)
562 +{
563 + return (!!p->oncpu);
564 +}
565 +
566 +static inline void grq_lock(void)
567 + __acquires(grq.lock)
568 +{
569 + smp_mb();
570 + spin_lock(&grq.lock);
571 +}
572 +
573 +static inline void grq_unlock(void)
574 + __releases(grq.lock)
575 +{
576 + spin_unlock(&grq.lock);
577 +}
578 +
579 +static inline void grq_lock_irq(void)
580 + __acquires(grq.lock)
581 +{
582 + smp_mb();
583 + spin_lock_irq(&grq.lock);
584 +}
585 +
586 +static inline void time_lock_grq(struct rq *rq)
587 + __acquires(grq.lock)
588 +{
589 + grq_lock();
590 + update_rq_clock(rq);
591 +}
592 +
593 +static inline void grq_unlock_irq(void)
594 + __releases(grq.lock)
595 +{
596 + spin_unlock_irq(&grq.lock);
597 +}
598 +
599 +static inline void grq_lock_irqsave(unsigned long *flags)
600 + __acquires(grq.lock)
601 +{
602 + smp_mb();
603 + spin_lock_irqsave(&grq.lock, *flags);
604 +}
605 +
606 +static inline void grq_unlock_irqrestore(unsigned long *flags)
607 + __releases(grq.lock)
608 +{
609 + spin_unlock_irqrestore(&grq.lock, *flags);
610 +}
611 +
612 +static inline struct rq
613 +*task_grq_lock(struct task_struct *p, unsigned long *flags)
614 + __acquires(grq.lock)
615 +{
616 + grq_lock_irqsave(flags);
617 + return task_rq(p);
618 +}
619 +
620 +static inline struct rq
621 +*time_task_grq_lock(struct task_struct *p, unsigned long *flags)
622 + __acquires(grq.lock)
623 +{
624 + struct rq *rq = task_grq_lock(p, flags);
625 + update_rq_clock(rq);
626 + return rq;
627 +}
628 +
629 +static inline void task_grq_unlock(unsigned long *flags)
630 + __releases(grq.lock)
631 +{
632 + grq_unlock_irqrestore(flags);
633 +}
634 +
635 +/**
636 + * runqueue_is_locked
637 + *
638 + * Returns true if the global runqueue is locked.
639 + * This interface allows printk to be called with the runqueue lock
640 + * held and know whether or not it is OK to wake up the klogd.
641 + */
642 +int runqueue_is_locked(void)
643 +{
644 + return spin_is_locked(&grq.lock);
645 +}
646 +
647 +void task_rq_unlock_wait(struct task_struct *p)
648 + __releases(grq.lock)
649 +{
650 + smp_mb(); /* spin-unlock-wait is not a full memory barrier */
651 + spin_unlock_wait(&grq.lock);
652 +}
653 +
654 +static inline void time_grq_lock(struct rq *rq, unsigned long *flags)
655 + __acquires(grq.lock)
656 +{
657 + spin_lock_irqsave(&grq.lock, *flags);
658 + update_rq_clock(rq);
659 +}
660 +
661 +static inline struct rq *__task_grq_lock(struct task_struct *p)
662 + __acquires(grq.lock)
663 +{
664 + grq_lock();
665 + return task_rq(p);
666 +}
667 +
668 +static inline void __task_grq_unlock(void)
669 + __releases(grq.lock)
670 +{
671 + grq_unlock();
672 +}
673 +
674 +#ifndef __ARCH_WANT_UNLOCKED_CTXSW
675 +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
676 +{
677 +}
678 +
679 +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
680 +{
681 +#ifdef CONFIG_DEBUG_SPINLOCK
682 + /* this is a valid case when another task releases the spinlock */
683 + grq.lock.owner = current;
684 +#endif
685 + /*
686 + * If we are tracking spinlock dependencies then we have to
687 + * fix up the runqueue lock - which gets 'carried over' from
688 + * prev into current:
689 + */
690 + spin_acquire(&grq.lock.dep_map, 0, 0, _THIS_IP_);
691 +
692 + grq_unlock_irq();
693 +}
694 +
695 +#else /* __ARCH_WANT_UNLOCKED_CTXSW */
696 +
697 +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
698 +{
699 +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
700 + grq_unlock_irq();
701 +#else
702 + grq_unlock();
703 +#endif
704 +}
705 +
706 +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
707 +{
708 + smp_wmb();
709 +#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
710 + local_irq_enable();
711 +#endif
712 +}
713 +#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
714 +
715 +/*
716 + * A task that is queued will be on the grq run list.
717 + * A task that is not running or queued will not be on the grq run list.
718 + * A task that is currently running will have ->oncpu set and be queued
719 + * temporarily in its own rq queue.
720 + * A task that is running and no longer queued will be seen only on
721 + * context switch exit.
722 + */
723 +
724 +static inline int task_queued(struct task_struct *p)
725 +{
726 + return (!list_empty(&p->rt.run_list));
727 +}
728 +
729 +static inline int task_queued_only(struct task_struct *p)
730 +{
731 + return (!list_empty(&p->rt.run_list) && !task_running(p));
732 +}
733 +
734 +/*
735 + * Removing from the global runqueue. Enter with grq locked.
736 + */
737 +static void dequeue_task(struct task_struct *p)
738 +{
739 + list_del_init(&p->rt.run_list);
740 + if (list_empty(grq.queue + p->prio))
741 + __clear_bit(p->prio, grq.prio_bitmap);
742 +}
743 +
744 +static inline void reset_first_time_slice(struct task_struct *p)
745 +{
746 + if (unlikely(p->first_time_slice))
747 + p->first_time_slice = 0;
748 +}
749 +
750 +static int idleprio_suitable(struct task_struct *p)
751 +{
752 + return (!freezing(p) && !signal_pending(p) &&
753 + !(task_contributes_to_load(p)) && !(p->flags & (PF_EXITING)));
754 +}
755 +
756 +static int isoprio_suitable(void)
757 +{
758 + return !grq.iso_refractory;
759 +}
760 +
761 +/*
762 + * Adding to the global runqueue. Enter with grq locked.
763 + */
764 +static void enqueue_task(struct task_struct *p)
765 +{
766 + if (!rt_task(p)) {
767 + /* Check it hasn't gotten rt from PI */
768 + if ((idleprio_task(p) && idleprio_suitable(p)) ||
769 + (iso_task(p) && isoprio_suitable()))
770 + p->prio = p->normal_prio;
771 + else
772 + p->prio = NORMAL_PRIO;
773 + }
774 + __set_bit(p->prio, grq.prio_bitmap);
775 + list_add_tail(&p->rt.run_list, grq.queue + p->prio);
776 + sched_info_queued(p);
777 +}
778 +
779 +/* Only idle task does this as a real time task*/
780 +static inline void enqueue_task_head(struct task_struct *p)
781 +{
782 + __set_bit(p->prio, grq.prio_bitmap);
783 + list_add(&p->rt.run_list, grq.queue + p->prio);
784 + sched_info_queued(p);
785 +}
786 +
787 +static inline void requeue_task(struct task_struct *p)
788 +{
789 + sched_info_queued(p);
790 +}
791 +
792 +static inline int pratio(struct task_struct *p)
793 +{
794 + return prio_ratios[TASK_USER_PRIO(p)];
795 +}
796 +
797 +/*
798 + * task_timeslice - all tasks of all priorities get the exact same timeslice
799 + * length. CPU distribution is handled by giving different deadlines to
800 + * tasks of different priorities.
801 + */
802 +static inline int task_timeslice(struct task_struct *p)
803 +{
804 + return (rr_interval * pratio(p) / 100);
805 +}
806 +
807 +#ifdef CONFIG_SMP
808 +static inline void inc_qnr(void)
809 +{
810 + grq.qnr++;
811 +}
812 +
813 +static inline void dec_qnr(void)
814 +{
815 + grq.qnr--;
816 +}
817 +
818 +static inline int queued_notrunning(void)
819 +{
820 + return grq.qnr;
821 +}
822 +#else
823 +static inline void inc_qnr(void)
824 +{
825 +}
826 +
827 +static inline void dec_qnr(void)
828 +{
829 +}
830 +
831 +static inline int queued_notrunning(void)
832 +{
833 + return grq.nr_running;
834 +}
835 +#endif
836 +
837 +/*
838 + * activate_idle_task - move idle task to the _front_ of runqueue.
839 + */
840 +static inline void activate_idle_task(struct task_struct *p)
841 +{
842 + enqueue_task_head(p);
843 + grq.nr_running++;
844 + inc_qnr();
845 +}
846 +
847 +static inline int normal_prio(struct task_struct *p)
848 +{
849 + if (has_rt_policy(p))
850 + return MAX_RT_PRIO - 1 - p->rt_priority;
851 + if (idleprio_task(p))
852 + return IDLE_PRIO;
853 + if (iso_task(p))
854 + return ISO_PRIO;
855 + return NORMAL_PRIO;
856 +}
857 +
858 +/*
859 + * Calculate the current priority, i.e. the priority
860 + * taken into account by the scheduler. This value might
861 + * be boosted by RT tasks as it will be RT if the task got
862 + * RT-boosted. If not then it returns p->normal_prio.
863 + */
864 +static int effective_prio(struct task_struct *p)
865 +{
866 + p->normal_prio = normal_prio(p);
867 + /*
868 + * If we are RT tasks or we were boosted to RT priority,
869 + * keep the priority unchanged. Otherwise, update priority
870 + * to the normal priority:
871 + */
872 + if (!rt_prio(p->prio))
873 + return p->normal_prio;
874 + return p->prio;
875 +}
876 +
877 +/*
878 + * activate_task - move a task to the runqueue. Enter with grq locked. The rq
879 + * doesn't really matter but gives us the local clock.
880 + */
881 +static void activate_task(struct task_struct *p, struct rq *rq)
882 +{
883 + u64 now = rq->clock;
884 +
885 + /*
886 + * Sleep time is in units of nanosecs, so shift by 20 to get a
887 + * milliseconds-range estimation of the amount of time that the task
888 + * spent sleeping:
889 + */
890 + if (unlikely(prof_on == SLEEP_PROFILING)) {
891 + if (p->state == TASK_UNINTERRUPTIBLE)
892 + profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
893 + (now - p->timestamp) >> 20);
894 + }
895 +
896 + p->prio = effective_prio(p);
897 + p->timestamp = now;
898 + if (task_contributes_to_load(p))
899 + grq.nr_uninterruptible--;
900 + enqueue_task(p);
901 + grq.nr_running++;
902 + inc_qnr();
903 +}
904 +
905 +/*
906 + * deactivate_task - If it's running, it's not on the grq and we can just
907 + * decrement the nr_running.
908 + */
909 +static inline void deactivate_task(struct task_struct *p)
910 +{
911 + if (task_contributes_to_load(p))
912 + grq.nr_uninterruptible++;
913 + grq.nr_running--;
914 +}
915 +
916 +#ifdef CONFIG_SMP
917 +void set_task_cpu(struct task_struct *p, unsigned int cpu)
918 +{
919 + trace_sched_migrate_task(p, cpu);
920 + /*
921 + * After ->cpu is set up to a new value, task_grq_lock(p, ...) can be
922 + * successfuly executed on another CPU. We must ensure that updates of
923 + * per-task data have been completed by this moment.
924 + */
925 + smp_wmb();
926 + task_thread_info(p)->cpu = cpu;
927 +}
928 +#endif
929 +
930 +/*
931 + * Move a task off the global queue and take it to a cpu for it will
932 + * become the running task.
933 + */
934 +static inline void take_task(struct rq *rq, struct task_struct *p)
935 +{
936 + set_task_cpu(p, rq->cpu);
937 + dequeue_task(p);
938 + list_add(&p->rt.run_list, &rq->queue);
939 + dec_qnr();
940 +}
941 +
942 +/*
943 + * Returns a descheduling task to the grq runqueue unless it is being
944 + * deactivated.
945 + */
946 +static inline void return_task(struct task_struct *p, int deactivate)
947 +{
948 + list_del_init(&p->rt.run_list);
949 + if (deactivate)
950 + deactivate_task(p);
951 + else {
952 + inc_qnr();
953 + enqueue_task(p);
954 + }
955 +}
956 +
957 +/*
958 + * resched_task - mark a task 'to be rescheduled now'.
959 + *
960 + * On UP this means the setting of the need_resched flag, on SMP it
961 + * might also involve a cross-CPU call to trigger the scheduler on
962 + * the target CPU.
963 + */
964 +#ifdef CONFIG_SMP
965 +
966 +#ifndef tsk_is_polling
967 +#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
968 +#endif
969 +
970 +static void resched_task(struct task_struct *p)
971 +{
972 + int cpu;
973 +
974 + assert_spin_locked(&grq.lock);
975 +
976 + if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
977 + return;
978 +
979 + set_tsk_thread_flag(p, TIF_NEED_RESCHED);
980 +
981 + cpu = task_cpu(p);
982 + if (cpu == smp_processor_id())
983 + return;
984 +
985 + /* NEED_RESCHED must be visible before we test polling */
986 + smp_mb();
987 + if (!tsk_is_polling(p))
988 + smp_send_reschedule(cpu);
989 +}
990 +
991 +#else
992 +static inline void resched_task(struct task_struct *p)
993 +{
994 + assert_spin_locked(&grq.lock);
995 + set_tsk_need_resched(p);
996 +}
997 +#endif
998 +
999 +/**
1000 + * task_curr - is this task currently executing on a CPU?
1001 + * @p: the task in question.
1002 + */
1003 +inline int task_curr(const struct task_struct *p)
1004 +{
1005 + return cpu_curr(task_cpu(p)) == p;
1006 +}
1007 +
1008 +#ifdef CONFIG_SMP
1009 +struct migration_req {
1010 + struct list_head list;
1011 +
1012 + struct task_struct *task;
1013 + int dest_cpu;
1014 +
1015 + struct completion done;
1016 +};
1017 +
1018 +/*
1019 + * wait_task_context_switch - wait for a thread to complete at least one
1020 + * context switch.
1021 + *
1022 + * @p must not be current.
1023 + */
1024 +void wait_task_context_switch(struct task_struct *p)
1025 +{
1026 + unsigned long nvcsw, nivcsw, flags;
1027 + int running;
1028 + struct rq *rq;
1029 +
1030 + nvcsw = p->nvcsw;
1031 + nivcsw = p->nivcsw;
1032 + for (;;) {
1033 + /*
1034 + * The runqueue is assigned before the actual context
1035 + * switch. We need to take the runqueue lock.
1036 + *
1037 + * We could check initially without the lock but it is
1038 + * very likely that we need to take the lock in every
1039 + * iteration.
1040 + */
1041 + rq = task_grq_lock(p, &flags);
1042 + running = task_running(p);
1043 + task_grq_unlock(&flags);
1044 +
1045 + if (likely(!running))
1046 + break;
1047 + /*
1048 + * The switch count is incremented before the actual
1049 + * context switch. We thus wait for two switches to be
1050 + * sure at least one completed.
1051 + */
1052 + if ((p->nvcsw - nvcsw) > 1)
1053 + break;
1054 + if ((p->nivcsw - nivcsw) > 1)
1055 + break;
1056 +
1057 + cpu_relax();
1058 + }
1059 +}
1060 +
1061 +/*
1062 + * wait_task_inactive - wait for a thread to unschedule.
1063 + *
1064 + * If @match_state is nonzero, it's the @p->state value just checked and
1065 + * not expected to change. If it changes, i.e. @p might have woken up,
1066 + * then return zero. When we succeed in waiting for @p to be off its CPU,
1067 + * we return a positive number (its total switch count). If a second call
1068 + * a short while later returns the same number, the caller can be sure that
1069 + * @p has remained unscheduled the whole time.
1070 + *
1071 + * The caller must ensure that the task *will* unschedule sometime soon,
1072 + * else this function might spin for a *long* time. This function can't
1073 + * be called with interrupts off, or it may introduce deadlock with
1074 + * smp_call_function() if an IPI is sent by the same process we are
1075 + * waiting to become inactive.
1076 + */
1077 +unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1078 +{
1079 + unsigned long flags;
1080 + int running, on_rq;
1081 + unsigned long ncsw;
1082 + struct rq *rq;
1083 +
1084 + for (;;) {
1085 + /*
1086 + * We do the initial early heuristics without holding
1087 + * any task-queue locks at all. We'll only try to get
1088 + * the runqueue lock when things look like they will
1089 + * work out!
1090 + */
1091 + rq = task_rq(p);
1092 +
1093 + /*
1094 + * If the task is actively running on another CPU
1095 + * still, just relax and busy-wait without holding
1096 + * any locks.
1097 + *
1098 + * NOTE! Since we don't hold any locks, it's not
1099 + * even sure that "rq" stays as the right runqueue!
1100 + * But we don't care, since this will
1101 + * return false if the runqueue has changed and p
1102 + * is actually now running somewhere else!
1103 + */
1104 + while (task_running(p) && p == rq->curr) {
1105 + if (match_state && unlikely(p->state != match_state))
1106 + return 0;
1107 + cpu_relax();
1108 + }
1109 +
1110 + /*
1111 + * Ok, time to look more closely! We need the grq
1112 + * lock now, to be *sure*. If we're wrong, we'll
1113 + * just go back and repeat.
1114 + */
1115 + rq = task_grq_lock(p, &flags);
1116 + trace_sched_wait_task(rq, p);
1117 + running = task_running(p);
1118 + on_rq = task_queued(p);
1119 + ncsw = 0;
1120 + if (!match_state || p->state == match_state)
1121 + ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
1122 + task_grq_unlock(&flags);
1123 +
1124 + /*
1125 + * If it changed from the expected state, bail out now.
1126 + */
1127 + if (unlikely(!ncsw))
1128 + break;
1129 +
1130 + /*
1131 + * Was it really running after all now that we
1132 + * checked with the proper locks actually held?
1133 + *
1134 + * Oops. Go back and try again..
1135 + */
1136 + if (unlikely(running)) {
1137 + cpu_relax();
1138 + continue;
1139 + }
1140 +
1141 + /*
1142 + * It's not enough that it's not actively running,
1143 + * it must be off the runqueue _entirely_, and not
1144 + * preempted!
1145 + *
1146 + * So if it was still runnable (but just not actively
1147 + * running right now), it's preempted, and we should
1148 + * yield - it could be a while.
1149 + */
1150 + if (unlikely(on_rq)) {
1151 + schedule_timeout_uninterruptible(1);
1152 + continue;
1153 + }
1154 +
1155 + /*
1156 + * Ahh, all good. It wasn't running, and it wasn't
1157 + * runnable, which means that it will never become
1158 + * running in the future either. We're all done!
1159 + */
1160 + break;
1161 + }
1162 +
1163 + return ncsw;
1164 +}
1165 +
1166 +/***
1167 + * kick_process - kick a running thread to enter/exit the kernel
1168 + * @p: the to-be-kicked thread
1169 + *
1170 + * Cause a process which is running on another CPU to enter
1171 + * kernel-mode, without any delay. (to get signals handled.)
1172 + *
1173 + * NOTE: this function doesnt have to take the runqueue lock,
1174 + * because all it wants to ensure is that the remote task enters
1175 + * the kernel. If the IPI races and the task has been migrated
1176 + * to another CPU then no harm is done and the purpose has been
1177 + * achieved as well.
1178 + */
1179 +void kick_process(struct task_struct *p)
1180 +{
1181 + int cpu;
1182 +
1183 + preempt_disable();
1184 + cpu = task_cpu(p);
1185 + if ((cpu != smp_processor_id()) && task_curr(p))
1186 + smp_send_reschedule(cpu);
1187 + preempt_enable();
1188 +}
1189 +EXPORT_SYMBOL_GPL(kick_process);
1190 +#endif
1191 +
1192 +#define rq_idle(rq) ((rq)->rq_prio == PRIO_LIMIT)
1193 +
1194 +/*
1195 + * RT tasks preempt purely on priority. SCHED_NORMAL tasks preempt on the
1196 + * basis of earlier deadlines. SCHED_BATCH and SCHED_IDLE don't preempt,
1197 + * they cooperatively multitask.
1198 + */
1199 +static inline int task_preempts_curr(struct task_struct *p, struct rq *rq)
1200 +{
1201 + int preempts = 0;
1202 +
1203 + if (p->prio < rq->rq_prio)
1204 + preempts = 1;
1205 + else if (p->policy == SCHED_NORMAL && (p->prio == rq->rq_prio &&
1206 + time_before(p->deadline, rq->rq_deadline)))
1207 + preempts = 1;
1208 + return preempts;
1209 +}
1210 +
1211 +/*
1212 + * Wake up *any* suitable cpu to schedule this task.
1213 + */
1214 +static void try_preempt(struct task_struct *p)
1215 +{
1216 + struct rq *highest_prio_rq, *this_rq;
1217 + unsigned long latest_deadline, cpu;
1218 + int highest_prio;
1219 + cpumask_t tmp;
1220 +
1221 + /* Try the task's previous rq first and as a fallback */
1222 + this_rq = task_rq(p);
1223 +
1224 + if (cpu_isset(this_rq->cpu, p->cpus_allowed)) {
1225 + highest_prio_rq = this_rq;
1226 + /* If this_rq is idle, use that. */
1227 + if (rq_idle(this_rq))
1228 + goto found_rq;
1229 + } else
1230 + highest_prio_rq = cpu_rq(any_online_cpu(p->cpus_allowed));
1231 + latest_deadline = this_rq->rq_deadline;
1232 + highest_prio = this_rq->rq_prio;
1233 +
1234 + cpus_and(tmp, cpu_online_map, p->cpus_allowed);
1235 +
1236 + for_each_cpu_mask(cpu, tmp) {
1237 + struct rq *rq;
1238 + int rq_prio;
1239 +
1240 + rq = cpu_rq(cpu);
1241 +
1242 + if (rq_idle(rq)) {
1243 + /* found an idle rq, use that one */
1244 + highest_prio_rq = rq;
1245 + goto found_rq;
1246 + }
1247 +
1248 + rq_prio = rq->rq_prio;
1249 + if (rq_prio > highest_prio ||
1250 + (rq_prio == highest_prio &&
1251 + time_after(rq->rq_deadline, latest_deadline))) {
1252 + highest_prio = rq_prio;
1253 + latest_deadline = rq->rq_deadline;
1254 + highest_prio_rq = rq;
1255 + }
1256 + }
1257 +
1258 + if (!task_preempts_curr(p, highest_prio_rq))
1259 + return;
1260 +found_rq:
1261 + resched_task(highest_prio_rq->curr);
1262 + return;
1263 +}
1264 +
1265 +/**
1266 + * task_oncpu_function_call - call a function on the cpu on which a task runs
1267 + * @p: the task to evaluate
1268 + * @func: the function to be called
1269 + * @info: the function call argument
1270 + *
1271 + * Calls the function @func when the task is currently running. This might
1272 + * be on the current CPU, which just calls the function directly
1273 + */
1274 +void task_oncpu_function_call(struct task_struct *p,
1275 + void (*func) (void *info), void *info)
1276 +{
1277 + int cpu;
1278 +
1279 + preempt_disable();
1280 + cpu = task_cpu(p);
1281 + if (task_curr(p))
1282 + smp_call_function_single(cpu, func, info, 1);
1283 + preempt_enable();
1284 +}
1285 +
1286 +#ifdef CONFIG_SMP
1287 +static int suitable_idle_cpus(struct task_struct *p)
1288 +{
1289 + return (cpus_intersects(p->cpus_allowed, grq.cpu_idle_map));
1290 +}
1291 +#else
1292 +static int suitable_idle_cpus(struct task_struct *p)
1293 +{
1294 + return 0;
1295 +}
1296 +#endif
1297 +
1298 +/***
1299 + * try_to_wake_up - wake up a thread
1300 + * @p: the to-be-woken-up thread
1301 + * @state: the mask of task states that can be woken
1302 + * @sync: do a synchronous wakeup?
1303 + *
1304 + * Put it on the run-queue if it's not already there. The "current"
1305 + * thread is always on the run-queue (except when the actual
1306 + * re-schedule is in progress), and as such you're allowed to do
1307 + * the simpler "current->state = TASK_RUNNING" to mark yourself
1308 + * runnable without the overhead of this.
1309 + *
1310 + * returns failure only if the task is already active.
1311 + */
1312 +static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
1313 +{
1314 + unsigned long flags;
1315 + int success = 0;
1316 + long old_state;
1317 + struct rq *rq;
1318 +
1319 + rq = time_task_grq_lock(p, &flags);
1320 + old_state = p->state;
1321 + if (!(old_state & state))
1322 + goto out_unlock;
1323 +
1324 + /*
1325 + * Note this catches tasks that are running and queued, but returns
1326 + * false during the context switch when they're running and no
1327 + * longer queued.
1328 + */
1329 + if (task_queued(p))
1330 + goto out_running;
1331 +
1332 + activate_task(p, rq);
1333 + /*
1334 + * Sync wakeups (i.e. those types of wakeups where the waker
1335 + * has indicated that it will leave the CPU in short order)
1336 + * don't trigger a preemption if there are no idle cpus,
1337 + * instead waiting for current to deschedule.
1338 + */
1339 + if (!sync || (sync && suitable_idle_cpus(p)))
1340 + try_preempt(p);
1341 + success = 1;
1342 +
1343 +out_running:
1344 + trace_sched_wakeup(rq, p, success);
1345 + p->state = TASK_RUNNING;
1346 +out_unlock:
1347 + task_grq_unlock(&flags);
1348 + return success;
1349 +}
1350 +
1351 +/**
1352 + * wake_up_process - Wake up a specific process
1353 + * @p: The process to be woken up.
