generic: fix LED control on the RTL8366 switches
[openwrt.git] / target / linux / generic / patches-2.6.30 / 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 @@ -48,6 +49,7 @@ 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 @@ -170,6 +172,16 @@ 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 @@ -322,6 +334,19 @@ 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 @@ -119,9 +119,10 @@ 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 @@ -1042,10 +1045,13 @@ 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 @@ -1096,6 +1102,7 @@ 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 @@ -1123,17 +1130,19 @@ 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 @@ -1156,6 +1165,9 @@ 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 @@ -1446,11 +1458,19 @@ 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 @@ -1734,7 +1754,7 @@ 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 @@ -435,9 +435,22 @@ 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 @@ -488,6 +501,7 @@ 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 $(CONFIG_SCHED_CFS),sched.o,sched_bfs.o) fork.o exec_domain.o panic.o printk.o \
218 cpu.o exit.o itimer.o time.o softirq.o resource.o \
219 sysctl.o capability.o ptrace.o timer.o user.o \
220 signal.o sys.o kmod.o workqueue.o pid.o \
221 @@ -103,6 +103,7 @@ ifneq ($(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 @@ -15,7 +15,11 @@
232 #include <linux/mutex.h>
233 #include <trace/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 +1,6059 @@
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_enter_lazy_cpu_mode();
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 +DEFINE_PER_CPU(struct kernel_stat, kstat);
1753 +
1754 +EXPORT_PER_CPU_SYMBOL(kstat);
1755 +
1756 +/*
1757 + * On each tick, see what percentage of that tick was attributed to each
1758 + * component and add the percentage to the _pc values. Once a _pc value has
1759 + * accumulated one tick's worth, account for that. This means the total
1760 + * percentage of load components will always be 100 per tick.
1761 + */
1762 +static void pc_idle_time(struct rq *rq, unsigned long pc)
1763 +{
1764 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1765 + cputime64_t tmp = cputime_to_cputime64(jiffies_to_cputime(1));
1766 +
1767 + if (atomic_read(&rq->nr_iowait) > 0) {
1768 + rq->iowait_pc += pc;
1769 + if (rq->iowait_pc >= 100) {
1770 + rq->iowait_pc %= 100;
1771 + cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
1772 + }
1773 + } else {
1774 + rq->idle_pc += pc;
1775 + if (rq->idle_pc >= 100) {
1776 + rq->idle_pc %= 100;
1777 + cpustat->idle = cputime64_add(cpustat->idle, tmp);
1778 + }
1779 + }
1780 +}
1781 +
1782 +static void
1783 +pc_system_time(struct rq *rq, struct task_struct *p, int hardirq_offset,
1784 + unsigned long pc, unsigned long ns)
1785 +{
1786 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1787 + cputime_t one_jiffy = jiffies_to_cputime(1);
1788 + cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
1789 + cputime64_t tmp = cputime_to_cputime64(one_jiffy);
1790 +
1791 + p->stime_pc += pc;
1792 + if (p->stime_pc >= 100) {
1793 + p->stime_pc -= 100;
1794 + p->stime = cputime_add(p->stime, one_jiffy);
1795 + p->stimescaled = cputime_add(p->stimescaled, one_jiffy_scaled);
1796 + account_group_system_time(p, one_jiffy);
1797 + acct_update_integrals(p);
1798 + }
1799 + p->se.sum_exec_runtime += ns;
1800 +
1801 + if (hardirq_count() - hardirq_offset)
1802 + rq->irq_pc += pc;
1803 + else if (softirq_count()) {
1804 + rq->softirq_pc += pc;
1805 + if (rq->softirq_pc >= 100) {
1806 + rq->softirq_pc %= 100;
1807 + cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
1808 + }
1809 + } else {
1810 + rq->system_pc += pc;
1811 + if (rq->system_pc >= 100) {
1812 + rq->system_pc %= 100;
1813 + cpustat->system = cputime64_add(cpustat->system, tmp);
1814 + }
1815 + }
1816 +}
1817 +
1818 +static void pc_user_time(struct rq *rq, struct task_struct *p,
1819 + unsigned long pc, unsigned long ns)
1820 +{
1821 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
1822 + cputime_t one_jiffy = jiffies_to_cputime(1);
1823 + cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
1824 + cputime64_t tmp = cputime_to_cputime64(one_jiffy);
1825 +
1826 + p->utime_pc += pc;
1827 + if (p->utime_pc >= 100) {
1828 + p->utime_pc -= 100;
1829 + p->utime = cputime_add(p->utime, one_jiffy);
1830 + p->utimescaled = cputime_add(p->utimescaled, one_jiffy_scaled);
1831 + account_group_user_time(p, one_jiffy);
1832 + acct_update_integrals(p);
1833 + }
1834 + p->se.sum_exec_runtime += ns;
1835 +
1836 + if (TASK_NICE(p) > 0 || idleprio_task(p)) {
1837 + rq->nice_pc += pc;
1838 + if (rq->nice_pc >= 100) {
1839 + rq->nice_pc %= 100;
1840 + cpustat->nice = cputime64_add(cpustat->nice, tmp);
1841 + }
1842 + } else {
1843 + rq->user_pc += pc;
1844 + if (rq->user_pc >= 100) {
1845 + rq->user_pc %= 100;
1846 + cpustat->user = cputime64_add(cpustat->user, tmp);
1847 + }
1848 + }
1849 +}
1850 +
1851 +/* Convert nanoseconds to percentage of one tick. */
1852 +#define NS_TO_PC(NS) (NS * 100 / JIFFIES_TO_NS(1))
1853 +
1854 +/*
1855 + * This is called on clock ticks and on context switches.
1856 + * Bank in p->se.sum_exec_runtime the ns elapsed since the last tick or switch.
1857 + * CPU scheduler quota accounting is also performed here in microseconds.
1858 + * The value returned from sched_clock() occasionally gives bogus values so
1859 + * some sanity checking is required. Time is supposed to be banked all the
1860 + * time so default to half a tick to make up for when sched_clock reverts
1861 + * to just returning jiffies, and for hardware that can't do tsc.
1862 + */
1863 +static void
1864 +update_cpu_clock(struct rq *rq, struct task_struct *p, int tick)
1865 +{
1866 + long time_diff = rq->clock - p->last_ran;
1867 + long account_ns = rq->clock - rq->timekeep_clock;
1868 + struct task_struct *idle = rq->idle;
1869 + unsigned long account_pc;
1870 +
1871 + /*
1872 + * There should be less than or equal to one jiffy worth, and not
1873 + * negative/overflow. time_diff is only used for internal scheduler
1874 + * time_slice accounting.
1875 + */
1876 + if (time_diff <= 0)
1877 + time_diff = JIFFIES_TO_NS(1) / 2;
1878 + else if (time_diff > JIFFIES_TO_NS(1))
1879 + time_diff = JIFFIES_TO_NS(1);
1880 +
1881 + if (unlikely(account_ns < 0))
1882 + account_ns = 0;
1883 +
1884 + account_pc = NS_TO_PC(account_ns);
1885 +
1886 + if (tick) {
1887 + int user_tick = user_mode(get_irq_regs());
1888 +
1889 + /* Accurate tick timekeeping */
1890 + if (user_tick)
1891 + pc_user_time(rq, p, account_pc, account_ns);
1892 + else if (p != idle || (irq_count() != HARDIRQ_OFFSET))
1893 + pc_system_time(rq, p, HARDIRQ_OFFSET,
1894 + account_pc, account_ns);
1895 + else
1896 + pc_idle_time(rq, account_pc);
1897 + } else {
1898 + /* Accurate subtick timekeeping */
1899 + if (p == idle)
1900 + pc_idle_time(rq, account_pc);
1901 + else
1902 + pc_user_time(rq, p, account_pc, account_ns);
1903 + }
1904 +
1905 + /* time_slice accounting is done in usecs to avoid overflow on 32bit */
1906 + if (rq->rq_policy != SCHED_FIFO && p != idle)
1907 + rq->rq_time_slice -= time_diff / 1000;
1908 + p->last_ran = rq->timekeep_clock = rq->clock;
1909 +}
1910 +
1911 +/*
1912 + * Return any ns on the sched_clock that have not yet been accounted in
1913 + * @p in case that task is currently running.
1914 + *
1915 + * Called with task_grq_lock() held on @rq.
1916 + */
1917 +static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
1918 +{
1919 + u64 ns = 0;
1920 +
1921 + if (p == rq->curr) {
1922 + update_rq_clock(rq);
1923 + ns = rq->clock - p->last_ran;
1924 + if ((s64)ns < 0)
1925 + ns = 0;
1926 + }
1927 +
1928 + return ns;
1929 +}
1930 +
1931 +unsigned long long task_delta_exec(struct task_struct *p)
1932 +{
1933 + unsigned long flags;
1934 + struct rq *rq;
1935 + u64 ns = 0;
1936 +
1937 + rq = task_grq_lock(p, &flags);
1938 + ns = do_task_delta_exec(p, rq);
1939 + task_grq_unlock(&flags);
1940 +
1941 + return ns;
1942 +}
1943 +
1944 +/*
1945 + * Return accounted runtime for the task.
1946 + * In case the task is currently running, return the runtime plus current's
1947 + * pending runtime that have not been accounted yet.
1948 + */
1949 +unsigned long long task_sched_runtime(struct task_struct *p)
1950 +{
1951 + unsigned long flags;
1952 + struct rq *rq;
1953 + u64 ns = 0;
1954 +
1955 + rq = task_grq_lock(p, &flags);
1956 + ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
1957 + task_grq_unlock(&flags);
1958 +
1959 + return ns;
1960 +}
1961 +
1962 +/*
1963 + * Return sum_exec_runtime for the thread group.
1964 + * In case the task is currently running, return the sum plus current's
1965 + * pending runtime that have not been accounted yet.
1966 + *
1967 + * Note that the thread group might have other running tasks as well,
1968 + * so the return value not includes other pending runtime that other
1969 + * running tasks might have.