1354 + *
1355 + * Attempt to wake up the nominated process and move it to the set of runnable
1356 + * processes. Returns 1 if the process was woken up, 0 if it was already
1357 + * running.
1358 + *
1359 + * It may be assumed that this function implies a write memory barrier before
1360 + * changing the task state if and only if any tasks are woken up.
1361 + */
1362 +int wake_up_process(struct task_struct *p)
1363 +{
1364 + return try_to_wake_up(p, TASK_ALL, 0);
1365 +}
1366 +EXPORT_SYMBOL(wake_up_process);
1367 +
1368 +int wake_up_state(struct task_struct *p, unsigned int state)
1369 +{
1370 + return try_to_wake_up(p, state, 0);
1371 +}
1372 +
1373 +/*
1374 + * Perform scheduler related setup for a newly forked process p.
1375 + * p is forked by current.
1376 + */
1377 +void sched_fork(struct task_struct *p, int clone_flags)
1378 +{
1379 + int cpu = get_cpu();
1380 + struct rq *rq;
1381 +
1382 +#ifdef CONFIG_PREEMPT_NOTIFIERS
1383 + INIT_HLIST_HEAD(&p->preempt_notifiers);
1384 +#endif
1385 + /*
1386 + * We mark the process as running here, but have not actually
1387 + * inserted it onto the runqueue yet. This guarantees that
1388 + * nobody will actually run it, and a signal or other external
1389 + * event cannot wake it up and insert it on the runqueue either.
1390 + */
1391 + p->state = TASK_RUNNING;
1392 + set_task_cpu(p, cpu);
1393 +
1394 + /* Should be reset in fork.c but done here for ease of bfs patching */
1395 + p->se.sum_exec_runtime = p->stime_pc = p->utime_pc = 0;
1396 +
1397 + /*
1398 + * Make sure we do not leak PI boosting priority to the child:
1399 + */
1400 + p->prio = current->normal_prio;
1401 +
1402 + INIT_LIST_HEAD(&p->rt.run_list);
1403 +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1404 + if (unlikely(sched_info_on()))
1405 + memset(&p->sched_info, 0, sizeof(p->sched_info));
1406 +#endif
1407 +
1408 + p->oncpu = 0;
1409 +
1410 +#ifdef CONFIG_PREEMPT
1411 + /* Want to start with kernel preemption disabled. */
1412 + task_thread_info(p)->preempt_count = 1;
1413 +#endif
1414 + if (unlikely(p->policy == SCHED_FIFO))
1415 + goto out;
1416 + /*
1417 + * Share the timeslice between parent and child, thus the
1418 + * total amount of pending timeslices in the system doesn't change,
1419 + * resulting in more scheduling fairness. If it's negative, it won't
1420 + * matter since that's the same as being 0. current's time_slice is
1421 + * actually in rq_time_slice when it's running.
1422 + */
1423 + local_irq_disable();
1424 + rq = task_rq(current);
1425 + if (likely(rq->rq_time_slice > 0)) {
1426 + rq->rq_time_slice /= 2;
1427 + /*
1428 + * The remainder of the first timeslice might be recovered by
1429 + * the parent if the child exits early enough.
1430 + */
1431 + p->first_time_slice = 1;
1432 + }
1433 + p->rt.time_slice = rq->rq_time_slice;
1434 + local_irq_enable();
1435 +out:
1436 + put_cpu();
1437 +}
1438 +
1439 +/*
1440 + * wake_up_new_task - wake up a newly created task for the first time.
1441 + *
1442 + * This function will do some initial scheduler statistics housekeeping
1443 + * that must be done for every newly created context, then puts the task
1444 + * on the runqueue and wakes it.
1445 + */
1446 +void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
1447 +{
1448 + struct task_struct *parent;
1449 + unsigned long flags;
1450 + struct rq *rq;
1451 +
1452 + rq = time_task_grq_lock(p, &flags); ;
1453 + parent = p->parent;
1454 + BUG_ON(p->state != TASK_RUNNING);
1455 + set_task_cpu(p, task_cpu(parent));
1456 +
1457 + activate_task(p, rq);
1458 + trace_sched_wakeup_new(rq, p, 1);
1459 + if (!(clone_flags & CLONE_VM) && rq->curr == parent &&
1460 + !suitable_idle_cpus(p)) {
1461 + /*
1462 + * The VM isn't cloned, so we're in a good position to
1463 + * do child-runs-first in anticipation of an exec. This
1464 + * usually avoids a lot of COW overhead.
1465 + */
1466 + resched_task(parent);
1467 + } else
1468 + try_preempt(p);
1469 + task_grq_unlock(&flags);
1470 +}
1471 +
1472 +/*
1473 + * Potentially available exiting-child timeslices are
1474 + * retrieved here - this way the parent does not get
1475 + * penalized for creating too many threads.
1476 + *
1477 + * (this cannot be used to 'generate' timeslices
1478 + * artificially, because any timeslice recovered here
1479 + * was given away by the parent in the first place.)
1480 + */
1481 +void sched_exit(struct task_struct *p)
1482 +{
1483 + struct task_struct *parent;
1484 + unsigned long flags;
1485 + struct rq *rq;
1486 +
1487 + if (p->first_time_slice) {
1488 + parent = p->parent;
1489 + rq = task_grq_lock(parent, &flags);
1490 + parent->rt.time_slice += p->rt.time_slice;
1491 + if (unlikely(parent->rt.time_slice > timeslice()))
1492 + parent->rt.time_slice = timeslice();
1493 + task_grq_unlock(&flags);
1494 + }
1495 +}
1496 +
1497 +#ifdef CONFIG_PREEMPT_NOTIFIERS
1498 +
1499 +/**
1500 + * preempt_notifier_register - tell me when current is being preempted & rescheduled
1501 + * @notifier: notifier struct to register
1502 + */
1503 +void preempt_notifier_register(struct preempt_notifier *notifier)
1504 +{
1505 + hlist_add_head(&notifier->link, &current->preempt_notifiers);
1506 +}
1507 +EXPORT_SYMBOL_GPL(preempt_notifier_register);
1508 +
1509 +/**
1510 + * preempt_notifier_unregister - no longer interested in preemption notifications
1511 + * @notifier: notifier struct to unregister
1512 + *
1513 + * This is safe to call from within a preemption notifier.
1514 + */
1515 +void preempt_notifier_unregister(struct preempt_notifier *notifier)
1516 +{
1517 + hlist_del(&notifier->link);
1518 +}
1519 +EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
1520 +
1521 +static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
1522 +{
1523 + struct preempt_notifier *notifier;
1524 + struct hlist_node *node;
1525 +
1526 + hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
1527 + notifier->ops->sched_in(notifier, raw_smp_processor_id());
1528 +}
1529 +
1530 +static void
1531 +fire_sched_out_preempt_notifiers(struct task_struct *curr,
1532 + struct task_struct *next)
1533 +{
1534 + struct preempt_notifier *notifier;
1535 + struct hlist_node *node;
1536 +
1537 + hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
1538 + notifier->ops->sched_out(notifier, next);
1539 +}
1540 +
1541 +#else /* !CONFIG_PREEMPT_NOTIFIERS */
1542 +
1543 +static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
1544 +{
1545 +}
1546 +
1547 +static void
1548 +fire_sched_out_preempt_notifiers(struct task_struct *curr,
1549 + struct task_struct *next)
1550 +{
1551 +}
1552 +
1553 +#endif /* CONFIG_PREEMPT_NOTIFIERS */
1554 +
1555 +/**
1556 + * prepare_task_switch - prepare to switch tasks
1557 + * @rq: the runqueue preparing to switch
1558 + * @next: the task we are going to switch to.
1559 + *
1560 + * This is called with the rq lock held and interrupts off. It must
1561 + * be paired with a subsequent finish_task_switch after the context
1562 + * switch.
1563 + *
1564 + * prepare_task_switch sets up locking and calls architecture specific
1565 + * hooks.
1566 + */
1567 +static inline void
1568 +prepare_task_switch(struct rq *rq, struct task_struct *prev,
1569 + struct task_struct *next)
1570 +{
1571 + fire_sched_out_preempt_notifiers(prev, next);
1572 + prepare_lock_switch(rq, next);
1573 + prepare_arch_switch(next);
1574 +}
1575 +
1576 +/**
1577 + * finish_task_switch - clean up after a task-switch
1578 + * @rq: runqueue associated with task-switch
1579 + * @prev: the thread we just switched away from.
1580 + *
1581 + * finish_task_switch must be called after the context switch, paired
1582 + * with a prepare_task_switch call before the context switch.
1583 + * finish_task_switch will reconcile locking set up by prepare_task_switch,
1584 + * and do any other architecture-specific cleanup actions.
1585 + *
1586 + * Note that we may have delayed dropping an mm in context_switch(). If
1587 + * so, we finish that here outside of the runqueue lock. (Doing it
1588 + * with the lock held can cause deadlocks; see schedule() for
1589 + * details.)
1590 + */
1591 +static inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
1592 + __releases(grq.lock)
1593 +{
1594 + struct mm_struct *mm = rq->prev_mm;
1595 + long prev_state;
1596 +
1597 + rq->prev_mm = NULL;
1598 +
1599 + /*
1600 + * A task struct has one reference for the use as "current".
1601 + * If a task dies, then it sets TASK_DEAD in tsk->state and calls
1602 + * schedule one last time. The schedule call will never return, and
1603 + * the scheduled task must drop that reference.
1604 + * The test for TASK_DEAD must occur while the runqueue locks are
1605 + * still held, otherwise prev could be scheduled on another cpu, die
1606 + * there before we look at prev->state, and then the reference would
1607 + * be dropped twice.
1608 + * Manfred Spraul <manfred@colorfullife.com>
1609 + */
1610 + prev_state = prev->state;
1611 + finish_arch_switch(prev);
1612 + perf_counter_task_sched_in(current, cpu_of(rq));
1613 + finish_lock_switch(rq, prev);
1614 +
1615 + fire_sched_in_preempt_notifiers(current);
1616 + if (mm)
1617 + mmdrop(mm);
1618 + if (unlikely(prev_state == TASK_DEAD)) {
1619 + /*
1620 + * Remove function-return probe instances associated with this
1621 + * task and put them back on the free list.
1622 + */
1623 + kprobe_flush_task(prev);
1624 + put_task_struct(prev);
1625 + }
1626 +}
1627 +
1628 +/**
1629 + * schedule_tail - first thing a freshly forked thread must call.
1630 + * @prev: the thread we just switched away from.
1631 + */
1632 +asmlinkage void schedule_tail(struct task_struct *prev)
1633 + __releases(grq.lock)
1634 +{
1635 + struct rq *rq = this_rq();
1636 +
1637 + finish_task_switch(rq, prev);
1638 +#ifdef __ARCH_WANT_UNLOCKED_CTXSW
1639 + /* In this case, finish_task_switch does not reenable preemption */
1640 + preempt_enable();
1641 +#endif
1642 + if (current->set_child_tid)
1643 + put_user(current->pid, current->set_child_tid);
1644 +}
1645 +
1646 +/*
1647 + * context_switch - switch to the new MM and the new
1648 + * thread's register state.
1649 + */
1650 +static inline void
1651 +context_switch(struct rq *rq, struct task_struct *prev,
1652 + struct task_struct *next)
1653 +{
1654 + struct mm_struct *mm, *oldmm;
1655 +
1656 + prepare_task_switch(rq, prev, next);
1657 + trace_sched_switch(rq, prev, next);
1658 + mm = next->mm;
1659 + oldmm = prev->active_mm;
1660 + /*
1661 + * For paravirt, this is coupled with an exit in switch_to to
1662 + * combine the page table reload and the switch backend into
1663 + * one hypercall.
1664 + */
1665 + arch_start_context_switch(prev);
1666 +
1667 + if (unlikely(!mm)) {
1668 + next->active_mm = oldmm;
1669 + atomic_inc(&oldmm->mm_count);
1670 + enter_lazy_tlb(oldmm, next);
1671 + } else
1672 + switch_mm(oldmm, mm, next);
1673 +
1674 + if (unlikely(!prev->mm)) {
1675 + prev->active_mm = NULL;
1676 + rq->prev_mm = oldmm;
1677 + }
1678 + /*
1679 + * Since the runqueue lock will be released by the next
1680 + * task (which is an invalid locking op but in the case
1681 + * of the scheduler it's an obvious special-case), so we
1682 + * do an early lockdep release here:
1683 + */
1684 +#ifndef __ARCH_WANT_UNLOCKED_CTXSW
1685 + spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
1686 +#endif
1687 +
1688 + /* Here we just switch the register state and the stack. */
1689 + switch_to(prev, next, prev);
1690 +
1691 + barrier();
1692 + /*
1693 + * this_rq must be evaluated again because prev may have moved
1694 + * CPUs since it called schedule(), thus the 'rq' on its stack
1695 + * frame will be invalid.
1696 + */
1697 + finish_task_switch(this_rq(), prev);
1698 +}
1699 +
1700 +/*
1701 + * nr_running, nr_uninterruptible and nr_context_switches:
1702 + *
1703 + * externally visible scheduler statistics: current number of runnable
1704 + * threads, current number of uninterruptible-sleeping threads, total
1705 + * number of context switches performed since bootup. All are measured
1706 + * without grabbing the grq lock but the occasional inaccurate result
1707 + * doesn't matter so long as it's positive.
1708 + */
1709 +unsigned long nr_running(void)
1710 +{
1711 + long nr = grq.nr_running;
1712 +
1713 + if (unlikely(nr < 0))
1714 + nr = 0;
1715 + return (unsigned long)nr;
1716 +}
1717 +
1718 +unsigned long nr_uninterruptible(void)
1719 +{
1720 + unsigned long nu = grq.nr_uninterruptible;
1721 +
1722 + if (unlikely(nu < 0))
1723 + nu = 0;
1724 + return nu;
1725 +}
1726 +
1727 +unsigned long long nr_context_switches(void)
1728 +{
1729 + long long ns = grq.nr_switches;
1730 +
1731 + /* This is of course impossible */
1732 + if (unlikely(ns < 0))
1733 + ns = 1;
1734 + return (long long)ns;
1735 +}
1736 +
1737 +unsigned long nr_iowait(void)
1738 +{
1739 + unsigned long i, sum = 0;
1740 +
1741 + for_each_possible_cpu(i)
1742 + sum += atomic_read(&cpu_rq(i)->nr_iowait);
1743 +
1744 + return sum;
1745 +}
1746 +
1747 +unsigned long nr_active(void)
1748 +{
1749 + return nr_running() + nr_uninterruptible();
1750 +}
1751 +
1752 +/* Variables and functions for calc_load */
1753 +static unsigned long calc_load_update;
1754 +unsigned long avenrun[3];
1755 +EXPORT_SYMBOL(avenrun);
1756 +
1757 +/**
1758 + * get_avenrun - get the load average array
1759 + * @loads: pointer to dest load array
1760 + * @offset: offset to add
1761 + * @shift: shift count to shift the result left
1762 + *
1763 + * These values are estimates at best, so no need for locking.
1764 + */
1765 +void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
1766 +{
1767 + loads[0] = (avenrun[0] + offset) << shift;
1768 + loads[1] = (avenrun[1] + offset) << shift;
1769 + loads[2] = (avenrun[2] + offset) << shift;
1770 +}
1771 +
1772 +static unsigned long
1773 +calc_load(unsigned long load, unsigned long exp, unsigned long active)
1774 +{
1775 + load *= exp;
1776 + load += active * (FIXED_1 - exp);
1777 + return load >> FSHIFT;
1778 +}
1779 +
1780 +/*
1781 + * calc_load - update the avenrun load estimates every LOAD_FREQ seconds.
1782 + */
1783 +void calc_global_load(void)
1784 +{
1785 + long active;
1786 +
1787 + if (time_before(jiffies, calc_load_update))
1788 + return;
1789 + active = nr_active() * FIXED_1;
1790 +
1791 + avenrun[0] = calc_load(avenrun[0], EXP_1, active);
1792 + avenrun[1] = calc_load(avenrun[1], EXP_5, active);
1793 + avenrun[2] = calc_load(avenrun[2], EXP_15, active);
1794 +
1795 + calc_load_update = jiffies + LOAD_FREQ;
1796 +}
1797 +
1798 +DEFINE_PER_CPU(struct kernel_stat, kstat);
1799 +
1800 +EXPORT_PER_CPU_SYMBOL(kstat);
1801 +
1802 +/*
1803 + * On each tick, see what percentage of that tick was attributed to each
1804 + * component and add the percentage to the _pc values. Once a _pc value has
1805 + * accumulated one tick's worth, account for that. This means the total
1806 + * percentage of load components will always be 100 per tick.
1807 + */
1808 +static void pc_idle_time(struct rq *rq, unsigned long pc)
1809 +{
1810 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1811 + cputime64_t tmp = cputime_to_cputime64(jiffies_to_cputime(1));
1812 +
1813 + if (atomic_read(&rq->nr_iowait) > 0) {
1814 + rq->iowait_pc += pc;
1815 + if (rq->iowait_pc >= 100) {
1816 + rq->iowait_pc %= 100;
1817 + cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
1818 + }
1819 + } else {
1820 + rq->idle_pc += pc;
1821 + if (rq->idle_pc >= 100) {
1822 + rq->idle_pc %= 100;
1823 + cpustat->idle = cputime64_add(cpustat->idle, tmp);
1824 + }
1825 + }
1826 +}
1827 +
1828 +static void
1829 +pc_system_time(struct rq *rq, struct task_struct *p, int hardirq_offset,
1830 + unsigned long pc, unsigned long ns)
1831 +{
1832 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1833 + cputime_t one_jiffy = jiffies_to_cputime(1);
1834 + cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
1835 + cputime64_t tmp = cputime_to_cputime64(one_jiffy);
1836 +
1837 + p->stime_pc += pc;
1838 + if (p->stime_pc >= 100) {
1839 + p->stime_pc -= 100;
1840 + p->stime = cputime_add(p->stime, one_jiffy);
1841 + p->stimescaled = cputime_add(p->stimescaled, one_jiffy_scaled);
1842 + account_group_system_time(p, one_jiffy);
1843 + acct_update_integrals(p);
1844 + }
1845 + p->se.sum_exec_runtime += ns;
1846 +
1847 + if (hardirq_count() - hardirq_offset)
1848 + rq->irq_pc += pc;
1849 + else if (softirq_count()) {
1850 + rq->softirq_pc += pc;
1851 + if (rq->softirq_pc >= 100) {
1852 + rq->softirq_pc %= 100;
1853 + cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
1854 + }
1855 + } else {
1856 + rq->system_pc += pc;
1857 + if (rq->system_pc >= 100) {
1858 + rq->system_pc %= 100;
1859 + cpustat->system = cputime64_add(cpustat->system, tmp);
1860 + }
1861 + }
1862 +}
1863 +
1864 +static void pc_user_time(struct rq *rq, struct task_struct *p,
1865 + unsigned long pc, unsigned long ns)
1866 +{
1867 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1868 + cputime_t one_jiffy = jiffies_to_cputime(1);
1869 + cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
1870 + cputime64_t tmp = cputime_to_cputime64(one_jiffy);
1871 +
1872 + p->utime_pc += pc;
1873 + if (p->utime_pc >= 100) {
1874 + p->utime_pc -= 100;
1875 + p->utime = cputime_add(p->utime, one_jiffy);
1876 + p->utimescaled = cputime_add(p->utimescaled, one_jiffy_scaled);
1877 + account_group_user_time(p, one_jiffy);
1878 + acct_update_integrals(p);
1879 + }
1880 + p->se.sum_exec_runtime += ns;
1881 +
1882 + if (TASK_NICE(p) > 0 || idleprio_task(p)) {
1883 + rq->nice_pc += pc;
1884 + if (rq->nice_pc >= 100) {
1885 + rq->nice_pc %= 100;
1886 + cpustat->nice = cputime64_add(cpustat->nice, tmp);
1887 + }
1888 + } else {
1889 + rq->user_pc += pc;
1890 + if (rq->user_pc >= 100) {
1891 + rq->user_pc %= 100;
1892 + cpustat->user = cputime64_add(cpustat->user, tmp);
1893 + }
1894 + }
1895 +}
1896 +
1897 +/* Convert nanoseconds to percentage of one tick. */
1898 +#define NS_TO_PC(NS) (NS * 100 / JIFFIES_TO_NS(1))
1899 +
1900 +/*
1901 + * This is called on clock ticks and on context switches.
1902 + * Bank in p->se.sum_exec_runtime the ns elapsed since the last tick or switch.
1903 + * CPU scheduler quota accounting is also performed here in microseconds.
1904 + * The value returned from sched_clock() occasionally gives bogus values so
1905 + * some sanity checking is required. Time is supposed to be banked all the
1906 + * time so default to half a tick to make up for when sched_clock reverts
1907 + * to just returning jiffies, and for hardware that can't do tsc.
1908 + */
1909 +static void
1910 +update_cpu_clock(struct rq *rq, struct task_struct *p, int tick)
1911 +{
1912 + long time_diff = rq->clock - p->last_ran;
1913 + long account_ns = rq->clock - rq->timekeep_clock;
1914 + struct task_struct *idle = rq->idle;
1915 + unsigned long account_pc;
1916 +
1917 + /*
1918 + * There should be less than or equal to one jiffy worth, and not
1919 + * negative/overflow. time_diff is only used for internal scheduler
1920 + * time_slice accounting.
1921 + */
1922 + if (time_diff <= 0)
1923 + time_diff = JIFFIES_TO_NS(1) / 2;
1924 + else if (time_diff > JIFFIES_TO_NS(1))
1925 + time_diff = JIFFIES_TO_NS(1);
1926 +
1927 + if (unlikely(account_ns < 0))
1928 + account_ns = 0;
1929 +
1930 + account_pc = NS_TO_PC(account_ns);
1931 +
1932 + if (tick) {
1933 + int user_tick = user_mode(get_irq_regs());
1934 +
1935 + /* Accurate tick timekeeping */
1936 + if (user_tick)
1937 + pc_user_time(rq, p, account_pc, account_ns);
1938 + else if (p != idle || (irq_count() != HARDIRQ_OFFSET))
1939 + pc_system_time(rq, p, HARDIRQ_OFFSET,
1940 + account_pc, account_ns);
1941 + else
1942 + pc_idle_time(rq, account_pc);
1943 + } else {
1944 + /* Accurate subtick timekeeping */
1945 + if (p == idle)
1946 + pc_idle_time(rq, account_pc);
1947 + else
1948 + pc_user_time(rq, p, account_pc, account_ns);
1949 + }
1950 +
1951 + /* time_slice accounting is done in usecs to avoid overflow on 32bit */
1952 + if (rq->rq_policy != SCHED_FIFO && p != idle)
1953 + rq->rq_time_slice -= time_diff / 1000;
1954 + p->last_ran = rq->timekeep_clock = rq->clock;
1955 +}
1956 +
1957 +/*
1958 + * Return any ns on the sched_clock that have not yet been accounted in
1959 + * @p in case that task is currently running.
1960 + *
1961 + * Called with task_grq_lock() held on @rq.
1962 + */
1963 +static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
1964 +{
1965 + u64 ns = 0;
1966 +
1967 + if (p == rq->curr) {
1968 + update_rq_clock(rq);
1969 + ns = rq->clock - p->last_ran;
1970 + if ((s64)ns < 0)
1971 + ns = 0;
1972 + }
1973 +
1974 + return ns;
1975 +}
1976 +
1977 +unsigned long long task_delta_exec(struct task_struct *p)
1978 +{
1979 + unsigned long flags;
1980 + struct rq *rq;
1981 + u64 ns = 0;
1982 +
1983 + rq = task_grq_lock(p, &flags);
1984 + ns = do_task_delta_exec(p, rq);
1985 + task_grq_unlock(&flags);
1986 +
1987 + return ns;
1988 +}
1989 +
1990 +/*
1991 + * Return accounted runtime for the task.
1992 + * In case the task is currently running, return the runtime plus current's
1993 + * pending runtime that have not been accounted yet.
1994 + */
1995 +unsigned long long task_sched_runtime(struct task_struct *p)
1996 +{
1997 + unsigned long flags;
1998 + struct rq *rq;
1999 + u64 ns = 0;
2000 +
2001 + rq = task_grq_lock(p, &flags);
2002 + ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
2003 + task_grq_unlock(&flags);
2004 +
2005 + return ns;
2006 +}
2007 +
2008 +/*
2009 + * Return sum_exec_runtime for the thread group.
2010 + * In case the task is currently running, return the sum plus current's
2011 + * pending runtime that have not been accounted yet.
2012 + *
2013 + * Note that the thread group might have other running tasks as well,
2014 + * so the return value not includes other pending runtime that other
2015 + * running tasks might have.
2016 + */
2017 +unsigned long long thread_group_sched_runtime(struct task_struct *p)
2018 +{
2019 + struct task_cputime totals;
2020 + unsigned long flags;
2021 + struct rq *rq;
2022 + u64 ns;
2023 +
2024 + rq = task_grq_lock(p, &flags);
2025 + thread_group_cputime(p, &totals);
2026 + ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
2027 + task_grq_unlock(&flags);
2028 +
2029 + return ns;
2030 +}
2031 +
2032 +/* Compatibility crap for removal */
2033 +void account_user_time(struct task_struct *p, cputime_t cputime,
2034 + cputime_t cputime_scaled)
2035 +{
2036 +}
2037 +
2038 +void account_idle_time(cputime_t cputime)
2039 +{
2040 +}
2041 +
2042 +/*
2043 + * Account guest cpu time to a process.