1970 + */
1971 +unsigned long long thread_group_sched_runtime(struct task_struct *p)
1972 +{
1973 + struct task_cputime totals;
1974 + unsigned long flags;
1975 + struct rq *rq;
1976 + u64 ns;
1977 +
1978 + rq = task_grq_lock(p, &flags);
1979 + thread_group_cputime(p, &totals);
1980 + ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
1981 + task_grq_unlock(&flags);
1982 +
1983 + return ns;
1984 +}
1985 +
1986 +/* Compatibility crap for removal */
1987 +void account_user_time(struct task_struct *p, cputime_t cputime,
1988 + cputime_t cputime_scaled)
1989 +{
1990 +}
1991 +
1992 +void account_idle_time(cputime_t cputime)
1993 +{
1994 +}
1995 +
1996 +/*
1997 + * Account guest cpu time to a process.
1998 + * @p: the process that the cpu time gets accounted to
1999 + * @cputime: the cpu time spent in virtual machine since the last update
2000 + * @cputime_scaled: cputime scaled by cpu frequency
2001 + */
2002 +static void account_guest_time(struct task_struct *p, cputime_t cputime,
2003 + cputime_t cputime_scaled)
2004 +{
2005 + cputime64_t tmp;
2006 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2007 +
2008 + tmp = cputime_to_cputime64(cputime);
2009 +
2010 + /* Add guest time to process. */
2011 + p->utime = cputime_add(p->utime, cputime);
2012 + p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
2013 + account_group_user_time(p, cputime);
2014 + p->gtime = cputime_add(p->gtime, cputime);
2015 +
2016 + /* Add guest time to cpustat. */
2017 + cpustat->user = cputime64_add(cpustat->user, tmp);
2018 + cpustat->guest = cputime64_add(cpustat->guest, tmp);
2019 +}
2020 +
2021 +/*
2022 + * Account system cpu time to a process.
2023 + * @p: the process that the cpu time gets accounted to
2024 + * @hardirq_offset: the offset to subtract from hardirq_count()
2025 + * @cputime: the cpu time spent in kernel space since the last update
2026 + * @cputime_scaled: cputime scaled by cpu frequency
2027 + * This is for guest only now.
2028 + */
2029 +void account_system_time(struct task_struct *p, int hardirq_offset,
2030 + cputime_t cputime, cputime_t cputime_scaled)
2031 +{
2032 +
2033 + if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
2034 + account_guest_time(p, cputime, cputime_scaled);
2035 +}
2036 +
2037 +/*
2038 + * Account for involuntary wait time.
2039 + * @steal: the cpu time spent in involuntary wait
2040 + */
2041 +void account_steal_time(cputime_t cputime)
2042 +{
2043 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2044 + cputime64_t cputime64 = cputime_to_cputime64(cputime);
2045 +
2046 + cpustat->steal = cputime64_add(cpustat->steal, cputime64);
2047 +}
2048 +
2049 +/*
2050 + * Account for idle time.
2051 + * @cputime: the cpu time spent in idle wait
2052 + */
2053 +static void account_idle_times(cputime_t cputime)
2054 +{
2055 + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
2056 + cputime64_t cputime64 = cputime_to_cputime64(cputime);
2057 + struct rq *rq = this_rq();
2058 +
2059 + if (atomic_read(&rq->nr_iowait) > 0)
2060 + cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
2061 + else
2062 + cpustat->idle = cputime64_add(cpustat->idle, cputime64);
2063 +}
2064 +
2065 +#ifndef CONFIG_VIRT_CPU_ACCOUNTING
2066 +
2067 +void account_process_tick(struct task_struct *p, int user_tick)
2068 +{
2069 +}
2070 +
2071 +/*
2072 + * Account multiple ticks of steal time.
2073 + * @p: the process from which the cpu time has been stolen
2074 + * @ticks: number of stolen ticks
2075 + */
2076 +void account_steal_ticks(unsigned long ticks)
2077 +{
2078 + account_steal_time(jiffies_to_cputime(ticks));
2079 +}
2080 +
2081 +/*
2082 + * Account multiple ticks of idle time.
2083 + * @ticks: number of stolen ticks
2084 + */
2085 +void account_idle_ticks(unsigned long ticks)
2086 +{
2087 + account_idle_times(jiffies_to_cputime(ticks));
2088 +}
2089 +#endif
2090 +
2091 +/*
2092 + * Functions to test for when SCHED_ISO tasks have used their allocated
2093 + * quota as real time scheduling and convert them back to SCHED_NORMAL.
2094 + * Where possible, the data is tested lockless, to avoid grabbing grq_lock
2095 + * because the occasional inaccurate result won't matter. However the
2096 + * data is only ever modified under lock.
2097 + */
2098 +static void set_iso_refractory(void)
2099 +{
2100 + grq_lock();
2101 + grq.iso_refractory = 1;
2102 + grq_unlock();
2103 +}
2104 +
2105 +static void clear_iso_refractory(void)
2106 +{
2107 + grq_lock();
2108 + grq.iso_refractory = 0;
2109 + grq_unlock();
2110 +}
2111 +
2112 +/*
2113 + * Test if SCHED_ISO tasks have run longer than their alloted period as RT
2114 + * tasks and set the refractory flag if necessary. There is 10% hysteresis
2115 + * for unsetting the flag.