2044 + * @p: the process that the cpu time gets accounted to
2045 + * @cputime: the cpu time spent in virtual machine since the last update
2046 + * @cputime_scaled: cputime scaled by cpu frequency
2047 + */
2048 +static void account_guest_time(struct task_struct *p, cputime_t cputime,
2049 + cputime_t cputime_scaled)
2050 +{
2051 + cputime64_t tmp;
2052 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2053 +
2054 + tmp = cputime_to_cputime64(cputime);
2055 +
2056 + /* Add guest time to process. */
2057 + p->utime = cputime_add(p->utime, cputime);
2058 + p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
2059 + account_group_user_time(p, cputime);
2060 + p->gtime = cputime_add(p->gtime, cputime);
2061 +
2062 + /* Add guest time to cpustat. */
2063 + cpustat->user = cputime64_add(cpustat->user, tmp);
2064 + cpustat->guest = cputime64_add(cpustat->guest, tmp);
2065 +}
2066 +
2067 +/*
2068 + * Account system cpu time to a process.
2069 + * @p: the process that the cpu time gets accounted to
2070 + * @hardirq_offset: the offset to subtract from hardirq_count()
2071 + * @cputime: the cpu time spent in kernel space since the last update
2072 + * @cputime_scaled: cputime scaled by cpu frequency
2073 + * This is for guest only now.
2074 + */
2075 +void account_system_time(struct task_struct *p, int hardirq_offset,
2076 + cputime_t cputime, cputime_t cputime_scaled)
2077 +{
2078 +
2079 + if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
2080 + account_guest_time(p, cputime, cputime_scaled);
2081 +}
2082 +
2083 +/*
2084 + * Account for involuntary wait time.
2085 + * @steal: the cpu time spent in involuntary wait
2086 + */
2087 +void account_steal_time(cputime_t cputime)
2088 +{
2089 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2090 + cputime64_t cputime64 = cputime_to_cputime64(cputime);
2091 +
2092 + cpustat->steal = cputime64_add(cpustat->steal, cputime64);
2093 +}
2094 +
2095 +/*
2096 + * Account for idle time.
2097 + * @cputime: the cpu time spent in idle wait
2098 + */
2099 +static void account_idle_times(cputime_t cputime)
2100 +{
2101 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2102 + cputime64_t cputime64 = cputime_to_cputime64(cputime);
2103 + struct rq *rq = this_rq();
2104 +
2105 + if (atomic_read(&rq->nr_iowait) > 0)
2106 + cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
2107 + else
2108 + cpustat->idle = cputime64_add(cpustat->idle, cputime64);
2109 +}
2110 +
2111 +#ifndef CONFIG_VIRT_CPU_ACCOUNTING
2112 +
2113 +void account_process_tick(struct task_struct *p, int user_tick)
2114 +{
2115 +}
2116 +
2117 +/*
2118 + * Account multiple ticks of steal time.
2119 + * @p: the process from which the cpu time has been stolen
2120 + * @ticks: number of stolen ticks
2121 + */
2122 +void account_steal_ticks(unsigned long ticks)
2123 +{
2124 + account_steal_time(jiffies_to_cputime(ticks));
2125 +}
2126 +
2127 +/*
2128 + * Account multiple ticks of idle time.
2129 + * @ticks: number of stolen ticks
2130 + */
2131 +void account_idle_ticks(unsigned long ticks)
2132 +{
2133 + account_idle_times(jiffies_to_cputime(ticks));
2134 +}
2135 +#endif
2136 +
2137 +/*
2138 + * Functions to test for when SCHED_ISO tasks have used their allocated
2139 + * quota as real time scheduling and convert them back to SCHED_NORMAL.
2140 + * Where possible, the data is tested lockless, to avoid grabbing grq_lock
2141 + * because the occasional inaccurate result won't matter. However the
2142 + * data is only ever modified under lock.
2143 + */
2144 +static void set_iso_refractory(void)
2145 +{
2146 + grq_lock();
2147 + grq.iso_refractory = 1;
2148 + grq_unlock();
2149 +}
2150 +
2151 +static void clear_iso_refractory(void)
2152 +{
2153 + grq_lock();
2154 + grq.iso_refractory = 0;
2155 + grq_unlock();
2156 +}
2157 +
2158 +/*
2159 + * Test if SCHED_ISO tasks have run longer than their alloted period as RT
2160 + * tasks and set the refractory flag if necessary. There is 10% hysteresis
2161 + * for unsetting the flag.
2162 + */
2163 +static unsigned int test_ret_isorefractory(struct rq *rq)
2164 +{
2165 + if (likely(!grq.iso_refractory)) {
2166 + if (grq.iso_ticks / ISO_PERIOD > sched_iso_cpu)
2167 + set_iso_refractory();
2168 + } else {
2169 + if (grq.iso_ticks / ISO_PERIOD < (sched_iso_cpu * 90 / 100))
2170 + clear_iso_refractory();
2171 + }
2172 + return grq.iso_refractory;
2173 +}
2174 +
2175 +static void iso_tick(void)
2176 +{
2177 + grq_lock();
2178 + grq.iso_ticks += 100;
2179 + grq_unlock();
2180 +}
2181 +
2182 +/* No SCHED_ISO task was running so decrease rq->iso_ticks */
2183 +static inline void no_iso_tick(void)
2184 +{
2185 + if (grq.iso_ticks) {
2186 + grq_lock();
2187 + grq.iso_ticks = grq.iso_ticks * (ISO_PERIOD - 1) / ISO_PERIOD;
2188 + grq_unlock();
2189 + }
2190 +}
2191 +
2192 +static int rq_running_iso(struct rq *rq)
2193 +{
2194 + return rq->rq_prio == ISO_PRIO;
2195 +}
2196 +
2197 +/* This manages tasks that have run out of timeslice during a scheduler_tick */
2198 +static void task_running_tick(struct rq *rq)
2199 +{
2200 + struct task_struct *p;
2201 +
2202 + /*
2203 + * If a SCHED_ISO task is running we increment the iso_ticks. In
2204 + * order to prevent SCHED_ISO tasks from causing starvation in the
2205 + * presence of true RT tasks we account those as iso_ticks as well.
2206 + */
2207 + if ((rt_queue(rq) || (iso_queue(rq) && !grq.iso_refractory))) {
2208 + if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100)
2209 + iso_tick();
2210 + } else
2211 + no_iso_tick();
2212 +
2213 + if (iso_queue(rq)) {
2214 + if (unlikely(test_ret_isorefractory(rq))) {
2215 + if (rq_running_iso(rq)) {
2216 + /*
2217 + * SCHED_ISO task is running as RT and limit
2218 + * has been hit. Force it to reschedule as
2219 + * SCHED_NORMAL by zeroing its time_slice
2220 + */
2221 + rq->rq_time_slice = 0;
2222 + }
2223 + }
2224 + }
2225 +
2226 + /* SCHED_FIFO tasks never run out of timeslice. */
2227 + if (rq_idle(rq) || rq->rq_time_slice > 0 || rq->rq_policy == SCHED_FIFO)
2228 + return;
2229 +
2230 + /* p->rt.time_slice <= 0. We only modify task_struct under grq lock */
2231 + grq_lock();
2232 + p = rq->curr;
2233 + if (likely(task_running(p))) {
2234 + requeue_task(p);
2235 + set_tsk_need_resched(p);
2236 + }
2237 + grq_unlock();
2238 +}
2239 +
2240 +void wake_up_idle_cpu(int cpu);
2241 +
2242 +/*
2243 + * This function gets called by the timer code, with HZ frequency.
2244 + * We call it with interrupts disabled. The data modified is all
2245 + * local to struct rq so we don't need to grab grq lock.
2246 + */
2247 +void scheduler_tick(void)
2248 +{
2249 + int cpu = smp_processor_id();
2250 + struct rq *rq = cpu_rq(cpu);
2251 +
2252 + sched_clock_tick();
2253 + update_rq_clock(rq);
2254 + update_cpu_clock(rq, rq->curr, 1);
2255 + if (!rq_idle(rq))
2256 + task_running_tick(rq);
2257 + else {
2258 + no_iso_tick();
2259 + if (unlikely(queued_notrunning()))
2260 + set_tsk_need_resched(rq->idle);
2261 + }
2262 +}
2263 +
2264 +notrace unsigned long get_parent_ip(unsigned long addr)
2265 +{
2266 + if (in_lock_functions(addr)) {
2267 + addr = CALLER_ADDR2;
2268 + if (in_lock_functions(addr))
2269 + addr = CALLER_ADDR3;
2270 + }
2271 + return addr;
2272 +}
2273 +
2274 +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
2275 + defined(CONFIG_PREEMPT_TRACER))
2276 +void __kprobes add_preempt_count(int val)
2277 +{
2278 +#ifdef CONFIG_DEBUG_PREEMPT
2279 + /*
2280 + * Underflow?
2281 + */
2282 + if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
2283 + return;
2284 +#endif
2285 + preempt_count() += val;
2286 +#ifdef CONFIG_DEBUG_PREEMPT
2287 + /*
2288 + * Spinlock count overflowing soon?
2289 + */
2290 + DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
2291 + PREEMPT_MASK - 10);
2292 +#endif
2293 + if (preempt_count() == val)
2294 + trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2295 +}
2296 +EXPORT_SYMBOL(add_preempt_count);
2297 +
2298 +void __kprobes sub_preempt_count(int val)
2299 +{
2300 +#ifdef CONFIG_DEBUG_PREEMPT
2301 + /*
2302 + * Underflow?
2303 + */
2304 + if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
2305 + return;
2306 + /*
2307 + * Is the spinlock portion underflowing?
2308 + */
2309 + if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
2310 + !(preempt_count() & PREEMPT_MASK)))
2311 + return;
2312 +#endif
2313 +
2314 + if (preempt_count() == val)
2315 + trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2316 + preempt_count() -= val;
2317 +}
2318 +EXPORT_SYMBOL(sub_preempt_count);
2319 +#endif
2320 +
2321 +/*
2322 + * Deadline is "now" in jiffies + (offset by priority). Setting the deadline
2323 + * is the key to everything. It distributes cpu fairly amongst tasks of the
2324 + * same nice value, it proportions cpu according to nice level, it means the
2325 + * task that last woke up the longest ago has the earliest deadline, thus
2326 + * ensuring that interactive tasks get low latency on wake up.
2327 + */
2328 +static inline int prio_deadline_diff(struct task_struct *p)
2329 +{
2330 + return (pratio(p) * rr_interval * HZ / 1000 / 100) ? : 1;
2331 +}
2332 +
2333 +static inline int longest_deadline(void)
2334 +{
2335 + return (prio_ratios[39] * rr_interval * HZ / 1000 / 100);
2336 +}
2337 +
2338 +/*
2339 + * SCHED_IDLE tasks still have a deadline set, but offset by to nice +19.
2340 + * This allows nice levels to work between IDLEPRIO tasks and gives a
2341 + * deadline longer than nice +19 for when they're scheduled as SCHED_NORMAL
2342 + * tasks.
2343 + */
2344 +static inline void time_slice_expired(struct task_struct *p)
2345 +{
2346 + reset_first_time_slice(p);
2347 + p->rt.time_slice = timeslice();
2348 + p->deadline = jiffies + prio_deadline_diff(p);
2349 + if (idleprio_task(p))
2350 + p->deadline += longest_deadline();
2351 +}
2352 +
2353 +static inline void check_deadline(struct task_struct *p)
2354 +{
2355 + if (p->rt.time_slice <= 0)
2356 + time_slice_expired(p);
2357 +}
2358 +
2359 +/*
2360 + * O(n) lookup of all tasks in the global runqueue. The real brainfuck
2361 + * of lock contention and O(n). It's not really O(n) as only the queued,
2362 + * but not running tasks are scanned, and is O(n) queued in the worst case
2363 + * scenario only because the right task can be found before scanning all of
2364 + * them.
2365 + * Tasks are selected in this order:
2366 + * Real time tasks are selected purely by their static priority and in the
2367 + * order they were queued, so the lowest value idx, and the first queued task
2368 + * of that priority value is chosen.
2369 + * If no real time tasks are found, the SCHED_ISO priority is checked, and
2370 + * all SCHED_ISO tasks have the same priority value, so they're selected by
2371 + * the earliest deadline value.
2372 + * If no SCHED_ISO tasks are found, SCHED_NORMAL tasks are selected by the
2373 + * earliest deadline.
2374 + * Finally if no SCHED_NORMAL tasks are found, SCHED_IDLEPRIO tasks are
2375 + * selected by the earliest deadline.
2376 + */
2377 +static inline struct
2378 +task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle)
2379 +{
2380 + unsigned long dl, earliest_deadline = 0; /* Initialise to silence compiler */
2381 + struct task_struct *p, *edt;
2382 + unsigned int cpu = rq->cpu;
2383 + struct list_head *queue;
2384 + int idx = 0;
2385 +
2386 + edt = idle;
2387 +retry:
2388 + idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx);
2389 + if (idx >= PRIO_LIMIT)
2390 + goto out;
2391 + queue = &grq.queue[idx];
2392 + list_for_each_entry(p, queue, rt.run_list) {
2393 + /* Make sure cpu affinity is ok */
2394 + if (!cpu_isset(cpu, p->cpus_allowed))
2395 + continue;
2396 + if (idx < MAX_RT_PRIO) {
2397 + /* We found an rt task */
2398 + edt = p;
2399 + goto out_take;
2400 + }
2401 +
2402 + /*
2403 + * No rt task, select the earliest deadline task now.
2404 + * On the 1st run the 2nd condition is never used, so
2405 + * there is no need to initialise earliest_deadline
2406 + * before. Normalise all old deadlines to now.
2407 + */
2408 + if (time_before(p->deadline, jiffies))
2409 + dl = jiffies;
2410 + else
2411 + dl = p->deadline;
2412 +
2413 + if (edt == idle ||
2414 + time_before(dl, earliest_deadline)) {
2415 + earliest_deadline = dl;
2416 + edt = p;
2417 + }
2418 + }
2419 + if (edt == idle) {
2420 + if (++idx < PRIO_LIMIT)
2421 + goto retry;
2422 + goto out;
2423 + }
2424 +out_take:
2425 + take_task(rq, edt);
2426 +out:
2427 + return edt;
2428 +}
2429 +
2430 +#ifdef CONFIG_SMP
2431 +static inline void set_cpuidle_map(unsigned long cpu)
2432 +{
2433 + cpu_set(cpu, grq.cpu_idle_map);
2434 +}
2435 +
2436 +static inline void clear_cpuidle_map(unsigned long cpu)
2437 +{
2438 + cpu_clear(cpu, grq.cpu_idle_map);
2439 +}
2440 +
2441 +#else /* CONFIG_SMP */
2442 +static inline void set_cpuidle_map(unsigned long cpu)
2443 +{
2444 +}
2445 +
2446 +static inline void clear_cpuidle_map(unsigned long cpu)
2447 +{
2448 +}
2449 +#endif /* !CONFIG_SMP */
2450 +
2451 +/*
2452 + * Print scheduling while atomic bug:
2453 + */
2454 +static noinline void __schedule_bug(struct task_struct *prev)
2455 +{
2456 + struct pt_regs *regs = get_irq_regs();
2457 +
2458 + printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
2459 + prev->comm, prev->pid, preempt_count());
2460 +
2461 + debug_show_held_locks(prev);
2462 + print_modules();
2463 + if (irqs_disabled())
2464 + print_irqtrace_events(prev);
2465 +
2466 + if (regs)
2467 + show_regs(regs);
2468 + else
2469 + dump_stack();
2470 +}
2471 +
2472 +/*
2473 + * Various schedule()-time debugging checks and statistics:
2474 + */
2475 +static inline void schedule_debug(struct task_struct *prev)
2476 +{
2477 + /*
2478 + * Test if we are atomic. Since do_exit() needs to call into
2479 + * schedule() atomically, we ignore that path for now.
2480 + * Otherwise, whine if we are scheduling when we should not be.
2481 + */
2482 + if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
2483 + __schedule_bug(prev);
2484 +
2485 + profile_hit(SCHED_PROFILING, __builtin_return_address(0));
2486 +
2487 + schedstat_inc(this_rq(), sched_count);
2488 +#ifdef CONFIG_SCHEDSTATS
2489 + if (unlikely(prev->lock_depth >= 0)) {
2490 + schedstat_inc(this_rq(), bkl_count);
2491 + schedstat_inc(prev, sched_info.bkl_count);
2492 + }
2493 +#endif
2494 +}
2495 +
2496 +/*
2497 + * schedule() is the main scheduler function.
2498 + */
2499 +asmlinkage void __sched __schedule(void)
2500 +{
2501 + struct task_struct *prev, *next, *idle;
2502 + int deactivate = 0, cpu;
2503 + long *switch_count;
2504 + struct rq *rq;
2505 + u64 now;
2506 +
2507 + cpu = smp_processor_id();
2508 + rq = this_rq();
2509 + rcu_qsctr_inc(cpu);
2510 + prev = rq->curr;
2511 + switch_count = &prev->nivcsw;
2512 +
2513 + release_kernel_lock(prev);
2514 +need_resched_nonpreemptible:
2515 +
2516 + schedule_debug(prev);
2517 + idle = rq->idle;
2518 + /*
2519 + * The idle thread is not allowed to schedule!
2520 + * Remove this check after it has been exercised a bit.
2521 + */
2522 + if (unlikely(prev == idle) && prev->state != TASK_RUNNING) {
2523 + printk(KERN_ERR "bad: scheduling from the idle thread!\n");
2524 + dump_stack();
2525 + }
2526 +
2527 + grq_lock_irq();
2528 + update_rq_clock(rq);
2529 + now = rq->clock;
2530 + update_cpu_clock(rq, prev, 0);
2531 +
2532 + clear_tsk_need_resched(prev);
2533 +
2534 + if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
2535 + if (unlikely(signal_pending_state(prev->state, prev)))
2536 + prev->state = TASK_RUNNING;
2537 + else
2538 + deactivate = 1;
2539 + switch_count = &prev->nvcsw;
2540 + }
2541 +
2542 + if (prev != idle) {
2543 + /* Update all the information stored on struct rq */
2544 + prev->rt.time_slice = rq->rq_time_slice;
2545 + prev->deadline = rq->rq_deadline;
2546 + check_deadline(prev);
2547 + return_task(prev, deactivate);
2548 + }
2549 +
2550 + if (likely(queued_notrunning())) {
2551 + next = earliest_deadline_task(rq, idle);
2552 + } else {
2553 + next = idle;
2554 + schedstat_inc(rq, sched_goidle);
2555 + }
2556 +
2557 + if (next == rq->idle)
2558 + set_cpuidle_map(cpu);
2559 + else
2560 + clear_cpuidle_map(cpu);
2561 +
2562 + prefetch(next);
2563 + prefetch_stack(next);
2564 +
2565 + prev->timestamp = prev->last_ran = now;
2566 +
2567 + if (likely(prev != next)) {
2568 + rq->rq_time_slice = next->rt.time_slice;
2569 + rq->rq_deadline = next->deadline;
2570 + rq->rq_prio = next->prio;
2571 +
2572 + sched_info_switch(prev, next);
2573 + grq.nr_switches++;
2574 + next->oncpu = 1;
2575 + prev->oncpu = 0;
2576 + rq->curr = next;
2577 + ++*switch_count;
2578 +
2579 + context_switch(rq, prev, next); /* unlocks the rq */
2580 + /*
2581 + * the context switch might have flipped the stack from under
2582 + * us, hence refresh the local variables.
2583 + */
2584 + cpu = smp_processor_id();
2585 + rq = cpu_rq(cpu);
2586 + } else
2587 + grq_unlock_irq();
2588 +
2589 + if (unlikely(reacquire_kernel_lock(current) < 0))
2590 + goto need_resched_nonpreemptible;
2591 +}
2592 +
2593 +asmlinkage void __sched schedule(void)
2594 +{
2595 +need_resched:
2596 + preempt_disable();
2597 + __schedule();
2598 + preempt_enable_no_resched();
2599 + if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
2600 + goto need_resched;
2601 +}
2602 +EXPORT_SYMBOL(schedule);
2603 +
2604 +#ifdef CONFIG_SMP
2605 +int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
2606 +{
2607 + return 0;
2608 +}
2609 +#endif
2610 +
2611 +#ifdef CONFIG_PREEMPT
2612 +/*
2613 + * this is the entry point to schedule() from in-kernel preemption
2614 + * off of preempt_enable. Kernel preemptions off return from interrupt
2615 + * occur there and call schedule directly.
2616 + */
2617 +asmlinkage void __sched preempt_schedule(void)
2618 +{
2619 + struct thread_info *ti = current_thread_info();
2620 +
2621 + /*
2622 + * If there is a non-zero preempt_count or interrupts are disabled,
2623 + * we do not want to preempt the current task. Just return..
2624 + */
2625 + if (likely(ti->preempt_count || irqs_disabled()))
2626 + return;
2627 +
2628 + do {
2629 + add_preempt_count(PREEMPT_ACTIVE);
2630 + schedule();
2631 + sub_preempt_count(PREEMPT_ACTIVE);
2632 +
2633 + /*
2634 + * Check again in case we missed a preemption opportunity
2635 + * between schedule and now.
2636 + */
2637 + barrier();
2638 + } while (need_resched());
2639 +}
2640 +EXPORT_SYMBOL(preempt_schedule);
2641 +
2642 +/*
2643 + * this is the entry point to schedule() from kernel preemption
2644 + * off of irq context.
2645 + * Note, that this is called and return with irqs disabled. This will
2646 + * protect us against recursive calling from irq.
2647 + */
2648 +asmlinkage void __sched preempt_schedule_irq(void)
2649 +{
2650 + struct thread_info *ti = current_thread_info();
2651 +
2652 + /* Catch callers which need to be fixed */
2653 + BUG_ON(ti->preempt_count || !irqs_disabled());
2654 +
2655 + do {
2656 + add_preempt_count(PREEMPT_ACTIVE);
2657 + local_irq_enable();
2658 + schedule();
2659 + local_irq_disable();
2660 + sub_preempt_count(PREEMPT_ACTIVE);
2661 +
2662 + /*
2663 + * Check again in case we missed a preemption opportunity
2664 + * between schedule and now.
2665 + */
2666 + barrier();
2667 + } while (need_resched());
2668 +}
2669 +
2670 +#endif /* CONFIG_PREEMPT */
2671 +
2672 +int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
2673 + void *key)
2674 +{
2675 + return try_to_wake_up(curr->private, mode, sync);
2676 +}
2677 +EXPORT_SYMBOL(default_wake_function);
2678 +
2679 +/*
2680 + * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
2681 + * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
2682 + * number) then we wake all the non-exclusive tasks and one exclusive task.
2683 + *
2684 + * There are circumstances in which we can try to wake a task which has already
2685 + * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
2686 + * zero in this (rare) case, and we handle it by continuing to scan the queue.
2687 + */
2688 +void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
2689 + int nr_exclusive, int sync, void *key)
2690 +{
2691 + struct list_head *tmp, *next;
2692 +
2693 + list_for_each_safe(tmp, next, &q->task_list) {
2694 + wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
2695 + unsigned flags = curr->flags;
2696 +
2697 + if (curr->func(curr, mode, sync, key) &&
2698 + (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
2699 + break;
2700 + }
2701 +}
2702 +
2703 +/**
2704 + * __wake_up - wake up threads blocked on a waitqueue.
2705 + * @q: the waitqueue
2706 + * @mode: which threads
2707 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2708 + * @key: is directly passed to the wakeup function
2709 + *
2710 + * It may be assumed that this function implies a write memory barrier before
2711 + * changing the task state if and only if any tasks are woken up.
2712 + */
2713 +void __wake_up(wait_queue_head_t *q, unsigned int mode,
2714 + int nr_exclusive, void *key)
2715 +{
2716 + unsigned long flags;
2717 +
2718 + spin_lock_irqsave(&q->lock, flags);
2719 + __wake_up_common(q, mode, nr_exclusive, 0, key);
2720 + spin_unlock_irqrestore(&q->lock, flags);
2721 +}
2722 +EXPORT_SYMBOL(__wake_up);
2723 +
2724 +/*
2725 + * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
2726 + */
2727 +void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
2728 +{
2729 + __wake_up_common(q, mode, 1, 0, NULL);
2730 +}
2731 +
2732 +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
2733 +{
2734 + __wake_up_common(q, mode, 1, 0, key);
2735 +}
2736 +
2737 +/**
2738 + * __wake_up_sync_key - wake up threads blocked on a waitqueue.
2739 + * @q: the waitqueue
2740 + * @mode: which threads
2741 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2742 + * @key: opaque value to be passed to wakeup targets
2743 + *
2744 + * The sync wakeup differs that the waker knows that it will schedule
2745 + * away soon, so while the target thread will be woken up, it will not
2746 + * be migrated to another CPU - ie. the two threads are 'synchronized'
2747 + * with each other. This can prevent needless bouncing between CPUs.
2748 + *
2749 + * On UP it can prevent extra preemption.
2750 + *
2751 + * It may be assumed that this function implies a write memory barrier before
2752 + * changing the task state if and only if any tasks are woken up.
2753 + */
2754 +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
2755 + int nr_exclusive, void *key)
2756 +{
2757 + unsigned long flags;
2758 + int sync = 1;
2759 +
2760 + if (unlikely(!q))
2761 + return;
2762 +
2763 + if (unlikely(!nr_exclusive))
2764 + sync = 0;
2765 +
2766 + spin_lock_irqsave(&q->lock, flags);
2767 + __wake_up_common(q, mode, nr_exclusive, sync, key);
2768 + spin_unlock_irqrestore(&q->lock, flags);
2769 +}
2770 +EXPORT_SYMBOL_GPL(__wake_up_sync_key);
2771 +
2772 +/**
2773 + * __wake_up_sync - wake up threads blocked on a waitqueue.
2774 + * @q: the waitqueue
2775 + * @mode: which threads
2776 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2777 + *
2778 + * The sync wakeup differs that the waker knows that it will schedule
2779 + * away soon, so while the target thread will be woken up, it will not
2780 + * be migrated to another CPU - ie. the two threads are 'synchronized'
2781 + * with each other. This can prevent needless bouncing between CPUs.
2782 + *
2783 + * On UP it can prevent extra preemption.
2784 + */
2785 +void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
2786 +{
2787 + unsigned long flags;
2788 + int sync = 1;
2789 +
2790 + if (unlikely(!q))
2791 + return;
2792 +
2793 + if (unlikely(!nr_exclusive))
2794 + sync = 0;
2795 +
2796 + spin_lock_irqsave(&q->lock, flags);
2797 + __wake_up_common(q, mode, nr_exclusive, sync, NULL);
2798 + spin_unlock_irqrestore(&q->lock, flags);
2799 +}
2800 +EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
2801 +
2802 +/**
2803 + * complete: - signals a single thread waiting on this completion
2804 + * @x: holds the state of this particular completion
2805 + *
2806 + * This will wake up a single thread waiting on this completion. Threads will be
2807 + * awakened in the same order in which they were queued.
2808 + *
2809 + * See also complete_all(), wait_for_completion() and related routines.
2810 + *
2811 + * It may be assumed that this function implies a write memory barrier before
2812 + * changing the task state if and only if any tasks are woken up.
2813 + */
2814 +void complete(struct completion *x)
2815 +{
2816 + unsigned long flags;
2817 +
2818 + spin_lock_irqsave(&x->wait.lock, flags);
2819 + x->done++;
2820 + __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
2821 + spin_unlock_irqrestore(&x->wait.lock, flags);
2822 +}
2823 +EXPORT_SYMBOL(complete);
2824 +
2825 +/**
2826 + * complete_all: - signals all threads waiting on this completion
2827 + * @x: holds the state of this particular completion
2828 + *
2829 + * This will wake up all threads waiting on this particular completion event.
2830 + *
2831 + * It may be assumed that this function implies a write memory barrier before
2832 + * changing the task state if and only if any tasks are woken up.
2833 + */
2834 +void complete_all(struct completion *x)
2835 +{
2836 + unsigned long flags;
2837 +
2838 + spin_lock_irqsave(&x->wait.lock, flags);
2839 + x->done += UINT_MAX/2;
2840 + __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
2841 + spin_unlock_irqrestore(&x->wait.lock, flags);
2842 +}
2843 +EXPORT_SYMBOL(complete_all);
2844 +
2845 +static inline long __sched
2846 +do_wait_for_common(struct completion *x, long timeout, int state)
2847 +{
2848 + if (!x->done) {
2849 + DECLARE_WAITQUEUE(wait, current);
2850 +
2851 + wait.flags |= WQ_FLAG_EXCLUSIVE;
2852 + __add_wait_queue_tail(&x->wait, &wait);
2853 + do {
2854 + if (signal_pending_state(state, current)) {
2855 + timeout = -ERESTARTSYS;
2856 + break;
2857 + }
2858 + __set_current_state(state);
2859 + spin_unlock_irq(&x->wait.lock);
2860 + timeout = schedule_timeout(timeout);
2861 + spin_lock_irq(&x->wait.lock);
2862 + } while (!x->done && timeout);
2863 + __remove_wait_queue(&x->wait, &wait);
2864 + if (!x->done)
2865 + return timeout;
2866 + }
2867 + x->done--;
2868 + return timeout ?: 1;
2869 +}
2870 +
2871 +static long __sched
2872 +wait_for_common(struct completion *x, long timeout, int state)
2873 +{
2874 + might_sleep();
2875 +
2876 + spin_lock_irq(&x->wait.lock);
2877 + timeout = do_wait_for_common(x, timeout, state);
2878 + spin_unlock_irq(&x->wait.lock);
2879 + return timeout;
2880 +}
2881 +
2882 +/**
2883 + * wait_for_completion: - waits for completion of a task
2884 + * @x: holds the state of this particular completion
2885 + *
2886 + * This waits to be signaled for completion of a specific task. It is NOT
2887 + * interruptible and there is no timeout.
2888 + *
2889 + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
2890 + * and interrupt capability. Also see complete().
2891 + */
2892 +void __sched wait_for_completion(struct completion *x)
2893 +{
2894 + wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
2895 +}
2896 +EXPORT_SYMBOL(wait_for_completion);
2897 +
2898 +/**
2899 + * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
2900 + * @x: holds the state of this particular completion
2901 + * @timeout: timeout value in jiffies
2902 + *
2903 + * This waits for either a completion of a specific task to be signaled or for a
2904 + * specified timeout to expire. The timeout is in jiffies. It is not
2905 + * interruptible.
2906 + */
2907 +unsigned long __sched
2908 +wait_for_completion_timeout(struct completion *x, unsigned long timeout)
2909 +{
2910 + return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
2911 +}
2912 +EXPORT_SYMBOL(wait_for_completion_timeout);
2913 +
2914 +/**
2915 + * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
2916 + * @x: holds the state of this particular completion
2917 + *
2918 + * This waits for completion of a specific task to be signaled. It is
2919 + * interruptible.
2920 + */
2921 +int __sched wait_for_completion_interruptible(struct completion *x)
2922 +{
2923 + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
2924 + if (t == -ERESTARTSYS)
2925 + return t;
2926 + return 0;
2927 +}
2928 +EXPORT_SYMBOL(wait_for_completion_interruptible);
2929 +
2930 +/**
2931 + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
2932 + * @x: holds the state of this particular completion
2933 + * @timeout: timeout value in jiffies
2934 + *
2935 + * This waits for either a completion of a specific task to be signaled or for a
2936 + * specified timeout to expire. It is interruptible. The timeout is in jiffies.
2937 + */
2938 +unsigned long __sched
2939 +wait_for_completion_interruptible_timeout(struct completion *x,
2940 + unsigned long timeout)
2941 +{
2942 + return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
2943 +}
2944 +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
2945 +
2946 +/**
2947 + * wait_for_completion_killable: - waits for completion of a task (killable)
2948 + * @x: holds the state of this particular completion
2949 + *
2950 + * This waits to be signaled for completion of a specific task. It can be
2951 + * interrupted by a kill signal.
2952 + */
2953 +int __sched wait_for_completion_killable(struct completion *x)
2954 +{
2955 + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
2956 + if (t == -ERESTARTSYS)
2957 + return t;
2958 + return 0;
2959 +}
2960 +EXPORT_SYMBOL(wait_for_completion_killable);
2961 +
2962 +/**
2963 + * try_wait_for_completion - try to decrement a completion without blocking
2964 + * @x: completion structure
2965 + *
2966 + * Returns: 0 if a decrement cannot be done without blocking
2967 + * 1 if a decrement succeeded.
2968 + *
2969 + * If a completion is being used as a counting completion,
2970 + * attempt to decrement the counter without blocking. This
2971 + * enables us to avoid waiting if the resource the completion
2972 + * is protecting is not available.
2973 + */
2974 +bool try_wait_for_completion(struct completion *x)
2975 +{
2976 + int ret = 1;
2977 +
2978 + spin_lock_irq(&x->wait.lock);
2979 + if (!x->done)
2980 + ret = 0;
2981 + else
2982 + x->done--;
2983 + spin_unlock_irq(&x->wait.lock);
2984 + return ret;
2985 +}
2986 +EXPORT_SYMBOL(try_wait_for_completion);
2987 +
2988 +/**
2989 + * completion_done - Test to see if a completion has any waiters
2990 + * @x: completion structure
2991 + *
2992 + * Returns: 0 if there are waiters (wait_for_completion() in progress)
2993 + * 1 if there are no waiters.
2994 + *
2995 + */
2996 +bool completion_done(struct completion *x)
2997 +{
2998 + int ret = 1;
2999 +
3000 + spin_lock_irq(&x->wait.lock);
3001 + if (!x->done)
3002 + ret = 0;
3003 + spin_unlock_irq(&x->wait.lock);
3004 + return ret;
3005 +}
3006 +EXPORT_SYMBOL(completion_done);
3007 +
3008 +static long __sched
3009 +sleep_on_common(wait_queue_head_t *q, int state, long timeout)
3010 +{
3011 + unsigned long flags;
3012 + wait_queue_t wait;
3013 +
3014 + init_waitqueue_entry(&wait, current);
3015 +
3016 + __set_current_state(state);
3017 +
3018 + spin_lock_irqsave(&q->lock, flags);
3019 + __add_wait_queue(q, &wait);
3020 + spin_unlock(&q->lock);
3021 + timeout = schedule_timeout(timeout);
3022 + spin_lock_irq(&q->lock);
3023 + __remove_wait_queue(q, &wait);
3024 + spin_unlock_irqrestore(&q->lock, flags);
3025 +
3026 + return timeout;
3027 +}
3028 +
3029 +void __sched interruptible_sleep_on(wait_queue_head_t *q)
3030 +{
3031 + sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
3032 +}
3033 +EXPORT_SYMBOL(interruptible_sleep_on);
3034 +
3035 +long __sched
3036 +interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
3037 +{
3038 + return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
3039 +}
3040 +EXPORT_SYMBOL(interruptible_sleep_on_timeout);
3041 +
3042 +void __sched sleep_on(wait_queue_head_t *q)
3043 +{
3044 + sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
3045 +}
3046 +EXPORT_SYMBOL(sleep_on);
3047 +
3048 +long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
3049 +{
3050 + return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
3051 +}
3052 +EXPORT_SYMBOL(sleep_on_timeout);
3053 +
3054 +#ifdef CONFIG_RT_MUTEXES
3055 +
3056 +/*
3057 + * rt_mutex_setprio - set the current priority of a task
3058 + * @p: task
3059 + * @prio: prio value (kernel-internal form)
3060 + *
3061 + * This function changes the 'effective' priority of a task. It does
3062 + * not touch ->normal_prio like __setscheduler().
3063 + *
3064 + * Used by the rt_mutex code to implement priority inheritance logic.
3065 + */
3066 +void rt_mutex_setprio(struct task_struct *p, int prio)
3067 +{
3068 + unsigned long flags;
3069 + int queued, oldprio;
3070 + struct rq *rq;
3071 +
3072 + BUG_ON(prio < 0 || prio > MAX_PRIO);
3073 +
3074 + rq = time_task_grq_lock(p, &flags);
3075 +
3076 + oldprio = p->prio;
3077 + queued = task_queued_only(p);
3078 + if (queued)
3079 + dequeue_task(p);
3080 + p->prio = prio;
3081 + if (task_running(p) && prio > oldprio)
3082 + resched_task(p);
3083 + if (queued) {
3084 + enqueue_task(p);
3085 + try_preempt(p);
3086 + }
3087 +
3088 + task_grq_unlock(&flags);
3089 +}
3090 +
3091 +#endif
3092 +
3093 +/*
3094 + * Adjust the deadline for when the priority is to change, before it's
3095 + * changed.
3096 + */
3097 +static void adjust_deadline(struct task_struct *p, int new_prio)
3098 +{
3099 + p->deadline += (prio_ratios[USER_PRIO(new_prio)] - pratio(p)) *
3100 + rr_interval * HZ / 1000 / 100;
3101 +}
3102 +
3103 +void set_user_nice(struct task_struct *p, long nice)
3104 +{
3105 + int queued, new_static;
3106 + unsigned long flags;
3107 + struct rq *rq;
3108 +
3109 + if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
3110 + return;
3111 + new_static = NICE_TO_PRIO(nice);
3112 + /*
3113 + * We have to be careful, if called from sys_setpriority(),
3114 + * the task might be in the middle of scheduling on another CPU.
3115 + */
3116 + rq = time_task_grq_lock(p, &flags);
3117 + /*
3118 + * The RT priorities are set via sched_setscheduler(), but we still
3119 + * allow the 'normal' nice value to be set - but as expected
3120 + * it wont have any effect on scheduling until the task is
3121 + * not SCHED_NORMAL/SCHED_BATCH:
3122 + */
3123 + if (has_rt_policy(p)) {
3124 + p->static_prio = new_static;
3125 + goto out_unlock;
3126 + }
3127 + queued = task_queued_only(p);
3128 + /*
3129 + * If p is actually running, we don't need to do anything when
3130 + * changing the priority because the grq is unaffected.
3131 + */
3132 + if (queued)
3133 + dequeue_task(p);
3134 +
3135 + adjust_deadline(p, new_static);
3136 + p->static_prio = new_static;
3137 + p->prio = effective_prio(p);
3138 +
3139 + if (queued) {
3140 + enqueue_task(p);
3141 + try_preempt(p);
3142 + }
3143 +
3144 + /* Just resched the task, schedule() will know what to do. */
3145 + if (task_running(p))
3146 + resched_task(p);
3147 +out_unlock:
3148 + task_grq_unlock(&flags);
3149 +}
3150 +EXPORT_SYMBOL(set_user_nice);
3151 +
3152 +/*
3153 + * can_nice - check if a task can reduce its nice value
3154 + * @p: task
3155 + * @nice: nice value
3156 + */
3157 +int can_nice(const struct task_struct *p, const int nice)
3158 +{
3159 + /* convert nice value [19,-20] to rlimit style value [1,40] */
3160 + int nice_rlim = 20 - nice;
3161 +
3162 + return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
3163 + capable(CAP_SYS_NICE));
3164 +}
3165 +
3166 +#ifdef __ARCH_WANT_SYS_NICE
3167 +
3168 +/*
3169 + * sys_nice - change the priority of the current process.
3170 + * @increment: priority increment
3171 + *
3172 + * sys_setpriority is a more generic, but much slower function that
3173 + * does similar things.
3174 + */
3175 +SYSCALL_DEFINE1(nice, int, increment)
3176 +{
3177 + long nice, retval;
3178 +
3179 + /*
3180 + * Setpriority might change our priority at the same moment.
3181 + * We don't have to worry. Conceptually one call occurs first
3182 + * and we have a single winner.
3183 + */
3184 + if (increment < -40)
3185 + increment = -40;
3186 + if (increment > 40)
3187 + increment = 40;
3188 +
3189 + nice = TASK_NICE(current) + increment;
3190 + if (nice < -20)
3191 + nice = -20;
3192 + if (nice > 19)
3193 + nice = 19;
3194 +
3195 + if (increment < 0 && !can_nice(current, nice))
3196 + return -EPERM;
3197 +
3198 + retval = security_task_setnice(current, nice);
3199 + if (retval)
3200 + return retval;
3201 +
3202 + set_user_nice(current, nice);
3203 + return 0;
3204 +}
3205 +
3206 +#endif
3207 +
3208 +/**
3209 + * task_prio - return the priority value of a given task.
3210 + * @p: the task in question.
3211 + *
3212 + * This is the priority value as seen by users in /proc.
3213 + * RT tasks are offset by -100. Normal tasks are centered
3214 + * around 1, value goes from 0 (SCHED_ISO) up to 82 (nice +19
3215 + * SCHED_IDLE).
3216 + */
3217 +int task_prio(const struct task_struct *p)
3218 +{
3219 + int delta, prio = p->prio - MAX_RT_PRIO;
3220 +
3221 + /* rt tasks and iso tasks */
3222 + if (prio <= 0)
3223 + goto out;
3224 +
3225 + delta = (p->deadline - jiffies) * 40 / longest_deadline();
3226 + if (delta > 0 && delta <= 80)
3227 + prio += delta;
3228 +out:
3229 + return prio;
3230 +}
3231 +
3232 +/**
3233 + * task_nice - return the nice value of a given task.
3234 + * @p: the task in question.
3235 + */
3236 +int task_nice(const struct task_struct *p)
3237 +{
3238 + return TASK_NICE(p);
3239 +}
3240 +EXPORT_SYMBOL_GPL(task_nice);
3241 +
3242 +/**
3243 + * idle_cpu - is a given cpu idle currently?
3244 + * @cpu: the processor in question.
3245 + */
3246 +int idle_cpu(int cpu)
3247 +{
3248 + return cpu_curr(cpu) == cpu_rq(cpu)->idle;
3249 +}
3250 +
3251 +/**
3252 + * idle_task - return the idle task for a given cpu.
3253 + * @cpu: the processor in question.
3254 + */
3255 +struct task_struct *idle_task(int cpu)
3256 +{
3257 + return cpu_rq(cpu)->idle;
3258 +}
3259 +
3260 +/**
3261 + * find_process_by_pid - find a process with a matching PID value.
3262 + * @pid: the pid in question.
3263 + */
3264 +static inline struct task_struct *find_process_by_pid(pid_t pid)
3265 +{
3266 + return pid ? find_task_by_vpid(pid) : current;
3267 +}
3268 +
3269 +/* Actually do priority change: must hold grq lock. */
3270 +static void __setscheduler(struct task_struct *p, int policy, int prio)
3271 +{
3272 + BUG_ON(task_queued_only(p));
3273 +
3274 + p->policy = policy;
3275 + p->rt_priority = prio;
3276 + p->normal_prio = normal_prio(p);
3277 + /* we are holding p->pi_lock already */
3278 + p->prio = rt_mutex_getprio(p);
3279 + /*
3280 + * Reschedule if running. schedule() will know if it can continue
3281 + * running or not.
3282 + */
3283 + if (task_running(p))
3284 + resched_task(p);
3285 +}
3286 +
3287 +/*
3288 + * check the target process has a UID that matches the current process's
3289 + */
3290 +static bool check_same_owner(struct task_struct *p)
3291 +{
3292 + const struct cred *cred = current_cred(), *pcred;
3293 + bool match;
3294 +
3295 + rcu_read_lock();
3296 + pcred = __task_cred(p);
3297 + match = (cred->euid == pcred->euid ||
3298 + cred->euid == pcred->uid);
3299 + rcu_read_unlock();
3300 + return match;
3301 +}
3302 +
3303 +static int __sched_setscheduler(struct task_struct *p, int policy,
3304 + struct sched_param *param, bool user)
3305 +{
3306 + struct sched_param zero_param = { .sched_priority = 0 };
3307 + int queued, retval, oldprio, oldpolicy = -1;
3308 + unsigned long flags, rlim_rtprio = 0;
3309 + struct rq *rq;
3310 +
3311 + /* may grab non-irq protected spin_locks */
3312 + BUG_ON(in_interrupt());
3313 +
3314 + if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) {
3315 + unsigned long lflags;
3316 +
3317 + if (!lock_task_sighand(p, &lflags))
3318 + return -ESRCH;
3319 + rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
3320 + unlock_task_sighand(p, &lflags);
3321 + if (rlim_rtprio)
3322 + goto recheck;
3323 + /*
3324 + * If the caller requested an RT policy without having the
3325 + * necessary rights, we downgrade the policy to SCHED_ISO.
3326 + * We also set the parameter to zero to pass the checks.
3327 + */
3328 + policy = SCHED_ISO;
3329 + param = &zero_param;
3330 + }
3331 +recheck:
3332 + /* double check policy once rq lock held */
3333 + if (policy < 0)
3334 + policy = oldpolicy = p->policy;
3335 + else if (!SCHED_RANGE(policy))
3336 + return -EINVAL;
3337 + /*
3338 + * Valid priorities for SCHED_FIFO and SCHED_RR are
3339 + * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
3340 + * SCHED_BATCH is 0.
3341 + */
3342 + if (param->sched_priority < 0 ||
3343 + (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
3344 + (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
3345 + return -EINVAL;
3346 + if (is_rt_policy(policy) != (param->sched_priority != 0))
3347 + return -EINVAL;
3348 +
3349 + /*
3350 + * Allow unprivileged RT tasks to decrease priority:
3351 + */
3352 + if (user && !capable(CAP_SYS_NICE)) {
3353 + if (is_rt_policy(policy)) {
3354 + /* can't set/change the rt policy */
3355 + if (policy != p->policy && !rlim_rtprio)
3356 + return -EPERM;
3357 +
3358 + /* can't increase priority */
3359 + if (param->sched_priority > p->rt_priority &&
3360 + param->sched_priority > rlim_rtprio)
3361 + return -EPERM;
3362 + } else {
3363 + switch (p->policy) {
3364 + /*
3365 + * Can only downgrade policies but not back to
3366 + * SCHED_NORMAL
3367 + */
3368 + case SCHED_ISO:
3369 + if (policy == SCHED_ISO)
3370 + goto out;
3371 + if (policy == SCHED_NORMAL)
3372 + return -EPERM;
3373 + break;
3374 + case SCHED_BATCH:
3375 + if (policy == SCHED_BATCH)
3376 + goto out;
3377 + if (policy != SCHED_IDLE)
3378 + return -EPERM;
3379 + break;
3380 + case SCHED_IDLE:
3381 + if (policy == SCHED_IDLE)
3382 + goto out;
3383 + return -EPERM;
3384 + default:
3385 + break;
3386 + }
3387 + }
3388 +
3389 + /* can't change other user's priorities */
3390 + if (!check_same_owner(p))
3391 + return -EPERM;
3392 + }
3393 +
3394 + retval = security_task_setscheduler(p, policy, param);
3395 + if (retval)
3396 + return retval;
3397 + /*
3398 + * make sure no PI-waiters arrive (or leave) while we are
3399 + * changing the priority of the task:
3400 + */
3401 + spin_lock_irqsave(&p->pi_lock, flags);
3402 + /*
3403 + * To be able to change p->policy safely, the apropriate
3404 + * runqueue lock must be held.
3405 + */
3406 + rq = __task_grq_lock(p);
3407 + /* recheck policy now with rq lock held */
3408 + if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
3409 + __task_grq_unlock();
3410 + spin_unlock_irqrestore(&p->pi_lock, flags);
3411 + policy = oldpolicy = -1;
3412 + goto recheck;
3413 + }
3414 + update_rq_clock(rq);
3415 + queued = task_queued_only(p);
3416 + if (queued)
3417 + dequeue_task(p);
3418 + oldprio = p->prio;
3419 + __setscheduler(p, policy, param->sched_priority);
3420 + if (queued) {
3421 + enqueue_task(p);
3422 + try_preempt(p);
3423 + }
3424 + __task_grq_unlock();
3425 + spin_unlock_irqrestore(&p->pi_lock, flags);
3426 +
3427 + rt_mutex_adjust_pi(p);
3428 +out:
3429 + return 0;
3430 +}
3431 +
3432 +/**
3433 + * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
3434 + * @p: the task in question.
3435 + * @policy: new policy.
3436 + * @param: structure containing the new RT priority.
3437 + *
3438 + * NOTE that the task may be already dead.
3439 + */
3440 +int sched_setscheduler(struct task_struct *p, int policy,
3441 + struct sched_param *param)
3442 +{
3443 + return __sched_setscheduler(p, policy, param, true);
3444 +}
3445 +
3446 +EXPORT_SYMBOL_GPL(sched_setscheduler);
3447 +
3448 +/**
3449 + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
3450 + * @p: the task in question.
3451 + * @policy: new policy.
3452 + * @param: structure containing the new RT priority.
3453 + *
3454 + * Just like sched_setscheduler, only don't bother checking if the
3455 + * current context has permission. For example, this is needed in
3456 + * stop_machine(): we create temporary high priority worker threads,
3457 + * but our caller might not have that capability.
3458 + */
3459 +int sched_setscheduler_nocheck(struct task_struct *p, int policy,
3460 + struct sched_param *param)
3461 +{
3462 + return __sched_setscheduler(p, policy, param, false);
3463 +}
3464 +
3465 +static int
3466 +do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
3467 +{
3468 + struct sched_param lparam;
3469 + struct task_struct *p;
3470 + int retval;
3471 +
3472 + if (!param || pid < 0)
3473 + return -EINVAL;
3474 + if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
3475 + return -EFAULT;
3476 +
3477 + rcu_read_lock();
3478 + retval = -ESRCH;
3479 + p = find_process_by_pid(pid);
3480 + if (p != NULL)
3481 + retval = sched_setscheduler(p, policy, &lparam);
3482 + rcu_read_unlock();
3483 +
3484 + return retval;
3485 +}
3486 +
3487 +/**
3488 + * sys_sched_setscheduler - set/change the scheduler policy and RT priority
3489 + * @pid: the pid in question.
3490 + * @policy: new policy.
3491 + * @param: structure containing the new RT priority.
3492 + */
3493 +asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
3494 + struct sched_param __user *param)
3495 +{
3496 + /* negative values for policy are not valid */
3497 + if (policy < 0)
3498 + return -EINVAL;
3499 +
3500 + return do_sched_setscheduler(pid, policy, param);
3501 +}
3502 +
3503 +/**
3504 + * sys_sched_setparam - set/change the RT priority of a thread
3505 + * @pid: the pid in question.
3506 + * @param: structure containing the new RT priority.
3507 + */
3508 +SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
3509 +{
3510 + return do_sched_setscheduler(pid, -1, param);
3511 +}
3512 +
3513 +/**
3514 + * sys_sched_getscheduler - get the policy (scheduling class) of a thread
3515 + * @pid: the pid in question.