2116 + */
2117 +static unsigned int test_ret_isorefractory(struct rq *rq)
2118 +{
2119 + if (likely(!grq.iso_refractory)) {
2120 + if (grq.iso_ticks / ISO_PERIOD > sched_iso_cpu)
2121 + set_iso_refractory();
2122 + } else {
2123 + if (grq.iso_ticks / ISO_PERIOD < (sched_iso_cpu * 90 / 100))
2124 + clear_iso_refractory();
2125 + }
2126 + return grq.iso_refractory;
2127 +}
2128 +
2129 +static void iso_tick(void)
2130 +{
2131 + grq_lock();
2132 + grq.iso_ticks += 100;
2133 + grq_unlock();
2134 +}
2135 +
2136 +/* No SCHED_ISO task was running so decrease rq->iso_ticks */
2137 +static inline void no_iso_tick(void)
2138 +{
2139 + if (grq.iso_ticks) {
2140 + grq_lock();
2141 + grq.iso_ticks = grq.iso_ticks * (ISO_PERIOD - 1) / ISO_PERIOD;
2142 + grq_unlock();
2143 + }
2144 +}
2145 +
2146 +static int rq_running_iso(struct rq *rq)
2147 +{
2148 + return rq->rq_prio == ISO_PRIO;
2149 +}
2150 +
2151 +/* This manages tasks that have run out of timeslice during a scheduler_tick */
2152 +static void task_running_tick(struct rq *rq)
2153 +{
2154 + struct task_struct *p;
2155 +
2156 + /*
2157 + * If a SCHED_ISO task is running we increment the iso_ticks. In
2158 + * order to prevent SCHED_ISO tasks from causing starvation in the
2159 + * presence of true RT tasks we account those as iso_ticks as well.
2160 + */
2161 + if ((rt_queue(rq) || (iso_queue(rq) && !grq.iso_refractory))) {
2162 + if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100)
2163 + iso_tick();
2164 + } else
2165 + no_iso_tick();
2166 +
2167 + if (iso_queue(rq)) {
2168 + if (unlikely(test_ret_isorefractory(rq))) {
2169 + if (rq_running_iso(rq)) {
2170 + /*
2171 + * SCHED_ISO task is running as RT and limit
2172 + * has been hit. Force it to reschedule as
2173 + * SCHED_NORMAL by zeroing its time_slice
2174 + */
2175 + rq->rq_time_slice = 0;
2176 + }
2177 + }
2178 + }
2179 +
2180 + /* SCHED_FIFO tasks never run out of timeslice. */
2181 + if (rq_idle(rq) || rq->rq_time_slice > 0 || rq->rq_policy == SCHED_FIFO)
2182 + return;
2183 +
2184 + /* p->rt.time_slice <= 0. We only modify task_struct under grq lock */
2185 + grq_lock();
2186 + p = rq->curr;
2187 + if (likely(task_running(p))) {
2188 + requeue_task(p);
2189 + set_tsk_need_resched(p);
2190 + }
2191 + grq_unlock();
2192 +}
2193 +
2194 +void wake_up_idle_cpu(int cpu);
2195 +
2196 +/*
2197 + * This function gets called by the timer code, with HZ frequency.
2198 + * We call it with interrupts disabled. The data modified is all
2199 + * local to struct rq so we don't need to grab grq lock.
2200 + */
2201 +void scheduler_tick(void)
2202 +{
2203 + int cpu = smp_processor_id();
2204 + struct rq *rq = cpu_rq(cpu);
2205 +
2206 + sched_clock_tick();
2207 + update_rq_clock(rq);
2208 + update_cpu_clock(rq, rq->curr, 1);
2209 + if (!rq_idle(rq))
2210 + task_running_tick(rq);
2211 + else {
2212 + no_iso_tick();
2213 + if (unlikely(queued_notrunning()))
2214 + set_tsk_need_resched(rq->idle);
2215 + }
2216 +}
2217 +
2218 +notrace unsigned long get_parent_ip(unsigned long addr)
2219 +{
2220 + if (in_lock_functions(addr)) {
2221 + addr = CALLER_ADDR2;
2222 + if (in_lock_functions(addr))
2223 + addr = CALLER_ADDR3;
2224 + }
2225 + return addr;
2226 +}
2227 +
2228 +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
2229 + defined(CONFIG_PREEMPT_TRACER))
2230 +void __kprobes add_preempt_count(int val)
2231 +{
2232 +#ifdef CONFIG_DEBUG_PREEMPT
2233 + /*
2234 + * Underflow?
2235 + */
2236 + if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
2237 + return;
2238 +#endif
2239 + preempt_count() += val;
2240 +#ifdef CONFIG_DEBUG_PREEMPT
2241 + /*
2242 + * Spinlock count overflowing soon?
2243 + */
2244 + DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
2245 + PREEMPT_MASK - 10);
2246 +#endif
2247 + if (preempt_count() == val)
2248 + trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2249 +}
2250 +EXPORT_SYMBOL(add_preempt_count);
2251 +
2252 +void __kprobes sub_preempt_count(int val)
2253 +{
2254 +#ifdef CONFIG_DEBUG_PREEMPT
2255 + /*
2256 + * Underflow?
2257 + */
2258 + if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
2259 + return;
2260 + /*
2261 + * Is the spinlock portion underflowing?