3516 + */
3517 +SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
3518 +{
3519 + struct task_struct *p;
3520 + int retval = -EINVAL;
3521 +
3522 + if (pid < 0)
3523 + goto out_nounlock;
3524 +
3525 + retval = -ESRCH;
3526 + read_lock(&tasklist_lock);
3527 + p = find_process_by_pid(pid);
3528 + if (p) {
3529 + retval = security_task_getscheduler(p);
3530 + if (!retval)
3531 + retval = p->policy;
3532 + }
3533 + read_unlock(&tasklist_lock);
3534 +
3535 +out_nounlock:
3536 + return retval;
3537 +}
3538 +
3539 +/**
3540 + * sys_sched_getscheduler - get the RT priority of a thread
3541 + * @pid: the pid in question.
3542 + * @param: structure containing the RT priority.
3543 + */
3544 +SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
3545 +{
3546 + struct sched_param lp;
3547 + struct task_struct *p;
3548 + int retval = -EINVAL;
3549 +
3550 + if (!param || pid < 0)
3551 + goto out_nounlock;
3552 +
3553 + read_lock(&tasklist_lock);
3554 + p = find_process_by_pid(pid);
3555 + retval = -ESRCH;
3556 + if (!p)
3557 + goto out_unlock;
3558 +
3559 + retval = security_task_getscheduler(p);
3560 + if (retval)
3561 + goto out_unlock;
3562 +
3563 + lp.sched_priority = p->rt_priority;
3564 + read_unlock(&tasklist_lock);
3565 +
3566 + /*
3567 + * This one might sleep, we cannot do it with a spinlock held ...
3568 + */
3569 + retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
3570 +
3571 +out_nounlock:
3572 + return retval;
3573 +
3574 +out_unlock:
3575 + read_unlock(&tasklist_lock);
3576 + return retval;
3577 +}
3578 +
3579 +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
3580 +{
3581 + cpumask_var_t cpus_allowed, new_mask;
3582 + struct task_struct *p;
3583 + int retval;
3584 +
3585 + get_online_cpus();
3586 + read_lock(&tasklist_lock);
3587 +
3588 + p = find_process_by_pid(pid);
3589 + if (!p) {
3590 + read_unlock(&tasklist_lock);
3591 + put_online_cpus();
3592 + return -ESRCH;
3593 + }
3594 +
3595 + /*
3596 + * It is not safe to call set_cpus_allowed with the
3597 + * tasklist_lock held. We will bump the task_struct's
3598 + * usage count and then drop tasklist_lock.
3599 + */
3600 + get_task_struct(p);
3601 + read_unlock(&tasklist_lock);
3602 +
3603 + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
3604 + retval = -ENOMEM;
3605 + goto out_put_task;
3606 + }
3607 + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
3608 + retval = -ENOMEM;
3609 + goto out_free_cpus_allowed;
3610 + }
3611 + retval = -EPERM;
3612 + if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
3613 + goto out_unlock;
3614 +
3615 + retval = security_task_setscheduler(p, 0, NULL);
3616 + if (retval)
3617 + goto out_unlock;
3618 +
3619 + cpuset_cpus_allowed(p, cpus_allowed);
3620 + cpumask_and(new_mask, in_mask, cpus_allowed);
3621 +again:
3622 + retval = set_cpus_allowed_ptr(p, new_mask);
3623 +
3624 + if (!retval) {
3625 + cpuset_cpus_allowed(p, cpus_allowed);
3626 + if (!cpumask_subset(new_mask, cpus_allowed)) {
3627 + /*
3628 + * We must have raced with a concurrent cpuset
3629 + * update. Just reset the cpus_allowed to the
3630 + * cpuset's cpus_allowed
3631 + */
3632 + cpumask_copy(new_mask, cpus_allowed);
3633 + goto again;
3634 + }
3635 + }
3636 +out_unlock:
3637 + free_cpumask_var(new_mask);
3638 +out_free_cpus_allowed:
3639 + free_cpumask_var(cpus_allowed);
3640 +out_put_task:
3641 + put_task_struct(p);
3642 + put_online_cpus();
3643 + return retval;
3644 +}
3645 +
3646 +static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
3647 + cpumask_t *new_mask)
3648 +{
3649 + if (len < sizeof(cpumask_t)) {
3650 + memset(new_mask, 0, sizeof(cpumask_t));
3651 + } else if (len > sizeof(cpumask_t)) {
3652 + len = sizeof(cpumask_t);
3653 + }
3654 + return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
3655 +}
3656 +
3657 +
3658 +/**
3659 + * sys_sched_setaffinity - set the cpu affinity of a process
3660 + * @pid: pid of the process
3661 + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
3662 + * @user_mask_ptr: user-space pointer to the new cpu mask
3663 + */
3664 +SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
3665 + unsigned long __user *, user_mask_ptr)
3666 +{
3667 + cpumask_var_t new_mask;
3668 + int retval;
3669 +
3670 + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
3671 + return -ENOMEM;
3672 +
3673 + retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
3674 + if (retval == 0)
3675 + retval = sched_setaffinity(pid, new_mask);
3676 + free_cpumask_var(new_mask);
3677 + return retval;
3678 +}
3679 +
3680 +long sched_getaffinity(pid_t pid, cpumask_t *mask)
3681 +{
3682 + struct task_struct *p;
3683 + int retval;
3684 +
3685 + mutex_lock(&sched_hotcpu_mutex);
3686 + read_lock(&tasklist_lock);
3687 +
3688 + retval = -ESRCH;
3689 + p = find_process_by_pid(pid);
3690 + if (!p)
3691 + goto out_unlock;
3692 +
3693 + retval = security_task_getscheduler(p);
3694 + if (retval)
3695 + goto out_unlock;
3696 +
3697 + cpus_and(*mask, p->cpus_allowed, cpu_online_map);
3698 +
3699 +out_unlock:
3700 + read_unlock(&tasklist_lock);
3701 + mutex_unlock(&sched_hotcpu_mutex);
3702 + if (retval)
3703 + return retval;
3704 +
3705 + return 0;
3706 +}
3707 +
3708 +/**
3709 + * sys_sched_getaffinity - get the cpu affinity of a process
3710 + * @pid: pid of the process
3711 + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
3712 + * @user_mask_ptr: user-space pointer to hold the current cpu mask
3713 + */
3714 +SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
3715 + unsigned long __user *, user_mask_ptr)
3716 +{
3717 + int ret;
3718 + cpumask_var_t mask;
3719 +
3720 + if (len < cpumask_size())
3721 + return -EINVAL;
3722 +
3723 + if (!alloc_cpumask_var(&mask, GFP_KERNEL))
3724 + return -ENOMEM;
3725 +
3726 + ret = sched_getaffinity(pid, mask);
3727 + if (ret == 0) {
3728 + if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
3729 + ret = -EFAULT;
3730 + else
3731 + ret = cpumask_size();
3732 + }
3733 + free_cpumask_var(mask);
3734 +
3735 + return ret;
3736 +}
3737 +
3738 +/**
3739 + * sys_sched_yield - yield the current processor to other threads.
3740 + *
3741 + * This function yields the current CPU to other tasks. It does this by
3742 + * refilling the timeslice, resetting the deadline and scheduling away.
3743 + */
3744 +SYSCALL_DEFINE0(sched_yield)
3745 +{
3746 + struct task_struct *p;
3747 +
3748 + grq_lock_irq();
3749 + p = current;
3750 + schedstat_inc(this_rq(), yld_count);
3751 + update_rq_clock(task_rq(p));
3752 + time_slice_expired(p);
3753 + requeue_task(p);
3754 +
3755 + /*
3756 + * Since we are going to call schedule() anyway, there's
3757 + * no need to preempt or enable interrupts:
3758 + */
3759 + __release(grq.lock);
3760 + spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
3761 + _raw_spin_unlock(&grq.lock);
3762 + preempt_enable_no_resched();
3763 +
3764 + schedule();
3765 +
3766 + return 0;
3767 +}
3768 +
3769 +static inline int should_resched(void)
3770 +{
3771 + return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
3772 +}
3773 +
3774 +static void __cond_resched(void)
3775 +{
3776 +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
3777 + __might_sleep(__FILE__, __LINE__);
3778 +#endif
3779 + /*
3780 + * The BKS might be reacquired before we have dropped
3781 + * PREEMPT_ACTIVE, which could trigger a second
3782 + * cond_resched() call.
3783 + */
3784 + do {
3785 + add_preempt_count(PREEMPT_ACTIVE);
3786 + schedule();
3787 + sub_preempt_count(PREEMPT_ACTIVE);
3788 + } while (need_resched());
3789 +}
3790 +
3791 +int __sched _cond_resched(void)
3792 +{
3793 + if (should_resched()) {
3794 + __cond_resched();
3795 + return 1;
3796 + }
3797 + return 0;
3798 +}
3799 +EXPORT_SYMBOL(_cond_resched);
3800 +
3801 +/*
3802 + * cond_resched_lock() - if a reschedule is pending, drop the given lock,
3803 + * call schedule, and on return reacquire the lock.
3804 + *
3805 + * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
3806 + * operations here to prevent schedule() from being called twice (once via
3807 + * spin_unlock(), once by hand).
3808 + */
3809 +int cond_resched_lock(spinlock_t *lock)
3810 +{
3811 + int resched = should_resched();
3812 + int ret = 0;
3813 +
3814 + if (spin_needbreak(lock) || resched) {
3815 + spin_unlock(lock);
3816 + if (resched)
3817 + __cond_resched();
3818 + else
3819 + cpu_relax();
3820 + ret = 1;
3821 + spin_lock(lock);
3822 + }
3823 + return ret;
3824 +}
3825 +EXPORT_SYMBOL(cond_resched_lock);
3826 +
3827 +int __sched cond_resched_softirq(void)
3828 +{
3829 + BUG_ON(!in_softirq());
3830 +
3831 + if (should_resched()) {
3832 + local_bh_enable();
3833 + __cond_resched();
3834 + local_bh_disable();
3835 + return 1;
3836 + }
3837 + return 0;
3838 +}
3839 +EXPORT_SYMBOL(cond_resched_softirq);
3840 +
3841 +/**
3842 + * yield - yield the current processor to other threads.
3843 + *
3844 + * This is a shortcut for kernel-space yielding - it marks the
3845 + * thread runnable and calls sys_sched_yield().
3846 + */
3847 +void __sched yield(void)
3848 +{
3849 + set_current_state(TASK_RUNNING);
3850 + sys_sched_yield();
3851 +}
3852 +EXPORT_SYMBOL(yield);
3853 +
3854 +/*
3855 + * This task is about to go to sleep on IO. Increment rq->nr_iowait so
3856 + * that process accounting knows that this is a task in IO wait state.
3857 + *
3858 + * But don't do that if it is a deliberate, throttling IO wait (this task
3859 + * has set its backing_dev_info: the queue against which it should throttle)
3860 + */
3861 +void __sched io_schedule(void)
3862 +{
3863 + struct rq *rq = &__raw_get_cpu_var(runqueues);
3864 +
3865 + delayacct_blkio_start();
3866 + atomic_inc(&rq->nr_iowait);
3867 + schedule();
3868 + atomic_dec(&rq->nr_iowait);
3869 + delayacct_blkio_end();
3870 +}
3871 +EXPORT_SYMBOL(io_schedule);
3872 +
3873 +long __sched io_schedule_timeout(long timeout)
3874 +{
3875 + struct rq *rq = &__raw_get_cpu_var(runqueues);
3876 + long ret;
3877 +
3878 + delayacct_blkio_start();
3879 + atomic_inc(&rq->nr_iowait);
3880 + ret = schedule_timeout(timeout);
3881 + atomic_dec(&rq->nr_iowait);
3882 + delayacct_blkio_end();
3883 + return ret;
3884 +}
3885 +
3886 +/**
3887 + * sys_sched_get_priority_max - return maximum RT priority.
3888 + * @policy: scheduling class.
3889 + *
3890 + * this syscall returns the maximum rt_priority that can be used
3891 + * by a given scheduling class.
3892 + */
3893 +SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
3894 +{
3895 + int ret = -EINVAL;
3896 +
3897 + switch (policy) {
3898 + case SCHED_FIFO:
3899 + case SCHED_RR:
3900 + ret = MAX_USER_RT_PRIO-1;
3901 + break;
3902 + case SCHED_NORMAL:
3903 + case SCHED_BATCH:
3904 + case SCHED_ISO:
3905 + case SCHED_IDLE:
3906 + ret = 0;
3907 + break;
3908 + }
3909 + return ret;
3910 +}
3911 +
3912 +/**
3913 + * sys_sched_get_priority_min - return minimum RT priority.
3914 + * @policy: scheduling class.
3915 + *
3916 + * this syscall returns the minimum rt_priority that can be used
3917 + * by a given scheduling class.
3918 + */
3919 +SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
3920 +{
3921 + int ret = -EINVAL;
3922 +
3923 + switch (policy) {
3924 + case SCHED_FIFO:
3925 + case SCHED_RR:
3926 + ret = 1;
3927 + break;
3928 + case SCHED_NORMAL:
3929 + case SCHED_BATCH:
3930 + case SCHED_ISO:
3931 + case SCHED_IDLE:
3932 + ret = 0;
3933 + break;
3934 + }
3935 + return ret;
3936 +}
3937 +
3938 +/**
3939 + * sys_sched_rr_get_interval - return the default timeslice of a process.
3940 + * @pid: pid of the process.
3941 + * @interval: userspace pointer to the timeslice value.
3942 + *
3943 + * this syscall writes the default timeslice value of a given process
3944 + * into the user-space timespec buffer. A value of '0' means infinity.
3945 + */
3946 +SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
3947 + struct timespec __user *, interval)
3948 +{
3949 + struct task_struct *p;
3950 + int retval = -EINVAL;
3951 + struct timespec t;
3952 +
3953 + if (pid < 0)
3954 + goto out_nounlock;
3955 +
3956 + retval = -ESRCH;
3957 + read_lock(&tasklist_lock);
3958 + p = find_process_by_pid(pid);
3959 + if (!p)
3960 + goto out_unlock;
3961 +
3962 + retval = security_task_getscheduler(p);
3963 + if (retval)
3964 + goto out_unlock;
3965 +
3966 + t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
3967 + MS_TO_NS(task_timeslice(p)));
3968 + read_unlock(&tasklist_lock);
3969 + retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
3970 +out_nounlock:
3971 + return retval;
3972 +out_unlock:
3973 + read_unlock(&tasklist_lock);
3974 + return retval;
3975 +}
3976 +
3977 +static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
3978 +
3979 +void sched_show_task(struct task_struct *p)
3980 +{
3981 + unsigned long free = 0;
3982 + unsigned state;
3983 +
3984 + state = p->state ? __ffs(p->state) + 1 : 0;
3985 + printk(KERN_INFO "%-13.13s %c", p->comm,
3986 + state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
3987 +#if BITS_PER_LONG == 32
3988 + if (state == TASK_RUNNING)
3989 + printk(KERN_CONT " running ");
3990 + else
3991 + printk(KERN_CONT " %08lx ", thread_saved_pc(p));
3992 +#else
3993 + if (state == TASK_RUNNING)
3994 + printk(KERN_CONT " running task ");
3995 + else
3996 + printk(KERN_CONT " %016lx ", thread_saved_pc(p));
3997 +#endif
3998 +#ifdef CONFIG_DEBUG_STACK_USAGE
3999 + free = stack_not_used(p);
4000 +#endif
4001 + printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
4002 + task_pid_nr(p), task_pid_nr(p->real_parent),
4003 + (unsigned long)task_thread_info(p)->flags);
4004 +
4005 + show_stack(p, NULL);
4006 +}
4007 +
4008 +void show_state_filter(unsigned long state_filter)
4009 +{
4010 + struct task_struct *g, *p;
4011 +
4012 +#if BITS_PER_LONG == 32
4013 + printk(KERN_INFO
4014 + " task PC stack pid father\n");
4015 +#else
4016 + printk(KERN_INFO
4017 + " task PC stack pid father\n");
4018 +#endif
4019 + read_lock(&tasklist_lock);
4020 + do_each_thread(g, p) {
4021 + /*
4022 + * reset the NMI-timeout, listing all files on a slow
4023 + * console might take alot of time:
4024 + */
4025 + touch_nmi_watchdog();
4026 + if (!state_filter || (p->state & state_filter))
4027 + sched_show_task(p);
4028 + } while_each_thread(g, p);
4029 +
4030 + touch_all_softlockup_watchdogs();
4031 +
4032 + read_unlock(&tasklist_lock);
4033 + /*
4034 + * Only show locks if all tasks are dumped:
4035 + */
4036 + if (state_filter == -1)
4037 + debug_show_all_locks();
4038 +}
4039 +
4040 +/**
4041 + * init_idle - set up an idle thread for a given CPU
4042 + * @idle: task in question
4043 + * @cpu: cpu the idle task belongs to
4044 + *
4045 + * NOTE: this function does not set the idle thread's NEED_RESCHED
4046 + * flag, to make booting more robust.
4047 + */
4048 +void __cpuinit init_idle(struct task_struct *idle, int cpu)
4049 +{
4050 + struct rq *rq = cpu_rq(cpu);
4051 + unsigned long flags;
4052 +
4053 + time_grq_lock(rq, &flags);
4054 + idle->timestamp = idle->last_ran = rq->clock;
4055 + idle->state = TASK_RUNNING;
4056 + /* Setting prio to illegal value shouldn't matter when never queued */
4057 + idle->prio = rq->rq_prio = PRIO_LIMIT;
4058 + rq->rq_deadline = idle->deadline;
4059 + rq->rq_policy = idle->policy;
4060 + rq->rq_time_slice = idle->rt.time_slice;
4061 + idle->cpus_allowed = cpumask_of_cpu(cpu);
4062 + set_task_cpu(idle, cpu);
4063 + rq->curr = rq->idle = idle;
4064 + idle->oncpu = 1;
4065 + set_cpuidle_map(cpu);
4066 +#ifdef CONFIG_HOTPLUG_CPU
4067 + idle->unplugged_mask = CPU_MASK_NONE;
4068 +#endif
4069 + grq_unlock_irqrestore(&flags);
4070 +
4071 + /* Set the preempt count _outside_ the spinlocks! */
4072 +#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
4073 + task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
4074 +#else
4075 + task_thread_info(idle)->preempt_count = 0;
4076 +#endif
4077 + ftrace_graph_init_task(idle);
4078 +}
4079 +
4080 +/*
4081 + * In a system that switches off the HZ timer nohz_cpu_mask
4082 + * indicates which cpus entered this state. This is used
4083 + * in the rcu update to wait only for active cpus. For system
4084 + * which do not switch off the HZ timer nohz_cpu_mask should
4085 + * always be CPU_BITS_NONE.
4086 + */
4087 +cpumask_var_t nohz_cpu_mask;
4088 +
4089 +#ifdef CONFIG_SMP
4090 +#ifdef CONFIG_NO_HZ
4091 +static struct {
4092 + atomic_t load_balancer;
4093 + cpumask_var_t cpu_mask;
4094 + cpumask_var_t ilb_grp_nohz_mask;
4095 +} nohz ____cacheline_aligned = {
4096 + .load_balancer = ATOMIC_INIT(-1),
4097 +};
4098 +
4099 +int get_nohz_load_balancer(void)
4100 +{
4101 + return atomic_read(&nohz.load_balancer);
4102 +}
4103 +
4104 +/*
4105 + * This routine will try to nominate the ilb (idle load balancing)
4106 + * owner among the cpus whose ticks are stopped. ilb owner will do the idle
4107 + * load balancing on behalf of all those cpus. If all the cpus in the system
4108 + * go into this tickless mode, then there will be no ilb owner (as there is
4109 + * no need for one) and all the cpus will sleep till the next wakeup event
4110 + * arrives...
4111 + *
4112 + * For the ilb owner, tick is not stopped. And this tick will be used
4113 + * for idle load balancing. ilb owner will still be part of
4114 + * nohz.cpu_mask..
4115 + *
4116 + * While stopping the tick, this cpu will become the ilb owner if there
4117 + * is no other owner. And will be the owner till that cpu becomes busy
4118 + * or if all cpus in the system stop their ticks at which point
4119 + * there is no need for ilb owner.
4120 + *
4121 + * When the ilb owner becomes busy, it nominates another owner, during the
4122 + * next busy scheduler_tick()
4123 + */
4124 +int select_nohz_load_balancer(int stop_tick)
4125 +{
4126 + int cpu = smp_processor_id();
4127 +
4128 + if (stop_tick) {
4129 + cpu_rq(cpu)->in_nohz_recently = 1;
4130 +
4131 + if (!cpu_active(cpu)) {
4132 + if (atomic_read(&nohz.load_balancer) != cpu)
4133 + return 0;
4134 +
4135 + /*
4136 + * If we are going offline and still the leader,
4137 + * give up!
4138 + */
4139 + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
4140 + BUG();
4141 +
4142 + return 0;
4143 + }
4144 +
4145 + cpumask_set_cpu(cpu, nohz.cpu_mask);
4146 +
4147 + /* time for ilb owner also to sleep */
4148 + if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
4149 + if (atomic_read(&nohz.load_balancer) == cpu)
4150 + atomic_set(&nohz.load_balancer, -1);
4151 + return 0;
4152 + }
4153 +
4154 + if (atomic_read(&nohz.load_balancer) == -1) {
4155 + /* make me the ilb owner */
4156 + if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
4157 + return 1;
4158 + } else if (atomic_read(&nohz.load_balancer) == cpu)
4159 + return 1;
4160 + } else {
4161 + if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
4162 + return 0;
4163 +
4164 + cpumask_clear_cpu(cpu, nohz.cpu_mask);
4165 +
4166 + if (atomic_read(&nohz.load_balancer) == cpu)
4167 + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
4168 + BUG();
4169 + }
4170 + return 0;
4171 +}
4172 +
4173 +/*
4174 + * When add_timer_on() enqueues a timer into the timer wheel of an
4175 + * idle CPU then this timer might expire before the next timer event
4176 + * which is scheduled to wake up that CPU. In case of a completely
4177 + * idle system the next event might even be infinite time into the
4178 + * future. wake_up_idle_cpu() ensures that the CPU is woken up and
4179 + * leaves the inner idle loop so the newly added timer is taken into
4180 + * account when the CPU goes back to idle and evaluates the timer
4181 + * wheel for the next timer event.
4182 + */
4183 +void wake_up_idle_cpu(int cpu)
4184 +{
4185 + struct task_struct *idle;
4186 + struct rq *rq;
4187 +
4188 + if (cpu == smp_processor_id())
4189 + return;
4190 +
4191 + rq = cpu_rq(cpu);
4192 + idle = rq->idle;
4193 +
4194 + /*
4195 + * This is safe, as this function is called with the timer
4196 + * wheel base lock of (cpu) held. When the CPU is on the way
4197 + * to idle and has not yet set rq->curr to idle then it will
4198 + * be serialized on the timer wheel base lock and take the new
4199 + * timer into account automatically.
4200 + */
4201 + if (unlikely(rq->curr != idle))
4202 + return;
4203 +
4204 + /*
4205 + * We can set TIF_RESCHED on the idle task of the other CPU
4206 + * lockless. The worst case is that the other CPU runs the
4207 + * idle task through an additional NOOP schedule()
4208 + */
4209 + set_tsk_need_resched(idle);
4210 +
4211 + /* NEED_RESCHED must be visible before we test polling */
4212 + smp_mb();
4213 + if (!tsk_is_polling(idle))
4214 + smp_send_reschedule(cpu);
4215 +}
4216 +
4217 +#endif /* CONFIG_NO_HZ */
4218 +
4219 +/*
4220 + * Change a given task's CPU affinity. Migrate the thread to a
4221 + * proper CPU and schedule it away if the CPU it's executing on
4222 + * is removed from the allowed bitmask.
4223 + *
4224 + * NOTE: the caller must have a valid reference to the task, the
4225 + * task must not exit() & deallocate itself prematurely. The
4226 + * call is not atomic; no spinlocks may be held.
4227 + */
4228 +int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
4229 +{
4230 + unsigned long flags;
4231 + int running = 0;
4232 + int queued = 0;
4233 + struct rq *rq;
4234 + int ret = 0;
4235 +
4236 + rq = task_grq_lock(p, &flags);
4237 + if (!cpumask_intersects(new_mask, cpu_online_mask)) {
4238 + ret = -EINVAL;
4239 + goto out;
4240 + }
4241 +
4242 + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
4243 + !cpumask_equal(&p->cpus_allowed, new_mask))) {
4244 + ret = -EINVAL;
4245 + goto out;
4246 + }
4247 +
4248 + queued = task_queued_only(p);
4249 +
4250 + cpumask_copy(&p->cpus_allowed, new_mask);
4251 + p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
4252 +
4253 + /* Can the task run on the task's current CPU? If so, we're done */
4254 + if (cpumask_test_cpu(task_cpu(p), new_mask))
4255 + goto out;
4256 +
4257 + /* Reschedule the task, schedule() will know if it can keep running */
4258 + if (task_running(p))
4259 + running = 1;
4260 + else
4261 + set_task_cpu(p, cpumask_any_and(cpu_online_mask, new_mask));
4262 +
4263 +out:
4264 + if (queued)
4265 + try_preempt(p);
4266 + task_grq_unlock(&flags);
4267 +
4268 + /* This might be a flaky way of changing cpus! */
4269 + if (running)
4270 + schedule();
4271 + return ret;
4272 +}
4273 +EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
4274 +
4275 +#ifdef CONFIG_HOTPLUG_CPU
4276 +/* Schedules idle task to be the next runnable task on current CPU.