2262 + */
2263 + if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
2264 + !(preempt_count() & PREEMPT_MASK)))
2265 + return;
2266 +#endif
2267 +
2268 + if (preempt_count() == val)
2269 + trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2270 + preempt_count() -= val;
2271 +}
2272 +EXPORT_SYMBOL(sub_preempt_count);
2273 +#endif
2274 +
2275 +/*
2276 + * Deadline is "now" in jiffies + (offset by priority). Setting the deadline
2277 + * is the key to everything. It distributes cpu fairly amongst tasks of the
2278 + * same nice value, it proportions cpu according to nice level, it means the
2279 + * task that last woke up the longest ago has the earliest deadline, thus
2280 + * ensuring that interactive tasks get low latency on wake up.
2281 + */
2282 +static inline int prio_deadline_diff(struct task_struct *p)
2283 +{
2284 + return (pratio(p) * rr_interval * HZ / 1000 / 100) ? : 1;
2285 +}
2286 +
2287 +static inline int longest_deadline(void)
2288 +{
2289 + return (prio_ratios[39] * rr_interval * HZ / 1000 / 100);
2290 +}
2291 +
2292 +/*
2293 + * SCHED_IDLE tasks still have a deadline set, but offset by to nice +19.
2294 + * This allows nice levels to work between IDLEPRIO tasks and gives a
2295 + * deadline longer than nice +19 for when they're scheduled as SCHED_NORMAL
2296 + * tasks.
2297 + */
2298 +static inline void time_slice_expired(struct task_struct *p)
2299 +{
2300 + reset_first_time_slice(p);
2301 + p->rt.time_slice = timeslice();
2302 + p->deadline = jiffies + prio_deadline_diff(p);
2303 + if (idleprio_task(p))
2304 + p->deadline += longest_deadline();
2305 +}
2306 +
2307 +static inline void check_deadline(struct task_struct *p)
2308 +{
2309 + if (p->rt.time_slice <= 0)
2310 + time_slice_expired(p);
2311 +}
2312 +
2313 +/*
2314 + * O(n) lookup of all tasks in the global runqueue. The real brainfuck
2315 + * of lock contention and O(n). It's not really O(n) as only the queued,
2316 + * but not running tasks are scanned, and is O(n) queued in the worst case
2317 + * scenario only because the right task can be found before scanning all of
2318 + * them.
2319 + * Tasks are selected in this order:
2320 + * Real time tasks are selected purely by their static priority and in the
2321 + * order they were queued, so the lowest value idx, and the first queued task
2322 + * of that priority value is chosen.
2323 + * If no real time tasks are found, the SCHED_ISO priority is checked, and
2324 + * all SCHED_ISO tasks have the same priority value, so they're selected by
2325 + * the earliest deadline value.
2326 + * If no SCHED_ISO tasks are found, SCHED_NORMAL tasks are selected by the
2327 + * earliest deadline.
2328 + * Finally if no SCHED_NORMAL tasks are found, SCHED_IDLEPRIO tasks are
2329 + * selected by the earliest deadline.
2330 + */
2331 +static inline struct
2332 +task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle)
2333 +{
2334 + unsigned long dl, earliest_deadline = 0; /* Initialise to silence compiler */
2335 + struct task_struct *p, *edt;
2336 + unsigned int cpu = rq->cpu;
2337 + struct list_head *queue;
2338 + int idx = 0;
2339 +
2340 + edt = idle;
2341 +retry:
2342 + idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx);
2343 + if (idx >= PRIO_LIMIT)
2344 + goto out;
2345 + queue = &grq.queue[idx];
2346 + list_for_each_entry(p, queue, rt.run_list) {
2347 + /* Make sure cpu affinity is ok */
2348 + if (!cpu_isset(cpu, p->cpus_allowed))
2349 + continue;
2350 + if (idx < MAX_RT_PRIO) {
2351 + /* We found an rt task */
2352 + edt = p;
2353 + goto out_take;
2354 + }
2355 +
2356 + /*
2357 + * No rt task, select the earliest deadline task now.
2358 + * On the 1st run the 2nd condition is never used, so
2359 + * there is no need to initialise earliest_deadline
2360 + * before. Normalise all old deadlines to now.
2361 + */
2362 + if (time_before(p->deadline, jiffies))
2363 + dl = jiffies;
2364 + else
2365 + dl = p->deadline;
2366 +
2367 + if (edt == idle ||
2368 + time_before(dl, earliest_deadline)) {
2369 + earliest_deadline = dl;
2370 + edt = p;
2371 + }
2372 + }
2373 + if (edt == idle) {
2374 + if (++idx < PRIO_LIMIT)
2375 + goto retry;
2376 + goto out;
2377 + }
2378 +out_take:
2379 + take_task(rq, edt);
2380 +out:
2381 + return edt;
2382 +}
2383 +
2384 +#ifdef CONFIG_SMP
2385 +static inline void set_cpuidle_map(unsigned long cpu)
2386 +{
2387 + cpu_set(cpu, grq.cpu_idle_map);
2388 +}
2389 +
2390 +static inline void clear_cpuidle_map(unsigned long cpu)
2391 +{
2392 + cpu_clear(cpu, grq.cpu_idle_map);
2393 +}
2394 +
2395 +#else /* CONFIG_SMP */
2396 +static inline void set_cpuidle_map(unsigned long cpu)
2397 +{
2398 +}
2399 +
2400 +static inline void clear_cpuidle_map(unsigned long cpu)
2401 +{
2402 +}
2403 +#endif /* !CONFIG_SMP */
2404 +
2405 +/*
2406 + * Print scheduling while atomic bug:
2407 + */
2408 +static noinline void __schedule_bug(struct task_struct *prev)
2409 +{
2410 + struct pt_regs *regs = get_irq_regs();
2411 +
2412 + printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
2413 + prev->comm, prev->pid, preempt_count());
2414 +
2415 + debug_show_held_locks(prev);
2416 + print_modules();
2417 + if (irqs_disabled())
2418 + print_irqtrace_events(prev);
2419 +
2420 + if (regs)
2421 + show_regs(regs);
2422 + else
2423 + dump_stack();
2424 +}
2425 +
2426 +/*
2427 + * Various schedule()-time debugging checks and statistics:
2428 + */
2429 +static inline void schedule_debug(struct task_struct *prev)
2430 +{
2431 + /*
2432 + * Test if we are atomic. Since do_exit() needs to call into
2433 + * schedule() atomically, we ignore that path for now.
2434 + * Otherwise, whine if we are scheduling when we should not be.
2435 + */
2436 + if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
2437 + __schedule_bug(prev);
2438 +
2439 + profile_hit(SCHED_PROFILING, __builtin_return_address(0));
2440 +
2441 + schedstat_inc(this_rq(), sched_count);
2442 +#ifdef CONFIG_SCHEDSTATS
2443 + if (unlikely(prev->lock_depth >= 0)) {
2444 + schedstat_inc(this_rq(), bkl_count);
2445 + schedstat_inc(prev, sched_info.bkl_count);
2446 + }
2447 +#endif
2448 +}
2449 +
2450 +/*
2451 + * schedule() is the main scheduler function.
2452 + */
2453 +asmlinkage void __sched __schedule(void)
2454 +{
2455 + struct task_struct *prev, *next, *idle;
2456 + int deactivate = 0, cpu;
2457 + long *switch_count;
2458 + struct rq *rq;
2459 + u64 now;
2460 +
2461 + cpu = smp_processor_id();
2462 + rq = this_rq();
2463 + rcu_qsctr_inc(cpu);
2464 + prev = rq->curr;
2465 + switch_count = &prev->nivcsw;
2466 +
2467 + release_kernel_lock(prev);
2468 +need_resched_nonpreemptible:
2469 +
2470 + schedule_debug(prev);
2471 + idle = rq->idle;
2472 + /*
2473 + * The idle thread is not allowed to schedule!
2474 + * Remove this check after it has been exercised a bit.
2475 + */
2476 + if (unlikely(prev == idle) && prev->state != TASK_RUNNING) {
2477 + printk(KERN_ERR "bad: scheduling from the idle thread!\n");
2478 + dump_stack();
2479 + }
2480 +
2481 + grq_lock_irq();
2482 + update_rq_clock(rq);
2483 + now = rq->clock;
2484 + update_cpu_clock(rq, prev, 0);
2485 +
2486 + clear_tsk_need_resched(prev);
2487 +
2488 + if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
2489 + if (unlikely(signal_pending_state(prev->state, prev)))
2490 + prev->state = TASK_RUNNING;
2491 + else
2492 + deactivate = 1;
2493 + switch_count = &prev->nvcsw;
2494 + }
2495 +
2496 + if (prev != idle) {
2497 + /* Update all the information stored on struct rq */
2498 + prev->rt.time_slice = rq->rq_time_slice;
2499 + prev->deadline = rq->rq_deadline;
2500 + check_deadline(prev);
2501 + return_task(prev, deactivate);
2502 + }
2503 +
2504 + if (likely(queued_notrunning())) {
2505 + next = earliest_deadline_task(rq, idle);
2506 + } else {
2507 + next = idle;
2508 + schedstat_inc(rq, sched_goidle);
2509 + }
2510 +
2511 + if (next == rq->idle)
2512 + set_cpuidle_map(cpu);
2513 + else
2514 + clear_cpuidle_map(cpu);
2515 +
2516 + prefetch(next);
2517 + prefetch_stack(next);
2518 +
2519 + prev->timestamp = prev->last_ran = now;
2520 +
2521 + if (likely(prev != next)) {
2522 + rq->rq_time_slice = next->rt.time_slice;
2523 + rq->rq_deadline = next->deadline;
2524 + rq->rq_prio = next->prio;
2525 +
2526 + sched_info_switch(prev, next);
2527 + grq.nr_switches++;
2528 + next->oncpu = 1;
2529 + prev->oncpu = 0;
2530 + rq->curr = next;
2531 + ++*switch_count;
2532 +
2533 + context_switch(rq, prev, next); /* unlocks the rq */
2534 + /*
2535 + * the context switch might have flipped the stack from under
2536 + * us, hence refresh the local variables.