4277 + * It does so by boosting its priority to highest possible.
4278 + * Used by CPU offline code.
4279 + */
4280 +void sched_idle_next(void)
4281 +{
4282 + int this_cpu = smp_processor_id();
4283 + struct rq *rq = cpu_rq(this_cpu);
4284 + struct task_struct *idle = rq->idle;
4285 + unsigned long flags;
4286 +
4287 + /* cpu has to be offline */
4288 + BUG_ON(cpu_online(this_cpu));
4289 +
4290 + /*
4291 + * Strictly not necessary since rest of the CPUs are stopped by now
4292 + * and interrupts disabled on the current cpu.
4293 + */
4294 + time_grq_lock(rq, &flags);
4295 +
4296 + __setscheduler(idle, SCHED_FIFO, MAX_RT_PRIO - 1);
4297 +
4298 + activate_idle_task(idle);
4299 + set_tsk_need_resched(rq->curr);
4300 +
4301 + grq_unlock_irqrestore(&flags);
4302 +}
4303 +
4304 +/*
4305 + * Ensures that the idle task is using init_mm right before its cpu goes
4306 + * offline.
4307 + */
4308 +void idle_task_exit(void)
4309 +{
4310 + struct mm_struct *mm = current->active_mm;
4311 +
4312 + BUG_ON(cpu_online(smp_processor_id()));
4313 +
4314 + if (mm != &init_mm)
4315 + switch_mm(mm, &init_mm, current);
4316 + mmdrop(mm);
4317 +}
4318 +
4319 +#endif /* CONFIG_HOTPLUG_CPU */
4320 +
4321 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
4322 +
4323 +static struct ctl_table sd_ctl_dir[] = {
4324 + {
4325 + .procname = "sched_domain",
4326 + .mode = 0555,
4327 + },
4328 + {0, },
4329 +};
4330 +
4331 +static struct ctl_table sd_ctl_root[] = {
4332 + {
4333 + .ctl_name = CTL_KERN,
4334 + .procname = "kernel",
4335 + .mode = 0555,
4336 + .child = sd_ctl_dir,
4337 + },
4338 + {0, },
4339 +};
4340 +
4341 +static struct ctl_table *sd_alloc_ctl_entry(int n)
4342 +{
4343 + struct ctl_table *entry =
4344 + kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
4345 +
4346 + return entry;
4347 +}
4348 +
4349 +static void sd_free_ctl_entry(struct ctl_table **tablep)
4350 +{
4351 + struct ctl_table *entry;
4352 +
4353 + /*
4354 + * In the intermediate directories, both the child directory and
4355 + * procname are dynamically allocated and could fail but the mode
4356 + * will always be set. In the lowest directory the names are
4357 + * static strings and all have proc handlers.
4358 + */
4359 + for (entry = *tablep; entry->mode; entry++) {
4360 + if (entry->child)
4361 + sd_free_ctl_entry(&entry->child);
4362 + if (entry->proc_handler == NULL)
4363 + kfree(entry->procname);
4364 + }
4365 +
4366 + kfree(*tablep);
4367 + *tablep = NULL;
4368 +}
4369 +
4370 +static void
4371 +set_table_entry(struct ctl_table *entry,
4372 + const char *procname, void *data, int maxlen,
4373 + mode_t mode, proc_handler *proc_handler)
4374 +{
4375 + entry->procname = procname;
4376 + entry->data = data;
4377 + entry->maxlen = maxlen;
4378 + entry->mode = mode;
4379 + entry->proc_handler = proc_handler;
4380 +}
4381 +
4382 +static struct ctl_table *
4383 +sd_alloc_ctl_domain_table(struct sched_domain *sd)
4384 +{
4385 + struct ctl_table *table = sd_alloc_ctl_entry(13);
4386 +
4387 + if (table == NULL)
4388 + return NULL;
4389 +
4390 + set_table_entry(&table[0], "min_interval", &sd->min_interval,
4391 + sizeof(long), 0644, proc_doulongvec_minmax);
4392 + set_table_entry(&table[1], "max_interval", &sd->max_interval,
4393 + sizeof(long), 0644, proc_doulongvec_minmax);
4394 + set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
4395 + sizeof(int), 0644, proc_dointvec_minmax);
4396 + set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
4397 + sizeof(int), 0644, proc_dointvec_minmax);
4398 + set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
4399 + sizeof(int), 0644, proc_dointvec_minmax);
4400 + set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
4401 + sizeof(int), 0644, proc_dointvec_minmax);
4402 + set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
4403 + sizeof(int), 0644, proc_dointvec_minmax);
4404 + set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
4405 + sizeof(int), 0644, proc_dointvec_minmax);
4406 + set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
4407 + sizeof(int), 0644, proc_dointvec_minmax);
4408 + set_table_entry(&table[9], "cache_nice_tries",
4409 + &sd->cache_nice_tries,
4410 + sizeof(int), 0644, proc_dointvec_minmax);
4411 + set_table_entry(&table[10], "flags", &sd->flags,
4412 + sizeof(int), 0644, proc_dointvec_minmax);
4413 + set_table_entry(&table[11], "name", sd->name,
4414 + CORENAME_MAX_SIZE, 0444, proc_dostring);
4415 + /* &table[12] is terminator */
4416 +
4417 + return table;
4418 +}
4419 +
4420 +static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
4421 +{
4422 + struct ctl_table *entry, *table;
4423 + struct sched_domain *sd;
4424 + int domain_num = 0, i;
4425 + char buf[32];
4426 +
4427 + for_each_domain(cpu, sd)
4428 + domain_num++;
4429 + entry = table = sd_alloc_ctl_entry(domain_num + 1);
4430 + if (table == NULL)
4431 + return NULL;
4432 +
4433 + i = 0;
4434 + for_each_domain(cpu, sd) {
4435 + snprintf(buf, 32, "domain%d", i);
4436 + entry->procname = kstrdup(buf, GFP_KERNEL);
4437 + entry->mode = 0555;
4438 + entry->child = sd_alloc_ctl_domain_table(sd);
4439 + entry++;
4440 + i++;
4441 + }
4442 + return table;
4443 +}
4444 +
4445 +static struct ctl_table_header *sd_sysctl_header;
4446 +static void register_sched_domain_sysctl(void)
4447 +{
4448 + int i, cpu_num = num_online_cpus();
4449 + struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
4450 + char buf[32];
4451 +
4452 + WARN_ON(sd_ctl_dir[0].child);
4453 + sd_ctl_dir[0].child = entry;
4454 +
4455 + if (entry == NULL)
4456 + return;
4457 +
4458 + for_each_online_cpu(i) {
4459 + snprintf(buf, 32, "cpu%d", i);
4460 + entry->procname = kstrdup(buf, GFP_KERNEL);
4461 + entry->mode = 0555;
4462 + entry->child = sd_alloc_ctl_cpu_table(i);
4463 + entry++;
4464 + }
4465 +
4466 + WARN_ON(sd_sysctl_header);
4467 + sd_sysctl_header = register_sysctl_table(sd_ctl_root);
4468 +}
4469 +
4470 +/* may be called multiple times per register */
4471 +static void unregister_sched_domain_sysctl(void)
4472 +{
4473 + if (sd_sysctl_header)
4474 + unregister_sysctl_table(sd_sysctl_header);
4475 + sd_sysctl_header = NULL;
4476 + if (sd_ctl_dir[0].child)
4477 + sd_free_ctl_entry(&sd_ctl_dir[0].child);
4478 +}
4479 +#else
4480 +static void register_sched_domain_sysctl(void)
4481 +{
4482 +}
4483 +static void unregister_sched_domain_sysctl(void)
4484 +{
4485 +}
4486 +#endif
4487 +
4488 +static void set_rq_online(struct rq *rq)
4489 +{
4490 + if (!rq->online) {
4491 + cpumask_set_cpu(rq->cpu, rq->rd->online);
4492 + rq->online = 1;
4493 + }
4494 +}
4495 +
4496 +static void set_rq_offline(struct rq *rq)
4497 +{
4498 + if (rq->online) {
4499 + cpumask_clear_cpu(rq->cpu, rq->rd->online);
4500 + rq->online = 0;
4501 + }
4502 +}
4503 +
4504 +#ifdef CONFIG_HOTPLUG_CPU
4505 +/*
4506 + * This cpu is going down, so walk over the tasklist and find tasks that can
4507 + * only run on this cpu and remove their affinity. Store their value in
4508 + * unplugged_mask so it can be restored once their correct cpu is online. No
4509 + * need to do anything special since they'll just move on next reschedule if
4510 + * they're running.
4511 + */
4512 +static void remove_cpu(unsigned long cpu)
4513 +{
4514 + struct task_struct *p, *t;
4515 +
4516 + read_lock(&tasklist_lock);
4517 +
4518 + do_each_thread(t, p) {
4519 + cpumask_t cpus_remaining;
4520 +
4521 + cpus_and(cpus_remaining, p->cpus_allowed, cpu_online_map);
4522 + cpu_clear(cpu, cpus_remaining);
4523 + if (cpus_empty(cpus_remaining)) {
4524 + p->unplugged_mask = p->cpus_allowed;
4525 + p->cpus_allowed = cpu_possible_map;
4526 + }
4527 + } while_each_thread(t, p);
4528 +
4529 + read_unlock(&tasklist_lock);
4530 +}
4531 +
4532 +/*
4533 + * This cpu is coming up so add it to the cpus_allowed.
4534 + */
4535 +static void add_cpu(unsigned long cpu)
4536 +{
4537 + struct task_struct *p, *t;
4538 +
4539 + read_lock(&tasklist_lock);
4540 +
4541 + do_each_thread(t, p) {
4542 + /* Have we taken all the cpus from the unplugged_mask back */
4543 + if (cpus_empty(p->unplugged_mask))
4544 + continue;
4545 +
4546 + /* Was this cpu in the unplugged_mask mask */
4547 + if (cpu_isset(cpu, p->unplugged_mask)) {
4548 + cpu_set(cpu, p->cpus_allowed);
4549 + if (cpus_subset(p->unplugged_mask, p->cpus_allowed)) {
4550 + /*
4551 + * Have we set more than the unplugged_mask?
4552 + * If so, that means we have remnants set from
4553 + * the unplug/plug cycle and need to remove
4554 + * them. Then clear the unplugged_mask as we've
4555 + * set all the cpus back.
4556 + */
4557 + p->cpus_allowed = p->unplugged_mask;
4558 + cpus_clear(p->unplugged_mask);
4559 + }
4560 + }
4561 + } while_each_thread(t, p);
4562 +
4563 + read_unlock(&tasklist_lock);
4564 +}
4565 +#else
4566 +static void add_cpu(unsigned long cpu)
4567 +{
4568 +}
4569 +#endif
4570 +
4571 +/*
4572 + * migration_call - callback that gets triggered when a CPU is added.
4573 + */
4574 +static int __cpuinit
4575 +migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
4576 +{
4577 + int cpu = (long)hcpu;
4578 + unsigned long flags;
4579 + struct rq *rq;
4580 +
4581 + switch (action) {
4582 +
4583 + case CPU_UP_PREPARE:
4584 + case CPU_UP_PREPARE_FROZEN:
4585 + break;
4586 +
4587 + case CPU_ONLINE:
4588 + case CPU_ONLINE_FROZEN:
4589 + /* Update our root-domain */
4590 + rq = cpu_rq(cpu);
4591 + grq_lock_irqsave(&flags);
4592 + if (rq->rd) {
4593 + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
4594 +
4595 + set_rq_online(rq);
4596 + }
4597 + add_cpu(cpu);
4598 + grq_unlock_irqrestore(&flags);
4599 + break;
4600 +
4601 +#ifdef CONFIG_HOTPLUG_CPU
4602 + case CPU_UP_CANCELED:
4603 + case CPU_UP_CANCELED_FROZEN:
4604 + break;
4605 +
4606 + case CPU_DEAD:
4607 + case CPU_DEAD_FROZEN:
4608 + cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
4609 + rq = cpu_rq(cpu);
4610 + /* Idle task back to normal (off runqueue, low prio) */
4611 + grq_lock_irq();
4612 + remove_cpu(cpu);
4613 + deactivate_task(rq->idle);
4614 + rq->idle->static_prio = MAX_PRIO;
4615 + __setscheduler(rq->idle, SCHED_NORMAL, 0);
4616 + rq->idle->prio = PRIO_LIMIT;
4617 + update_rq_clock(rq);
4618 + grq_unlock_irq();
4619 + cpuset_unlock();
4620 + break;
4621 +
4622 + case CPU_DYING:
4623 + case CPU_DYING_FROZEN:
4624 + rq = cpu_rq(cpu);
4625 + grq_lock_irqsave(&flags);
4626 + if (rq->rd) {
4627 + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
4628 + set_rq_offline(rq);
4629 + }
4630 + grq_unlock_irqrestore(&flags);
4631 + break;
4632 +#endif
4633 + }
4634 + return NOTIFY_OK;
4635 +}
4636 +
4637 +/*
4638 + * Register at high priority so that task migration (migrate_all_tasks)
4639 + * happens before everything else. This has to be lower priority than
4640 + * the notifier in the perf_counter subsystem, though.
4641 + */
4642 +static struct notifier_block __cpuinitdata migration_notifier = {
4643 + .notifier_call = migration_call,
4644 + .priority = 10
4645 +};
4646 +
4647 +int __init migration_init(void)
4648 +{
4649 + void *cpu = (void *)(long)smp_processor_id();
4650 + int err;
4651 +
4652 + /* Start one for the boot CPU: */
4653 + err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
4654 + BUG_ON(err == NOTIFY_BAD);
4655 + migration_call(&migration_notifier, CPU_ONLINE, cpu);
4656 + register_cpu_notifier(&migration_notifier);
4657 +
4658 + return 0;
4659 +}
4660 +early_initcall(migration_init);
4661 +#endif
4662 +
4663 +/*
4664 + * sched_domains_mutex serializes calls to arch_init_sched_domains,
4665 + * detach_destroy_domains and partition_sched_domains.
4666 + */
4667 +static DEFINE_MUTEX(sched_domains_mutex);
4668 +
4669 +#ifdef CONFIG_SMP
4670 +
4671 +#ifdef CONFIG_SCHED_DEBUG
4672 +
4673 +static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
4674 + struct cpumask *groupmask)
4675 +{
4676 + struct sched_group *group = sd->groups;
4677 + char str[256];
4678 +
4679 + cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
4680 + cpumask_clear(groupmask);
4681 +
4682 + printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
4683 +
4684 + if (!(sd->flags & SD_LOAD_BALANCE)) {
4685 + printk("does not load-balance\n");
4686 + if (sd->parent)
4687 + printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
4688 + " has parent");
4689 + return -1;
4690 + }
4691 +
4692 + printk(KERN_CONT "span %s level %s\n", str, sd->name);
4693 +
4694 + if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
4695 + printk(KERN_ERR "ERROR: domain->span does not contain "
4696 + "CPU%d\n", cpu);
4697 + }
4698 + if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
4699 + printk(KERN_ERR "ERROR: domain->groups does not contain"
4700 + " CPU%d\n", cpu);
4701 + }
4702 +
4703 + printk(KERN_DEBUG "%*s groups:", level + 1, "");
4704 + do {
4705 + if (!group) {
4706 + printk("\n");
4707 + printk(KERN_ERR "ERROR: group is NULL\n");
4708 + break;
4709 + }
4710 +
4711 + if (!group->__cpu_power) {
4712 + printk(KERN_CONT "\n");
4713 + printk(KERN_ERR "ERROR: domain->cpu_power not "
4714 + "set\n");
4715 + break;
4716 + }
4717 +
4718 + if (!cpumask_weight(sched_group_cpus(group))) {
4719 + printk(KERN_CONT "\n");
4720 + printk(KERN_ERR "ERROR: empty group\n");
4721 + break;
4722 + }
4723 +
4724 + if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
4725 + printk(KERN_CONT "\n");
4726 + printk(KERN_ERR "ERROR: repeated CPUs\n");
4727 + break;
4728 + }
4729 +
4730 + cpumask_or(groupmask, groupmask, sched_group_cpus(group));
4731 +
4732 + cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
4733 +
4734 + printk(KERN_CONT " %s", str);
4735 + if (group->__cpu_power != SCHED_LOAD_SCALE) {
4736 + printk(KERN_CONT " (__cpu_power = %d)",
4737 + group->__cpu_power);
4738 + }
4739 +
4740 + group = group->next;
4741 + } while (group != sd->groups);
4742 + printk(KERN_CONT "\n");
4743 +
4744 + if (!cpumask_equal(sched_domain_span(sd), groupmask))
4745 + printk(KERN_ERR "ERROR: groups don't span domain->span\n");
4746 +
4747 + if (sd->parent &&
4748 + !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
4749 + printk(KERN_ERR "ERROR: parent span is not a superset "
4750 + "of domain->span\n");
4751 + return 0;
4752 +}
4753 +
4754 +static void sched_domain_debug(struct sched_domain *sd, int cpu)
4755 +{
4756 + cpumask_var_t groupmask;
4757 + int level = 0;
4758 +
4759 + if (!sd) {
4760 + printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
4761 + return;
4762 + }
4763 +
4764 + printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
4765 +
4766 + if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
4767 + printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
4768 + return;
4769 + }
4770 +
4771 + for (;;) {
4772 + if (sched_domain_debug_one(sd, cpu, level, groupmask))
4773 + break;
4774 + level++;
4775 + sd = sd->parent;
4776 + if (!sd)
4777 + break;
4778 + }
4779 + free_cpumask_var(groupmask);
4780 +}
4781 +#else /* !CONFIG_SCHED_DEBUG */
4782 +# define sched_domain_debug(sd, cpu) do { } while (0)
4783 +#endif /* CONFIG_SCHED_DEBUG */
4784 +
4785 +static int sd_degenerate(struct sched_domain *sd)
4786 +{
4787 + if (cpumask_weight(sched_domain_span(sd)) == 1)
4788 + return 1;
4789 +
4790 + /* Following flags need at least 2 groups */
4791 + if (sd->flags & (SD_LOAD_BALANCE |
4792 + SD_BALANCE_NEWIDLE |
4793 + SD_BALANCE_FORK |
4794 + SD_BALANCE_EXEC |
4795 + SD_SHARE_CPUPOWER |
4796 + SD_SHARE_PKG_RESOURCES)) {
4797 + if (sd->groups != sd->groups->next)
4798 + return 0;
4799 + }
4800 +
4801 + /* Following flags don't use groups */
4802 + if (sd->flags & (SD_WAKE_IDLE |
4803 + SD_WAKE_AFFINE |
4804 + SD_WAKE_BALANCE))
4805 + return 0;
4806 +
4807 + return 1;
4808 +}
4809 +
4810 +static int
4811 +sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
4812 +{
4813 + unsigned long cflags = sd->flags, pflags = parent->flags;
4814 +
4815 + if (sd_degenerate(parent))
4816 + return 1;
4817 +
4818 + if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
4819 + return 0;
4820 +
4821 + /* Does parent contain flags not in child? */
4822 + /* WAKE_BALANCE is a subset of WAKE_AFFINE */
4823 + if (cflags & SD_WAKE_AFFINE)
4824 + pflags &= ~SD_WAKE_BALANCE;
4825 + /* Flags needing groups don't count if only 1 group in parent */
4826 + if (parent->groups == parent->groups->next) {
4827 + pflags &= ~(SD_LOAD_BALANCE |
4828 + SD_BALANCE_NEWIDLE |
4829 + SD_BALANCE_FORK |
4830 + SD_BALANCE_EXEC |
4831 + SD_SHARE_CPUPOWER |
4832 + SD_SHARE_PKG_RESOURCES);
4833 + if (nr_node_ids == 1)
4834 + pflags &= ~SD_SERIALIZE;
4835 + }
4836 + if (~cflags & pflags)
4837 + return 0;
4838 +
4839 + return 1;
4840 +}
4841 +
4842 +static void free_rootdomain(struct root_domain *rd)
4843 +{
4844 + free_cpumask_var(rd->rto_mask);
4845 + free_cpumask_var(rd->online);
4846 + free_cpumask_var(rd->span);
4847 + kfree(rd);
4848 +}
4849 +
4850 +static void rq_attach_root(struct rq *rq, struct root_domain *rd)
4851 +{
4852 + struct root_domain *old_rd = NULL;
4853 + unsigned long flags;
4854 +
4855 + grq_lock_irqsave(&flags);
4856 +
4857 + if (rq->rd) {
4858 + old_rd = rq->rd;
4859 +
4860 + if (cpumask_test_cpu(rq->cpu, old_rd->online))
4861 + set_rq_offline(rq);
4862 +
4863 + cpumask_clear_cpu(rq->cpu, old_rd->span);
4864 +
4865 + /*
4866 + * If we dont want to free the old_rt yet then
4867 + * set old_rd to NULL to skip the freeing later
4868 + * in this function:
4869 + */
4870 + if (!atomic_dec_and_test(&old_rd->refcount))
4871 + old_rd = NULL;
4872 + }
4873 +
4874 + atomic_inc(&rd->refcount);
4875 + rq->rd = rd;
4876 +
4877 + cpumask_set_cpu(rq->cpu, rd->span);
4878 + if (cpumask_test_cpu(rq->cpu, cpu_online_mask))
4879 + set_rq_online(rq);
4880 +
4881 + grq_unlock_irqrestore(&flags);
4882 +
4883 + if (old_rd)
4884 + free_rootdomain(old_rd);
4885 +}
4886 +
4887 +static int init_rootdomain(struct root_domain *rd, bool bootmem)
4888 +{
4889 + gfp_t gfp = GFP_KERNEL;
4890 +
4891 + memset(rd, 0, sizeof(*rd));
4892 +
4893 + if (bootmem)
4894 + gfp = GFP_NOWAIT;
4895 +
4896 + if (!alloc_cpumask_var(&rd->span, gfp))
4897 + goto out;
4898 + if (!alloc_cpumask_var(&rd->online, gfp))
4899 + goto free_span;
4900 + if (!alloc_cpumask_var(&rd->rto_mask, gfp))
4901 + goto free_online;
4902 +
4903 + return 0;
4904 +
4905 +free_online:
4906 + free_cpumask_var(rd->online);
4907 +free_span:
4908 + free_cpumask_var(rd->span);
4909 +out:
4910 + return -ENOMEM;
4911 +}
4912 +
4913 +static void init_defrootdomain(void)
4914 +{
4915 + init_rootdomain(&def_root_domain, true);
4916 +
4917 + atomic_set(&def_root_domain.refcount, 1);
4918 +}
4919 +
4920 +static struct root_domain *alloc_rootdomain(void)
4921 +{
4922 + struct root_domain *rd;
4923 +
4924 + rd = kmalloc(sizeof(*rd), GFP_KERNEL);
4925 + if (!rd)
4926 + return NULL;
4927 +
4928 + if (init_rootdomain(rd, false) != 0) {
4929 + kfree(rd);
4930 + return NULL;
4931 + }
4932 +
4933 + return rd;
4934 +}
4935 +
4936 +/*
4937 + * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
4938 + * hold the hotplug lock.
4939 + */
4940 +static void
4941 +cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
4942 +{
4943 + struct rq *rq = cpu_rq(cpu);
4944 + struct sched_domain *tmp;
4945 +
4946 + /* Remove the sched domains which do not contribute to scheduling. */
4947 + for (tmp = sd; tmp; ) {
4948 + struct sched_domain *parent = tmp->parent;
4949 + if (!parent)
4950 + break;
4951 +
4952 + if (sd_parent_degenerate(tmp, parent)) {
4953 + tmp->parent = parent->parent;
4954 + if (parent->parent)
4955 + parent->parent->child = tmp;
4956 + } else
4957 + tmp = tmp->parent;
4958 + }
4959 +
4960 + if (sd && sd_degenerate(sd)) {
4961 + sd = sd->parent;
4962 + if (sd)
4963 + sd->child = NULL;
4964 + }
4965 +
4966 + sched_domain_debug(sd, cpu);
4967 +
4968 + rq_attach_root(rq, rd);
4969 + rcu_assign_pointer(rq->sd, sd);
4970 +}
4971 +
4972 +/* cpus with isolated domains */
4973 +static cpumask_var_t cpu_isolated_map;
4974 +
4975 +/* Setup the mask of cpus configured for isolated domains */
4976 +static int __init isolated_cpu_setup(char *str)
4977 +{
4978 + cpulist_parse(str, cpu_isolated_map);
4979 + return 1;
4980 +}
4981 +
4982 +__setup("isolcpus=", isolated_cpu_setup);
4983 +
4984 +/*
4985 + * init_sched_build_groups takes the cpumask we wish to span, and a pointer
4986 + * to a function which identifies what group(along with sched group) a CPU
4987 + * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
4988 + * (due to the fact that we keep track of groups covered with a struct cpumask).
4989 + *
4990 + * init_sched_build_groups will build a circular linked list of the groups
4991 + * covered by the given span, and will set each group's ->cpumask correctly,
4992 + * and ->cpu_power to 0.