2537 + */
2538 + cpu = smp_processor_id();
2539 + rq = cpu_rq(cpu);
2540 + } else
2541 + grq_unlock_irq();
2542 +
2543 + if (unlikely(reacquire_kernel_lock(current) < 0))
2544 + goto need_resched_nonpreemptible;
2545 +}
2546 +
2547 +asmlinkage void __sched schedule(void)
2548 +{
2549 +need_resched:
2550 + preempt_disable();
2551 + __schedule();
2552 + preempt_enable_no_resched();
2553 + if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
2554 + goto need_resched;
2555 +}
2556 +EXPORT_SYMBOL(schedule);
2557 +
2558 +#ifdef CONFIG_SMP
2559 +int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
2560 +{
2561 + return 0;
2562 +}
2563 +#endif
2564 +
2565 +#ifdef CONFIG_PREEMPT
2566 +/*
2567 + * this is the entry point to schedule() from in-kernel preemption
2568 + * off of preempt_enable. Kernel preemptions off return from interrupt
2569 + * occur there and call schedule directly.
2570 + */
2571 +asmlinkage void __sched preempt_schedule(void)
2572 +{
2573 + struct thread_info *ti = current_thread_info();
2574 +
2575 + /*
2576 + * If there is a non-zero preempt_count or interrupts are disabled,
2577 + * we do not want to preempt the current task. Just return..
2578 + */
2579 + if (likely(ti->preempt_count || irqs_disabled()))
2580 + return;
2581 +
2582 + do {
2583 + add_preempt_count(PREEMPT_ACTIVE);
2584 + schedule();
2585 + sub_preempt_count(PREEMPT_ACTIVE);
2586 +
2587 + /*
2588 + * Check again in case we missed a preemption opportunity
2589 + * between schedule and now.
2590 + */
2591 + barrier();
2592 + } while (need_resched());
2593 +}
2594 +EXPORT_SYMBOL(preempt_schedule);
2595 +
2596 +/*
2597 + * this is the entry point to schedule() from kernel preemption
2598 + * off of irq context.
2599 + * Note, that this is called and return with irqs disabled. This will
2600 + * protect us against recursive calling from irq.
2601 + */
2602 +asmlinkage void __sched preempt_schedule_irq(void)
2603 +{
2604 + struct thread_info *ti = current_thread_info();
2605 +
2606 + /* Catch callers which need to be fixed */
2607 + BUG_ON(ti->preempt_count || !irqs_disabled());
2608 +
2609 + do {
2610 + add_preempt_count(PREEMPT_ACTIVE);
2611 + local_irq_enable();
2612 + schedule();
2613 + local_irq_disable();
2614 + sub_preempt_count(PREEMPT_ACTIVE);
2615 +
2616 + /*
2617 + * Check again in case we missed a preemption opportunity
2618 + * between schedule and now.
2619 + */
2620 + barrier();
2621 + } while (need_resched());
2622 +}
2623 +
2624 +#endif /* CONFIG_PREEMPT */
2625 +
2626 +int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
2627 + void *key)
2628 +{
2629 + return try_to_wake_up(curr->private, mode, sync);
2630 +}
2631 +EXPORT_SYMBOL(default_wake_function);
2632 +
2633 +/*
2634 + * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
2635 + * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
2636 + * number) then we wake all the non-exclusive tasks and one exclusive task.
2637 + *
2638 + * There are circumstances in which we can try to wake a task which has already
2639 + * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
2640 + * zero in this (rare) case, and we handle it by continuing to scan the queue.
2641 + */
2642 +void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
2643 + int nr_exclusive, int sync, void *key)
2644 +{
2645 + struct list_head *tmp, *next;
2646 +
2647 + list_for_each_safe(tmp, next, &q->task_list) {
2648 + wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
2649 + unsigned flags = curr->flags;
2650 +
2651 + if (curr->func(curr, mode, sync, key) &&
2652 + (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
2653 + break;
2654 + }
2655 +}
2656 +
2657 +/**
2658 + * __wake_up - wake up threads blocked on a waitqueue.
2659 + * @q: the waitqueue
2660 + * @mode: which threads
2661 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2662 + * @key: is directly passed to the wakeup function
2663 + *
2664 + * It may be assumed that this function implies a write memory barrier before
2665 + * changing the task state if and only if any tasks are woken up.
2666 + */
2667 +void __wake_up(wait_queue_head_t *q, unsigned int mode,
2668 + int nr_exclusive, void *key)
2669 +{
2670 + unsigned long flags;
2671 +
2672 + spin_lock_irqsave(&q->lock, flags);
2673 + __wake_up_common(q, mode, nr_exclusive, 0, key);
2674 + spin_unlock_irqrestore(&q->lock, flags);
2675 +}
2676 +EXPORT_SYMBOL(__wake_up);
2677 +
2678 +/*
2679 + * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
2680 + */
2681 +void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
2682 +{
2683 + __wake_up_common(q, mode, 1, 0, NULL);
2684 +}
2685 +
2686 +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
2687 +{
2688 + __wake_up_common(q, mode, 1, 0, key);
2689 +}
2690 +
2691 +/**
2692 + * __wake_up_sync_key - wake up threads blocked on a waitqueue.
2693 + * @q: the waitqueue
2694 + * @mode: which threads
2695 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2696 + * @key: opaque value to be passed to wakeup targets
2697 + *
2698 + * The sync wakeup differs that the waker knows that it will schedule
2699 + * away soon, so while the target thread will be woken up, it will not
2700 + * be migrated to another CPU - ie. the two threads are 'synchronized'
2701 + * with each other. This can prevent needless bouncing between CPUs.
2702 + *
2703 + * On UP it can prevent extra preemption.