4993 + */
4994 +static void
4995 +init_sched_build_groups(const struct cpumask *span,
4996 + const struct cpumask *cpu_map,
4997 + int (*group_fn)(int cpu, const struct cpumask *cpu_map,
4998 + struct sched_group **sg,
4999 + struct cpumask *tmpmask),
5000 + struct cpumask *covered, struct cpumask *tmpmask)
5001 +{
5002 + struct sched_group *first = NULL, *last = NULL;
5003 + int i;
5004 +
5005 + cpumask_clear(covered);
5006 +
5007 + for_each_cpu(i, span) {
5008 + struct sched_group *sg;
5009 + int group = group_fn(i, cpu_map, &sg, tmpmask);
5010 + int j;
5011 +
5012 + if (cpumask_test_cpu(i, covered))
5013 + continue;
5014 +
5015 + cpumask_clear(sched_group_cpus(sg));
5016 + sg->__cpu_power = 0;
5017 +
5018 + for_each_cpu(j, span) {
5019 + if (group_fn(j, cpu_map, NULL, tmpmask) != group)
5020 + continue;
5021 +
5022 + cpumask_set_cpu(j, covered);
5023 + cpumask_set_cpu(j, sched_group_cpus(sg));
5024 + }
5025 + if (!first)
5026 + first = sg;
5027 + if (last)
5028 + last->next = sg;
5029 + last = sg;
5030 + }
5031 + last->next = first;
5032 +}
5033 +
5034 +#define SD_NODES_PER_DOMAIN 16
5035 +
5036 +#ifdef CONFIG_NUMA
5037 +
5038 +/**
5039 + * find_next_best_node - find the next node to include in a sched_domain
5040 + * @node: node whose sched_domain we're building
5041 + * @used_nodes: nodes already in the sched_domain
5042 + *
5043 + * Find the next node to include in a given scheduling domain. Simply
5044 + * finds the closest node not already in the @used_nodes map.
5045 + *
5046 + * Should use nodemask_t.
5047 + */
5048 +static int find_next_best_node(int node, nodemask_t *used_nodes)
5049 +{
5050 + int i, n, val, min_val, best_node = 0;
5051 +
5052 + min_val = INT_MAX;
5053 +
5054 + for (i = 0; i < nr_node_ids; i++) {
5055 + /* Start at @node */
5056 + n = (node + i) % nr_node_ids;
5057 +
5058 + if (!nr_cpus_node(n))
5059 + continue;
5060 +
5061 + /* Skip already used nodes */
5062 + if (node_isset(n, *used_nodes))
5063 + continue;
5064 +
5065 + /* Simple min distance search */
5066 + val = node_distance(node, n);
5067 +
5068 + if (val < min_val) {
5069 + min_val = val;
5070 + best_node = n;
5071 + }
5072 + }
5073 +
5074 + node_set(best_node, *used_nodes);
5075 + return best_node;
5076 +}
5077 +
5078 +/**
5079 + * sched_domain_node_span - get a cpumask for a node's sched_domain
5080 + * @node: node whose cpumask we're constructing
5081 + * @span: resulting cpumask
5082 + *
5083 + * Given a node, construct a good cpumask for its sched_domain to span. It
5084 + * should be one that prevents unnecessary balancing, but also spreads tasks
5085 + * out optimally.
5086 + */
5087 +static void sched_domain_node_span(int node, struct cpumask *span)
5088 +{
5089 + nodemask_t used_nodes;
5090 + int i;
5091 +
5092 + cpumask_clear(span);
5093 + nodes_clear(used_nodes);
5094 +
5095 + cpumask_or(span, span, cpumask_of_node(node));
5096 + node_set(node, used_nodes);
5097 +
5098 + for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
5099 + int next_node = find_next_best_node(node, &used_nodes);
5100 +
5101 + cpumask_or(span, span, cpumask_of_node(next_node));
5102 + }
5103 +}
5104 +#endif /* CONFIG_NUMA */
5105 +
5106 +int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
5107 +
5108 +/*
5109 + * The cpus mask in sched_group and sched_domain hangs off the end.
5110 + *
5111 + * ( See the the comments in include/linux/sched.h:struct sched_group
5112 + * and struct sched_domain. )
5113 + */
5114 +struct static_sched_group {
5115 + struct sched_group sg;
5116 + DECLARE_BITMAP(cpus, CONFIG_NR_CPUS);
5117 +};
5118 +
5119 +struct static_sched_domain {
5120 + struct sched_domain sd;
5121 + DECLARE_BITMAP(span, CONFIG_NR_CPUS);
5122 +};
5123 +
5124 +/*
5125 + * SMT sched-domains:
5126 + */
5127 +#ifdef CONFIG_SCHED_SMT
5128 +static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
5129 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
5130 +
5131 +static int
5132 +cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
5133 + struct sched_group **sg, struct cpumask *unused)
5134 +{
5135 + if (sg)
5136 + *sg = &per_cpu(sched_group_cpus, cpu).sg;
5137 + return cpu;
5138 +}
5139 +#endif /* CONFIG_SCHED_SMT */
5140 +
5141 +/*
5142 + * multi-core sched-domains:
5143 + */
5144 +#ifdef CONFIG_SCHED_MC
5145 +static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
5146 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
5147 +#endif /* CONFIG_SCHED_MC */
5148 +
5149 +#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
5150 +static int
5151 +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
5152 + struct sched_group **sg, struct cpumask *mask)
5153 +{
5154 + int group;
5155 +
5156 + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
5157 + group = cpumask_first(mask);
5158 + if (sg)
5159 + *sg = &per_cpu(sched_group_core, group).sg;
5160 + return group;
5161 +}
5162 +#elif defined(CONFIG_SCHED_MC)
5163 +static int
5164 +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
5165 + struct sched_group **sg, struct cpumask *unused)
5166 +{
5167 + if (sg)
5168 + *sg = &per_cpu(sched_group_core, cpu).sg;
5169 + return cpu;
5170 +}
5171 +#endif
5172 +
5173 +static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
5174 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
5175 +
5176 +static int
5177 +cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
5178 + struct sched_group **sg, struct cpumask *mask)
5179 +{
5180 + int group;
5181 +#ifdef CONFIG_SCHED_MC
5182 + cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
5183 + group = cpumask_first(mask);
5184 +#elif defined(CONFIG_SCHED_SMT)
5185 + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
5186 + group = cpumask_first(mask);
5187 +#else
5188 + group = cpu;
5189 +#endif
5190 + if (sg)
5191 + *sg = &per_cpu(sched_group_phys, group).sg;
5192 + return group;
5193 +}
5194 +
5195 +/**
5196 + * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
5197 + * @group: The group whose first cpu is to be returned.
5198 + */
5199 +static inline unsigned int group_first_cpu(struct sched_group *group)
5200 +{
5201 + return cpumask_first(sched_group_cpus(group));
5202 +}
5203 +
5204 +#ifdef CONFIG_NUMA
5205 +/*
5206 + * The init_sched_build_groups can't handle what we want to do with node
5207 + * groups, so roll our own. Now each node has its own list of groups which
5208 + * gets dynamically allocated.
5209 + */
5210 +static DEFINE_PER_CPU(struct static_sched_domain, node_domains);
5211 +static struct sched_group ***sched_group_nodes_bycpu;
5212 +
5213 +static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains);
5214 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes);
5215 +
5216 +static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map,
5217 + struct sched_group **sg,
5218 + struct cpumask *nodemask)
5219 +{
5220 + int group;
5221 +
5222 + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);
5223 + group = cpumask_first(nodemask);
5224 +
5225 + if (sg)
5226 + *sg = &per_cpu(sched_group_allnodes, group).sg;
5227 + return group;
5228 +}
5229 +
5230 +static void init_numa_sched_groups_power(struct sched_group *group_head)
5231 +{
5232 + struct sched_group *sg = group_head;
5233 + int j;
5234 +
5235 + if (!sg)
5236 + return;
5237 + do {
5238 + for_each_cpu(j, sched_group_cpus(sg)) {
5239 + struct sched_domain *sd;
5240 +
5241 + sd = &per_cpu(phys_domains, j).sd;
5242 + if (j != group_first_cpu(sd->groups)) {
5243 + /*
5244 + * Only add "power" once for each
5245 + * physical package.
5246 + */
5247 + continue;
5248 + }
5249 +
5250 + sg_inc_cpu_power(sg, sd->groups->__cpu_power);
5251 + }
5252 + sg = sg->next;
5253 + } while (sg != group_head);
5254 +}
5255 +#endif /* CONFIG_NUMA */
5256 +
5257 +#ifdef CONFIG_NUMA
5258 +/* Free memory allocated for various sched_group structures */
5259 +static void free_sched_groups(const struct cpumask *cpu_map,
5260 + struct cpumask *nodemask)
5261 +{
5262 + int cpu, i;
5263 +
5264 + for_each_cpu(cpu, cpu_map) {
5265 + struct sched_group **sched_group_nodes
5266 + = sched_group_nodes_bycpu[cpu];
5267 +
5268 + if (!sched_group_nodes)
5269 + continue;
5270 +
5271 + for (i = 0; i < nr_node_ids; i++) {
5272 + struct sched_group *oldsg, *sg = sched_group_nodes[i];
5273 +
5274 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5275 + if (cpumask_empty(nodemask))
5276 + continue;
5277 +
5278 + if (sg == NULL)
5279 + continue;
5280 + sg = sg->next;
5281 +next_sg:
5282 + oldsg = sg;
5283 + sg = sg->next;
5284 + kfree(oldsg);
5285 + if (oldsg != sched_group_nodes[i])
5286 + goto next_sg;
5287 + }
5288 + kfree(sched_group_nodes);
5289 + sched_group_nodes_bycpu[cpu] = NULL;
5290 + }
5291 +}
5292 +#else /* !CONFIG_NUMA */
5293 +static void free_sched_groups(const struct cpumask *cpu_map,
5294 + struct cpumask *nodemask)
5295 +{
5296 +}
5297 +#endif /* CONFIG_NUMA */
5298 +
5299 +/*
5300 + * Initialize sched groups cpu_power.
5301 + *
5302 + * cpu_power indicates the capacity of sched group, which is used while
5303 + * distributing the load between different sched groups in a sched domain.
5304 + * Typically cpu_power for all the groups in a sched domain will be same unless
5305 + * there are asymmetries in the topology. If there are asymmetries, group
5306 + * having more cpu_power will pickup more load compared to the group having
5307 + * less cpu_power.
5308 + *
5309 + * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
5310 + * the maximum number of tasks a group can handle in the presence of other idle
5311 + * or lightly loaded groups in the same sched domain.
5312 + */
5313 +static void init_sched_groups_power(int cpu, struct sched_domain *sd)
5314 +{
5315 + struct sched_domain *child;
5316 + struct sched_group *group;
5317 +
5318 + WARN_ON(!sd || !sd->groups);
5319 +
5320 + if (cpu != group_first_cpu(sd->groups))
5321 + return;
5322 +
5323 + child = sd->child;
5324 +
5325 + sd->groups->__cpu_power = 0;
5326 +
5327 + /*
5328 + * For perf policy, if the groups in child domain share resources
5329 + * (for example cores sharing some portions of the cache hierarchy
5330 + * or SMT), then set this domain groups cpu_power such that each group
5331 + * can handle only one task, when there are other idle groups in the
5332 + * same sched domain.
5333 + */
5334 + if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
5335 + (child->flags &
5336 + (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
5337 + sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
5338 + return;
5339 + }
5340 +
5341 + /*
5342 + * add cpu_power of each child group to this groups cpu_power
5343 + */
5344 + group = child->groups;
5345 + do {
5346 + sg_inc_cpu_power(sd->groups, group->__cpu_power);
5347 + group = group->next;
5348 + } while (group != child->groups);
5349 +}
5350 +
5351 +/*
5352 + * Initializers for schedule domains
5353 + * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
5354 + */
5355 +
5356 +#ifdef CONFIG_SCHED_DEBUG
5357 +# define SD_INIT_NAME(sd, type) sd->name = #type
5358 +#else
5359 +# define SD_INIT_NAME(sd, type) do { } while (0)
5360 +#endif
5361 +
5362 +#define SD_INIT(sd, type) sd_init_##type(sd)
5363 +
5364 +#define SD_INIT_FUNC(type) \
5365 +static noinline void sd_init_##type(struct sched_domain *sd) \
5366 +{ \
5367 + memset(sd, 0, sizeof(*sd)); \
5368 + *sd = SD_##type##_INIT; \
5369 + sd->level = SD_LV_##type; \
5370 + SD_INIT_NAME(sd, type); \
5371 +}
5372 +
5373 +SD_INIT_FUNC(CPU)
5374 +#ifdef CONFIG_NUMA
5375 + SD_INIT_FUNC(ALLNODES)
5376 + SD_INIT_FUNC(NODE)
5377 +#endif
5378 +#ifdef CONFIG_SCHED_SMT
5379 + SD_INIT_FUNC(SIBLING)
5380 +#endif
5381 +#ifdef CONFIG_SCHED_MC
5382 + SD_INIT_FUNC(MC)
5383 +#endif
5384 +
5385 +static int default_relax_domain_level = -1;
5386 +
5387 +static int __init setup_relax_domain_level(char *str)
5388 +{
5389 + unsigned long val;
5390 +
5391 + val = simple_strtoul(str, NULL, 0);
5392 + if (val < SD_LV_MAX)
5393 + default_relax_domain_level = val;
5394 +
5395 + return 1;
5396 +}
5397 +__setup("relax_domain_level=", setup_relax_domain_level);
5398 +
5399 +static void set_domain_attribute(struct sched_domain *sd,
5400 + struct sched_domain_attr *attr)
5401 +{
5402 + int request;
5403 +
5404 + if (!attr || attr->relax_domain_level < 0) {
5405 + if (default_relax_domain_level < 0)
5406 + return;
5407 + else
5408 + request = default_relax_domain_level;
5409 + } else
5410 + request = attr->relax_domain_level;
5411 + if (request < sd->level) {
5412 + /* turn off idle balance on this domain */
5413 + sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
5414 + } else {
5415 + /* turn on idle balance on this domain */
5416 + sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
5417 + }
5418 +}
5419 +
5420 +/*
5421 + * Build sched domains for a given set of cpus and attach the sched domains
5422 + * to the individual cpus
5423 + */
5424 +static int __build_sched_domains(const struct cpumask *cpu_map,
5425 + struct sched_domain_attr *attr)
5426 +{
5427 + int i, err = -ENOMEM;
5428 + struct root_domain *rd;
5429 + cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered,
5430 + tmpmask;
5431 +#ifdef CONFIG_NUMA
5432 + cpumask_var_t domainspan, covered, notcovered;
5433 + struct sched_group **sched_group_nodes = NULL;
5434 + int sd_allnodes = 0;
5435 +
5436 + if (!alloc_cpumask_var(&domainspan, GFP_KERNEL))
5437 + goto out;
5438 + if (!alloc_cpumask_var(&covered, GFP_KERNEL))
5439 + goto free_domainspan;
5440 + if (!alloc_cpumask_var(&notcovered, GFP_KERNEL))
5441 + goto free_covered;
5442 +#endif
5443 +
5444 + if (!alloc_cpumask_var(&nodemask, GFP_KERNEL))
5445 + goto free_notcovered;
5446 + if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL))
5447 + goto free_nodemask;
5448 + if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL))
5449 + goto free_this_sibling_map;
5450 + if (!alloc_cpumask_var(&send_covered, GFP_KERNEL))
5451 + goto free_this_core_map;
5452 + if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
5453 + goto free_send_covered;
5454 +
5455 +#ifdef CONFIG_NUMA
5456 + /*
5457 + * Allocate the per-node list of sched groups
5458 + */
5459 + sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
5460 + GFP_KERNEL);
5461 + if (!sched_group_nodes) {
5462 + printk(KERN_WARNING "Can not alloc sched group node list\n");
5463 + goto free_tmpmask;
5464 + }
5465 +#endif
5466 +
5467 + rd = alloc_rootdomain();
5468 + if (!rd) {
5469 + printk(KERN_WARNING "Cannot alloc root domain\n");
5470 + goto free_sched_groups;
5471 + }
5472 +
5473 +#ifdef CONFIG_NUMA
5474 + sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes;
5475 +#endif
5476 +
5477 + /*
5478 + * Set up domains for cpus specified by the cpu_map.
5479 + */
5480 + for_each_cpu(i, cpu_map) {
5481 + struct sched_domain *sd = NULL, *p;
5482 +
5483 + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);
5484 +
5485 +#ifdef CONFIG_NUMA
5486 + if (cpumask_weight(cpu_map) >
5487 + SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) {
5488 + sd = &per_cpu(allnodes_domains, i).sd;
5489 + SD_INIT(sd, ALLNODES);
5490 + set_domain_attribute(sd, attr);
5491 + cpumask_copy(sched_domain_span(sd), cpu_map);
5492 + cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
5493 + p = sd;
5494 + sd_allnodes = 1;
5495 + } else
5496 + p = NULL;
5497 +
5498 + sd = &per_cpu(node_domains, i).sd;
5499 + SD_INIT(sd, NODE);
5500 + set_domain_attribute(sd, attr);
5501 + sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
5502 + sd->parent = p;
5503 + if (p)
5504 + p->child = sd;
5505 + cpumask_and(sched_domain_span(sd),
5506 + sched_domain_span(sd), cpu_map);
5507 +#endif
5508 +
5509 + p = sd;
5510 + sd = &per_cpu(phys_domains, i).sd;
5511 + SD_INIT(sd, CPU);
5512 + set_domain_attribute(sd, attr);
5513 + cpumask_copy(sched_domain_span(sd), nodemask);
5514 + sd->parent = p;
5515 + if (p)
5516 + p->child = sd;
5517 + cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
5518 +
5519 +#ifdef CONFIG_SCHED_MC
5520 + p = sd;
5521 + sd = &per_cpu(core_domains, i).sd;
5522 + SD_INIT(sd, MC);
5523 + set_domain_attribute(sd, attr);
5524 + cpumask_and(sched_domain_span(sd), cpu_map,
5525 + cpu_coregroup_mask(i));
5526 + sd->parent = p;
5527 + p->child = sd;
5528 + cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
5529 +#endif
5530 +
5531 +#ifdef CONFIG_SCHED_SMT
5532 + p = sd;
5533 + sd = &per_cpu(cpu_domains, i).sd;
5534 + SD_INIT(sd, SIBLING);
5535 + set_domain_attribute(sd, attr);
5536 + cpumask_and(sched_domain_span(sd),
5537 + topology_thread_cpumask(i), cpu_map);
5538 + sd->parent = p;
5539 + p->child = sd;
5540 + cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
5541 +#endif
5542 + }
5543 +
5544 +#ifdef CONFIG_SCHED_SMT
5545 + /* Set up CPU (sibling) groups */
5546 + for_each_cpu(i, cpu_map) {
5547 + cpumask_and(this_sibling_map,
5548 + topology_thread_cpumask(i), cpu_map);
5549 + if (i != cpumask_first(this_sibling_map))
5550 + continue;
5551 +
5552 + init_sched_build_groups(this_sibling_map, cpu_map,
5553 + &cpu_to_cpu_group,
5554 + send_covered, tmpmask);
5555 + }
5556 +#endif
5557 +
5558 +#ifdef CONFIG_SCHED_MC
5559 + /* Set up multi-core groups */
5560 + for_each_cpu(i, cpu_map) {
5561 + cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);
5562 + if (i != cpumask_first(this_core_map))
5563 + continue;
5564 +
5565 + init_sched_build_groups(this_core_map, cpu_map,
5566 + &cpu_to_core_group,
5567 + send_covered, tmpmask);
5568 + }
5569 +#endif
5570 +
5571 + /* Set up physical groups */
5572 + for (i = 0; i < nr_node_ids; i++) {
5573 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5574 + if (cpumask_empty(nodemask))
5575 + continue;
5576 +
5577 + init_sched_build_groups(nodemask, cpu_map,
5578 + &cpu_to_phys_group,
5579 + send_covered, tmpmask);
5580 + }
5581 +
5582 +#ifdef CONFIG_NUMA
5583 + /* Set up node groups */
5584 + if (sd_allnodes) {
5585 + init_sched_build_groups(cpu_map, cpu_map,
5586 + &cpu_to_allnodes_group,
5587 + send_covered, tmpmask);
5588 + }
5589 +
5590 + for (i = 0; i < nr_node_ids; i++) {
5591 + /* Set up node groups */
5592 + struct sched_group *sg, *prev;
5593 + int j;
5594 +
5595 + cpumask_clear(covered);
5596 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5597 + if (cpumask_empty(nodemask)) {
5598 + sched_group_nodes[i] = NULL;
5599 + continue;
5600 + }
5601 +
5602 + sched_domain_node_span(i, domainspan);
5603 + cpumask_and(domainspan, domainspan, cpu_map);
5604 +
5605 + sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
5606 + GFP_KERNEL, i);
5607 + if (!sg) {
5608 + printk(KERN_WARNING "Can not alloc domain group for "
5609 + "node %d\n", i);
5610 + goto error;
5611 + }
5612 + sched_group_nodes[i] = sg;
5613 + for_each_cpu(j, nodemask) {
5614 + struct sched_domain *sd;
5615 +
5616 + sd = &per_cpu(node_domains, j).sd;
5617 + sd->groups = sg;
5618 + }
5619 + sg->__cpu_power = 0;
5620 + cpumask_copy(sched_group_cpus(sg), nodemask);
5621 + sg->next = sg;
5622 + cpumask_or(covered, covered, nodemask);
5623 + prev = sg;
5624 +
5625 + for (j = 0; j < nr_node_ids; j++) {
5626 + int n = (i + j) % nr_node_ids;
5627 +
5628 + cpumask_complement(notcovered, covered);
5629 + cpumask_and(tmpmask, notcovered, cpu_map);
5630 + cpumask_and(tmpmask, tmpmask, domainspan);
5631 + if (cpumask_empty(tmpmask))
5632 + break;
5633 +
5634 + cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));
5635 + if (cpumask_empty(tmpmask))
5636 + continue;
5637 +
5638 + sg = kmalloc_node(sizeof(struct sched_group) +
5639 + cpumask_size(),
5640 + GFP_KERNEL, i);
5641 + if (!sg) {
5642 + printk(KERN_WARNING
5643 + "Can not alloc domain group for node %d\n", j);
5644 + goto error;
5645 + }
5646 + sg->__cpu_power = 0;
5647 + cpumask_copy(sched_group_cpus(sg), tmpmask);
5648 + sg->next = prev->next;
5649 + cpumask_or(covered, covered, tmpmask);
5650 + prev->next = sg;
5651 + prev = sg;
5652 + }
5653 + }
5654 +#endif
5655 +
5656 + /* Calculate CPU power for physical packages and nodes */
5657 +#ifdef CONFIG_SCHED_SMT
5658 + for_each_cpu(i, cpu_map) {
5659 + struct sched_domain *sd = &per_cpu(cpu_domains, i).sd;
5660 +
5661 + init_sched_groups_power(i, sd);
5662 + }
5663 +#endif
5664 +#ifdef CONFIG_SCHED_MC
5665 + for_each_cpu(i, cpu_map) {
5666 + struct sched_domain *sd = &per_cpu(core_domains, i).sd;
5667 +
5668 + init_sched_groups_power(i, sd);
5669 + }
5670 +#endif
5671 +
5672 + for_each_cpu(i, cpu_map) {
5673 + struct sched_domain *sd = &per_cpu(phys_domains, i).sd;
5674 +
5675 + init_sched_groups_power(i, sd);
5676 + }
5677 +
5678 +#ifdef CONFIG_NUMA
5679 + for (i = 0; i < nr_node_ids; i++)
5680 + init_numa_sched_groups_power(sched_group_nodes[i]);
5681 +
5682 + if (sd_allnodes) {
5683 + struct sched_group *sg;
5684 +
5685 + cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
5686 + tmpmask);
5687 + init_numa_sched_groups_power(sg);
5688 + }
5689 +#endif
5690 +
5691 + /* Attach the domains */
5692 + for_each_cpu(i, cpu_map) {
5693 + struct sched_domain *sd;
5694 +#ifdef CONFIG_SCHED_SMT
5695 + sd = &per_cpu(cpu_domains, i).sd;
5696 +#elif defined(CONFIG_SCHED_MC)
5697 + sd = &per_cpu(core_domains, i).sd;
5698 +#else
5699 + sd = &per_cpu(phys_domains, i).sd;
5700 +#endif
5701 + cpu_attach_domain(sd, rd, i);
5702 + }
5703 +
5704 + err = 0;
5705 +
5706 +free_tmpmask:
5707 + free_cpumask_var(tmpmask);
5708 +free_send_covered:
5709 + free_cpumask_var(send_covered);
5710 +free_this_core_map:
5711 + free_cpumask_var(this_core_map);
5712 +free_this_sibling_map:
5713 + free_cpumask_var(this_sibling_map);
5714 +free_nodemask:
5715 + free_cpumask_var(nodemask);
5716 +free_notcovered:
5717 +#ifdef CONFIG_NUMA
5718 + free_cpumask_var(notcovered);
5719 +free_covered:
5720 + free_cpumask_var(covered);
5721 +free_domainspan:
5722 + free_cpumask_var(domainspan);
5723 +out:
5724 +#endif
5725 + return err;
5726 +
5727 +free_sched_groups:
5728 +#ifdef CONFIG_NUMA
5729 + kfree(sched_group_nodes);
5730 +#endif
5731 + goto free_tmpmask;
5732 +
5733 +#ifdef CONFIG_NUMA
5734 +error:
5735 + free_sched_groups(cpu_map, tmpmask);
5736 + free_rootdomain(rd);
5737 + goto free_tmpmask;
5738 +#endif
5739 +}
5740 +
5741 +static int build_sched_domains(const struct cpumask *cpu_map)
5742 +{
5743 + return __build_sched_domains(cpu_map, NULL);
5744 +}
5745 +
5746 +static struct cpumask *doms_cur; /* current sched domains */
5747 +static int ndoms_cur; /* number of sched domains in 'doms_cur' */
5748 +static struct sched_domain_attr *dattr_cur;
5749 + /* attribues of custom domains in 'doms_cur' */
5750 +
5751 +/*
5752 + * Special case: If a kmalloc of a doms_cur partition (array of
5753 + * cpumask) fails, then fallback to a single sched domain,
5754 + * as determined by the single cpumask fallback_doms.
5755 + */
5756 +static cpumask_var_t fallback_doms;
5757 +
5758 +/*
5759 + * arch_update_cpu_topology lets virtualized architectures update the
5760 + * cpu core maps. It is supposed to return 1 if the topology changed
5761 + * or 0 if it stayed the same.
5762 + */
5763 +int __attribute__((weak)) arch_update_cpu_topology(void)
5764 +{
5765 + return 0;
5766 +}
5767 +
5768 +/*
5769 + * Set up scheduler domains and groups. Callers must hold the hotplug lock.
5770 + * For now this just excludes isolated cpus, but could be used to
5771 + * exclude other special cases in the future.
5772 + */
5773 +static int arch_init_sched_domains(const struct cpumask *cpu_map)
5774 +{
5775 + int err;
5776 +
5777 + arch_update_cpu_topology();
5778 + ndoms_cur = 1;
5779 + doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
5780 + if (!doms_cur)
5781 + doms_cur = fallback_doms;
5782 + cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
5783 + dattr_cur = NULL;
5784 + err = build_sched_domains(doms_cur);
5785 + register_sched_domain_sysctl();
5786 +
5787 + return err;
5788 +}
5789 +
5790 +static void arch_destroy_sched_domains(const struct cpumask *cpu_map,
5791 + struct cpumask *tmpmask)
5792 +{
5793 + free_sched_groups(cpu_map, tmpmask);
5794 +}
5795 +
5796 +/*
5797 + * Detach sched domains from a group of cpus specified in cpu_map
5798 + * These cpus will now be attached to the NULL domain
5799 + */
5800 +static void detach_destroy_domains(const struct cpumask *cpu_map)
5801 +{
5802 + /* Save because hotplug lock held. */
5803 + static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
5804 + int i;
5805 +
5806 + for_each_cpu(i, cpu_map)
5807 + cpu_attach_domain(NULL, &def_root_domain, i);
5808 + synchronize_sched();
5809 + arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask));
5810 +}
5811 +
5812 +/* handle null as "default" */
5813 +static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
5814 + struct sched_domain_attr *new, int idx_new)
5815 +{
5816 + struct sched_domain_attr tmp;
5817 +
5818 + /* fast path */
5819 + if (!new && !cur)
5820 + return 1;
5821 +
5822 + tmp = SD_ATTR_INIT;
5823 + return !memcmp(cur ? (cur + idx_cur) : &tmp,
5824 + new ? (new + idx_new) : &tmp,
5825 + sizeof(struct sched_domain_attr));
5826 +}
5827 +
5828 +/*
5829 + * Partition sched domains as specified by the 'ndoms_new'
5830 + * cpumasks in the array doms_new[] of cpumasks. This compares
5831 + * doms_new[] to the current sched domain partitioning, doms_cur[].
5832 + * It destroys each deleted domain and builds each new domain.
5833 + *
5834 + * 'doms_new' is an array of cpumask's of length 'ndoms_new'.
5835 + * The masks don't intersect (don't overlap.) We should setup one
5836 + * sched domain for each mask. CPUs not in any of the cpumasks will
5837 + * not be load balanced. If the same cpumask appears both in the
5838 + * current 'doms_cur' domains and in the new 'doms_new', we can leave
5839 + * it as it is.
5840 + *
5841 + * The passed in 'doms_new' should be kmalloc'd. This routine takes
5842 + * ownership of it and will kfree it when done with it. If the caller
5843 + * failed the kmalloc call, then it can pass in doms_new == NULL &&
5844 + * ndoms_new == 1, and partition_sched_domains() will fallback to
5845 + * the single partition 'fallback_doms', it also forces the domains
5846 + * to be rebuilt.
5847 + *
5848 + * If doms_new == NULL it will be replaced with cpu_online_mask.
5849 + * ndoms_new == 0 is a special case for destroying existing domains,
5850 + * and it will not create the default domain.
5851 + *
5852 + * Call with hotplug lock held
5853 + */
5854 +/* FIXME: Change to struct cpumask *doms_new[] */
5855 +void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
5856 + struct sched_domain_attr *dattr_new)
5857 +{
5858 + int i, j, n;
5859 + int new_topology;
5860 +
5861 + mutex_lock(&sched_domains_mutex);
5862 +
5863 + /* always unregister in case we don't destroy any domains */
5864 + unregister_sched_domain_sysctl();
5865 +
5866 + /* Let architecture update cpu core mappings. */
5867 + new_topology = arch_update_cpu_topology();
5868 +
5869 + n = doms_new ? ndoms_new : 0;
5870 +
5871 + /* Destroy deleted domains */
5872 + for (i = 0; i < ndoms_cur; i++) {
5873 + for (j = 0; j < n && !new_topology; j++) {
5874 + if (cpumask_equal(&doms_cur[i], &doms_new[j])
5875 + && dattrs_equal(dattr_cur, i, dattr_new, j))
5876 + goto match1;
5877 + }
5878 + /* no match - a current sched domain not in new doms_new[] */
5879 + detach_destroy_domains(doms_cur + i);
5880 +match1:
5881 + ;
5882 + }
5883 +
5884 + if (doms_new == NULL) {
5885 + ndoms_cur = 0;
5886 + doms_new = fallback_doms;
5887 + cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
5888 + WARN_ON_ONCE(dattr_new);
5889 + }
5890 +
5891 + /* Build new domains */
5892 + for (i = 0; i < ndoms_new; i++) {
5893 + for (j = 0; j < ndoms_cur && !new_topology; j++) {
5894 + if (cpumask_equal(&doms_new[i], &doms_cur[j])
5895 + && dattrs_equal(dattr_new, i, dattr_cur, j))
5896 + goto match2;
5897 + }
5898 + /* no match - add a new doms_new */
5899 + __build_sched_domains(doms_new + i,
5900 + dattr_new ? dattr_new + i : NULL);
5901 +match2:
5902 + ;
5903 + }
5904 +
5905 + /* Remember the new sched domains */
5906 + if (doms_cur != fallback_doms)
5907 + kfree(doms_cur);
5908 + kfree(dattr_cur); /* kfree(NULL) is safe */
5909 + doms_cur = doms_new;
5910 + dattr_cur = dattr_new;
5911 + ndoms_cur = ndoms_new;
5912 +
5913 + register_sched_domain_sysctl();
5914 +
5915 + mutex_unlock(&sched_domains_mutex);
5916 +}
5917 +
5918 +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
5919 +static void arch_reinit_sched_domains(void)
5920 +{
5921 + get_online_cpus();
5922 +
5923 + /* Destroy domains first to force the rebuild */
5924 + partition_sched_domains(0, NULL, NULL);
5925 +
5926 + rebuild_sched_domains();
5927 + put_online_cpus();
5928 +}
5929 +
5930 +static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
5931 +{
5932 + unsigned int level = 0;
5933 +
5934 + if (sscanf(buf, "%u", &level) != 1)
5935 + return -EINVAL;
5936 +
5937 + /*
5938 + * level is always be positive so don't check for
5939 + * level < POWERSAVINGS_BALANCE_NONE which is 0
5940 + * What happens on 0 or 1 byte write,
5941 + * need to check for count as well?
5942 + */
5943 +
5944 + if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
5945 + return -EINVAL;
5946 +
5947 + if (smt)
5948 + sched_smt_power_savings = level;
5949 + else
5950 + sched_mc_power_savings = level;
5951 +
5952 + arch_reinit_sched_domains();
5953 +
5954 + return count;
5955 +}
5956 +
5957 +#ifdef CONFIG_SCHED_MC
5958 +static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
5959 + char *page)
5960 +{
5961 + return sprintf(page, "%u\n", sched_mc_power_savings);
5962 +}
5963 +static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
5964 + const char *buf, size_t count)
5965 +{
5966 + return sched_power_savings_store(buf, count, 0);
5967 +}
5968 +static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
5969 + sched_mc_power_savings_show,
5970 + sched_mc_power_savings_store);
5971 +#endif
5972 +
5973 +#ifdef CONFIG_SCHED_SMT
5974 +static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
5975 + char *page)
5976 +{
5977 + return sprintf(page, "%u\n", sched_smt_power_savings);
5978 +}
5979 +static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
5980 + const char *buf, size_t count)
5981 +{
5982 + return sched_power_savings_store(buf, count, 1);
5983 +}
5984 +static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
5985 + sched_smt_power_savings_show,
5986 + sched_smt_power_savings_store);
5987 +#endif
5988 +
5989 +int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
5990 +{
5991 + int err = 0;
5992 +
5993 +#ifdef CONFIG_SCHED_SMT
5994 + if (smt_capable())
5995 + err = sysfs_create_file(&cls->kset.kobj,
5996 + &attr_sched_smt_power_savings.attr);
5997 +#endif
5998 +#ifdef CONFIG_SCHED_MC
5999 + if (!err && mc_capable())
6000 + err = sysfs_create_file(&cls->kset.kobj,
6001 + &attr_sched_mc_power_savings.attr);
6002 +#endif
6003 + return err;
6004 +}
6005 +#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
6006 +
6007 +#ifndef CONFIG_CPUSETS
6008 +/*
6009 + * Add online and remove offline CPUs from the scheduler domains.
6010 + * When cpusets are enabled they take over this function.
6011 + */
6012 +static int update_sched_domains(struct notifier_block *nfb,
6013 + unsigned long action, void *hcpu)
6014 +{
6015 + switch (action) {
6016 + case CPU_ONLINE:
6017 + case CPU_ONLINE_FROZEN:
6018 + case CPU_DEAD:
6019 + case CPU_DEAD_FROZEN:
6020 + partition_sched_domains(1, NULL, NULL);
6021 + return NOTIFY_OK;
6022 +
6023 + default:
6024 + return NOTIFY_DONE;
6025 + }
6026 +}
6027 +#endif
6028 +
6029 +static int update_runtime(struct notifier_block *nfb,
6030 + unsigned long action, void *hcpu)
6031 +{
6032 + switch (action) {
6033 + case CPU_DOWN_PREPARE:
6034 + case CPU_DOWN_PREPARE_FROZEN:
6035 + return NOTIFY_OK;
6036 +
6037 + case CPU_DOWN_FAILED:
6038 + case CPU_DOWN_FAILED_FROZEN:
6039 + case CPU_ONLINE:
6040 + case CPU_ONLINE_FROZEN:
6041 + return NOTIFY_OK;
6042 +
6043 + default:
6044 + return NOTIFY_DONE;
6045 + }
6046 +}
6047 +
6048 +void __init sched_init_smp(void)
6049 +{
6050 + cpumask_var_t non_isolated_cpus;
6051 +
6052 + alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
6053 +
6054 +#if defined(CONFIG_NUMA)
6055 + sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
6056 + GFP_KERNEL);
6057 + BUG_ON(sched_group_nodes_bycpu == NULL);
6058 +#endif
6059 + get_online_cpus();
6060 + mutex_lock(&sched_domains_mutex);
6061 + arch_init_sched_domains(cpu_online_mask);
6062 + cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
6063 + if (cpumask_empty(non_isolated_cpus))
6064 + cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
6065 + mutex_unlock(&sched_domains_mutex);
6066 + put_online_cpus();
6067 +
6068 +#ifndef CONFIG_CPUSETS
6069 + /* XXX: Theoretical race here - CPU may be hotplugged now */
6070 + hotcpu_notifier(update_sched_domains, 0);
6071 +#endif
6072 +
6073 + /* RT runtime code needs to handle some hotplug events */
6074 + hotcpu_notifier(update_runtime, 0);
6075 +
6076 + /* Move init over to a non-isolated CPU */
6077 + if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
6078 + BUG();
6079 + free_cpumask_var(non_isolated_cpus);
6080 +
6081 + alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
6082 +
6083 + /*
6084 + * Assume that every added cpu gives us slightly less overall latency
6085 + * allowing us to increase the base rr_interval, but in a non linear
6086 + * fashion.
6087 + */
6088 + rr_interval *= 1 + ilog2(num_online_cpus());
6089 +}
6090 +#else
6091 +void __init sched_init_smp(void)
6092 +{
6093 +}
6094 +#endif /* CONFIG_SMP */
6095 +
6096 +unsigned int sysctl_timer_migration = 1;
6097 +
6098 +int in_sched_functions(unsigned long addr)
6099 +{
6100 + return in_lock_functions(addr) ||
6101 + (addr >= (unsigned long)__sched_text_start
6102 + && addr < (unsigned long)__sched_text_end);
6103 +}
6104 +
6105 +void __init sched_init(void)
6106 +{
6107 + int i;
6108 + int highest_cpu = 0;
6109 +
6110 + prio_ratios[0] = 100;
6111 + for (i = 1 ; i < PRIO_RANGE ; i++)
6112 + prio_ratios[i] = prio_ratios[i - 1] * 11 / 10;
6113 +
6114 +#ifdef CONFIG_SMP
6115 + init_defrootdomain();
6116 + cpus_clear(grq.cpu_idle_map);
6117 +#endif
6118 + spin_lock_init(&grq.lock);
6119 + for_each_possible_cpu(i) {
6120 + struct rq *rq;
6121 +
6122 + rq = cpu_rq(i);
6123 + INIT_LIST_HEAD(&rq->queue);
6124 + rq->rq_deadline = 0;
6125 + rq->rq_prio = 0;
6126 + rq->cpu = i;
6127 + rq->user_pc = rq->nice_pc = rq->softirq_pc = rq->system_pc =
6128 + rq->iowait_pc = rq->idle_pc = 0;
6129 +#ifdef CONFIG_SMP
6130 + rq->sd = NULL;
6131 + rq->rd = NULL;
6132 + rq->online = 0;
6133 + INIT_LIST_HEAD(&rq->migration_queue);
6134 + rq_attach_root(rq, &def_root_domain);
6135 +#endif
6136 + atomic_set(&rq->nr_iowait, 0);
6137 + highest_cpu = i;
6138 + }
6139 + grq.iso_ticks = grq.nr_running = grq.nr_uninterruptible = 0;
6140 + for (i = 0; i < PRIO_LIMIT; i++)
6141 + INIT_LIST_HEAD(grq.queue + i);
6142 + bitmap_zero(grq.prio_bitmap, PRIO_LIMIT);
6143 + /* delimiter for bitsearch */
6144 + __set_bit(PRIO_LIMIT, grq.prio_bitmap);
6145 +
6146 +#ifdef CONFIG_SMP
6147 + nr_cpu_ids = highest_cpu + 1;
6148 +#endif
6149 +
6150 +#ifdef CONFIG_PREEMPT_NOTIFIERS
6151 + INIT_HLIST_HEAD(&init_task.preempt_notifiers);
6152 +#endif
6153 +
6154 +#ifdef CONFIG_RT_MUTEXES
6155 + plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
6156 +#endif
6157 +
6158 + /*
6159 + * The boot idle thread does lazy MMU switching as well:
6160 + */
6161 + atomic_inc(&init_mm.mm_count);
6162 + enter_lazy_tlb(&init_mm, current);
6163 +
6164 + /*
6165 + * Make us the idle thread. Technically, schedule() should not be
6166 + * called from this thread, however somewhere below it might be,
6167 + * but because we are the idle thread, we just pick up running again
6168 + * when this runqueue becomes "idle".
6169 + */
6170 + init_idle(current, smp_processor_id());
6171 +
6172 + /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
6173 + alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
6174 +#ifdef CONFIG_SMP
6175 +#ifdef CONFIG_NO_HZ
6176 + alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
6177 + alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
6178 +#endif
6179 + alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
6180 +#endif /* SMP */
6181 + perf_counter_init();
6182 +}
6183 +
6184 +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
6185 +void __might_sleep(char *file, int line)
6186 +{
6187 +#ifdef in_atomic
6188 + static unsigned long prev_jiffy; /* ratelimiting */
6189 +
6190 + if ((in_atomic() || irqs_disabled()) &&
6191 + system_state == SYSTEM_RUNNING && !oops_in_progress) {
6192 + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
6193 + return;
6194 + prev_jiffy = jiffies;
6195 + printk(KERN_ERR "BUG: sleeping function called from invalid"
6196 + " context at %s:%d\n", file, line);
6197 + printk("in_atomic():%d, irqs_disabled():%d\n",
6198 + in_atomic(), irqs_disabled());
6199 + debug_show_held_locks(current);
6200 + if (irqs_disabled())
6201 + print_irqtrace_events(current);
6202 + dump_stack();
6203 + }
6204 +#endif
6205 +}
6206 +EXPORT_SYMBOL(__might_sleep);
6207 +#endif
6208 +
6209 +#ifdef CONFIG_MAGIC_SYSRQ
6210 +void normalize_rt_tasks(void)
6211 +{
6212 + struct task_struct *g, *p;
6213 + unsigned long flags;
6214 + struct rq *rq;
6215 + int queued;
6216 +
6217 + read_lock_irq(&tasklist_lock);
6218 +
6219 + do_each_thread(g, p) {
6220 + if (!rt_task(p) && !iso_task(p))
6221 + continue;
6222 +
6223 + spin_lock_irqsave(&p->pi_lock, flags);
6224 + rq = __task_grq_lock(p);
6225 + update_rq_clock(rq);
6226 +
6227 + queued = task_queued_only(p);
6228 + if (queued)
6229 + dequeue_task(p);
6230 + __setscheduler(p, SCHED_NORMAL, 0);
6231 + if (task_running(p))
6232 + resched_task(p);
6233 + if (queued) {
6234 + enqueue_task(p);
6235 + try_preempt(p);
6236 + }
6237 +
6238 + __task_grq_unlock();
6239 + spin_unlock_irqrestore(&p->pi_lock, flags);
6240 + } while_each_thread(g, p);
6241 +
6242 + read_unlock_irq(&tasklist_lock);
6243 +}
6244 +#endif /* CONFIG_MAGIC_SYSRQ */
6245 +
6246 +#ifdef CONFIG_IA64
6247 +/*
6248 + * These functions are only useful for the IA64 MCA handling.
6249 + *
6250 + * They can only be called when the whole system has been
6251 + * stopped - every CPU needs to be quiescent, and no scheduling
6252 + * activity can take place. Using them for anything else would
6253 + * be a serious bug, and as a result, they aren't even visible
6254 + * under any other configuration.
6255 + */
6256 +
6257 +/**
6258 + * curr_task - return the current task for a given cpu.
6259 + * @cpu: the processor in question.
6260 + *
6261 + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
6262 + */
6263 +struct task_struct *curr_task(int cpu)
6264 +{
6265 + return cpu_curr(cpu);
6266 +}
6267 +
6268 +/**
6269 + * set_curr_task - set the current task for a given cpu.
6270 + * @cpu: the processor in question.
6271 + * @p: the task pointer to set.
6272 + *
6273 + * Description: This function must only be used when non-maskable interrupts
6274 + * are serviced on a separate stack. It allows the architecture to switch the
6275 + * notion of the current task on a cpu in a non-blocking manner. This function
6276 + * must be called with all CPU's synchronized, and interrupts disabled, the
6277 + * and caller must save the original value of the current task (see
6278 + * curr_task() above) and restore that value before reenabling interrupts and
6279 + * re-starting the system.
6280 + *
6281 + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
6282 + */
6283 +void set_curr_task(int cpu, struct task_struct *p)
6284 +{
6285 + cpu_curr(cpu) = p;
6286 +}
6287 +
6288 +#endif
6289 +
6290 +/*
6291 + * Use precise platform statistics if available:
6292 + */
6293 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING
6294 +cputime_t task_utime(struct task_struct *p)
6295 +{
6296 + return p->utime;
6297 +}
6298 +
6299 +cputime_t task_stime(struct task_struct *p)
6300 +{
6301 + return p->stime;
6302 +}
6303 +#else
6304 +cputime_t task_utime(struct task_struct *p)
6305 +{
6306 + clock_t utime = cputime_to_clock_t(p->utime),
6307 + total = utime + cputime_to_clock_t(p->stime);
6308 + u64 temp;
6309 +
6310 + temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
6311 +
6312 + if (total) {
6313 + temp *= utime;
6314 + do_div(temp, total);
6315 + }
6316 + utime = (clock_t)temp;
6317 +
6318 + p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
6319 + return p->prev_utime;
6320 +}
6321 +
6322 +cputime_t task_stime(struct task_struct *p)
6323 +{
6324 + clock_t stime;
6325 +
6326 + stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
6327 + cputime_to_clock_t(task_utime(p));
6328 +
6329 + if (stime >= 0)
6330 + p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
6331 +
6332 + return p->prev_stime;
6333 +}
6334 +#endif
6335 +
6336 +inline cputime_t task_gtime(struct task_struct *p)
6337 +{
6338 + return p->gtime;
6339 +}
6340 +
6341 +void __cpuinit init_idle_bootup_task(struct task_struct *idle)
6342 +{}
6343 +
6344 +#ifdef CONFIG_SCHED_DEBUG
6345 +void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
6346 +{}
6347 +
6348 +void proc_sched_set_task(struct task_struct *p)
6349 +{}
6350 +#endif
6351 --- a/kernel/sysctl.c
6352 +++ b/kernel/sysctl.c
6353 @@ -86,6 +86,8 @@ extern int percpu_pagelist_fraction;
6354 extern int compat_log;
6355 extern int latencytop_enabled;
6356 extern int sysctl_nr_open_min, sysctl_nr_open_max;
6357 +extern int rr_interval;
6358 +extern int sched_iso_cpu;
6359 #ifndef CONFIG_MMU
6360 extern int sysctl_nr_trim_pages;
6361 #endif
6362 @@ -103,7 +105,8 @@ static int zero;
6363 static int __maybe_unused one = 1;
6364 static int __maybe_unused two = 2;
6365 static unsigned long one_ul = 1;
6366 -static int one_hundred = 100;
6367 +static int __read_mostly one_hundred = 100;
6368 +static int __maybe_unused __read_mostly five_thousand = 5000;
6369
6370 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
6371 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
6372 @@ -238,7 +241,7 @@ static struct ctl_table root_table[] = {
6373 { .ctl_name = 0 }
6374 };
6375
6376 -#ifdef CONFIG_SCHED_DEBUG
6377 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
6378 static int min_sched_granularity_ns = 100000; /* 100 usecs */
6379 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
6380 static int min_wakeup_granularity_ns; /* 0 usecs */
6381 @@ -246,7 +249,7 @@ static int max_wakeup_granularity_ns = N
6382 #endif
6383
6384 static struct ctl_table kern_table[] = {
6385 -#ifdef CONFIG_SCHED_DEBUG
6386 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
6387 {
6388 .ctl_name = CTL_UNNUMBERED,
6389 .procname = "sched_min_granularity_ns",
6390 @@ -342,6 +345,7 @@ static struct ctl_table kern_table[] = {
6391 .extra2 = &one,
6392 },
6393 #endif
6394 +#ifdef CONFIG_SCHED_CFS
6395 {
6396 .ctl_name = CTL_UNNUMBERED,
6397 .procname = "sched_rt_period_us",
6398 @@ -366,6 +370,7 @@ static struct ctl_table kern_table[] = {
6399 .mode = 0644,
6400 .proc_handler = &proc_dointvec,
6401 },
6402 +#endif
6403 #ifdef CONFIG_PROVE_LOCKING
6404 {
6405 .ctl_name = CTL_UNNUMBERED,
6406 @@ -798,6 +803,30 @@ static struct ctl_table kern_table[] = {
6407 .proc_handler = &proc_dointvec,
6408 },
6409 #endif
6410 +#ifdef CONFIG_SCHED_BFS
6411 + {
6412 + .ctl_name = CTL_UNNUMBERED,
6413 + .procname = "rr_interval",
6414 + .data = &rr_interval,
6415 + .maxlen = sizeof (int),
6416 + .mode = 0644,
6417 + .proc_handler = &proc_dointvec_minmax,
6418 + .strategy = &sysctl_intvec,
6419 + .extra1 = &one,
6420 + .extra2 = &five_thousand,
6421 + },
6422 + {
6423 + .ctl_name = CTL_UNNUMBERED,
6424 + .procname = "iso_cpu",
6425 + .data = &sched_iso_cpu,
6426 + .maxlen = sizeof (int),
6427 + .mode = 0644,
6428 + .proc_handler = &proc_dointvec_minmax,
6429 + .strategy = &sysctl_intvec,
6430 + .extra1 = &zero,
6431 + .extra2 = &one_hundred,
6432 + },
6433 +#endif
6434 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
6435 {
6436 .ctl_name = KERN_SPIN_RETRY,
6437 --- a/kernel/workqueue.c
6438 +++ b/kernel/workqueue.c
6439 @@ -317,7 +317,9 @@ static int worker_thread(void *__cwq)
6440 if (cwq->wq->freezeable)
6441 set_freezable();
6442
6443 +#ifdef CONFIG_SCHED_CFS
6444 set_user_nice(current, -5);
6445 +#endif
6446
6447 for (;;) {
6448 prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
This page took 0.348346 seconds and 5 git commands to generate.