2704 + *
2705 + * It may be assumed that this function implies a write memory barrier before
2706 + * changing the task state if and only if any tasks are woken up.
2707 + */
2708 +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
2709 + int nr_exclusive, void *key)
2710 +{
2711 + unsigned long flags;
2712 + int sync = 1;
2713 +
2714 + if (unlikely(!q))
2715 + return;
2716 +
2717 + if (unlikely(!nr_exclusive))
2718 + sync = 0;
2719 +
2720 + spin_lock_irqsave(&q->lock, flags);
2721 + __wake_up_common(q, mode, nr_exclusive, sync, key);
2722 + spin_unlock_irqrestore(&q->lock, flags);
2723 +}
2724 +EXPORT_SYMBOL_GPL(__wake_up_sync_key);
2725 +
2726 +/**
2727 + * __wake_up_sync - wake up threads blocked on a waitqueue.
2728 + * @q: the waitqueue
2729 + * @mode: which threads
2730 + * @nr_exclusive: how many wake-one or wake-many threads to wake up
2731 + *
2732 + * The sync wakeup differs that the waker knows that it will schedule
2733 + * away soon, so while the target thread will be woken up, it will not
2734 + * be migrated to another CPU - ie. the two threads are 'synchronized'
2735 + * with each other. This can prevent needless bouncing between CPUs.
2736 + *
2737 + * On UP it can prevent extra preemption.
2738 + */
2739 +void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
2740 +{
2741 + unsigned long flags;
2742 + int sync = 1;
2743 +
2744 + if (unlikely(!q))
2745 + return;
2746 +
2747 + if (unlikely(!nr_exclusive))
2748 + sync = 0;
2749 +
2750 + spin_lock_irqsave(&q->lock, flags);
2751 + __wake_up_common(q, mode, nr_exclusive, sync, NULL);
2752 + spin_unlock_irqrestore(&q->lock, flags);
2753 +}
2754 +EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
2755 +
2756 +/**
2757 + * complete: - signals a single thread waiting on this completion
2758 + * @x: holds the state of this particular completion
2759 + *
2760 + * This will wake up a single thread waiting on this completion. Threads will be
2761 + * awakened in the same order in which they were queued.
2762 + *
2763 + * See also complete_all(), wait_for_completion() and related routines.
2764 + *
2765 + * It may be assumed that this function implies a write memory barrier before
2766 + * changing the task state if and only if any tasks are woken up.
2767 + */
2768 +void complete(struct completion *x)
2769 +{
2770 + unsigned long flags;
2771 +
2772 + spin_lock_irqsave(&x->wait.lock, flags);
2773 + x->done++;
2774 + __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
2775 + spin_unlock_irqrestore(&x->wait.lock, flags);
2776 +}
2777 +EXPORT_SYMBOL(complete);
2778 +
2779 +/**
2780 + * complete_all: - signals all threads waiting on this completion
2781 + * @x: holds the state of this particular completion
2782 + *
2783 + * This will wake up all threads waiting on this particular completion event.
2784 + *
2785 + * It may be assumed that this function implies a write memory barrier before
2786 + * changing the task state if and only if any tasks are woken up.
2787 + */
2788 +void complete_all(struct completion *x)
2789 +{
2790 + unsigned long flags;
2791 +
2792 + spin_lock_irqsave(&x->wait.lock, flags);
2793 + x->done += UINT_MAX/2;
2794 + __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
2795 + spin_unlock_irqrestore(&x->wait.lock, flags);
2796 +}
2797 +EXPORT_SYMBOL(complete_all);
2798 +
2799 +static inline long __sched
2800 +do_wait_for_common(struct completion *x, long timeout, int state)
2801 +{
2802 + if (!x->done) {
2803 + DECLARE_WAITQUEUE(wait, current);
2804 +
2805 + wait.flags |= WQ_FLAG_EXCLUSIVE;
2806 + __add_wait_queue_tail(&x->wait, &wait);
2807 + do {
2808 + if (signal_pending_state(state, current)) {
2809 + timeout = -ERESTARTSYS;
2810 + break;
2811 + }
2812 + __set_current_state(state);
2813 + spin_unlock_irq(&x->wait.lock);
2814 + timeout = schedule_timeout(timeout);
2815 + spin_lock_irq(&x->wait.lock);
2816 + } while (!x->done && timeout);
2817 + __remove_wait_queue(&x->wait, &wait);
2818 + if (!x->done)
2819 + return timeout;
2820 + }
2821 + x->done--;
2822 + return timeout ?: 1;
2823 +}
2824 +
2825 +static long __sched
2826 +wait_for_common(struct completion *x, long timeout, int state)
2827 +{
2828 + might_sleep();
2829 +
2830 + spin_lock_irq(&x->wait.lock);
2831 + timeout = do_wait_for_common(x, timeout, state);
2832 + spin_unlock_irq(&x->wait.lock);
2833 + return timeout;
2834 +}
2835 +
2836 +/**
2837 + * wait_for_completion: - waits for completion of a task
2838 + * @x: holds the state of this particular completion
2839 + *
2840 + * This waits to be signaled for completion of a specific task. It is NOT
2841 + * interruptible and there is no timeout.
2842 + *
2843 + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
2844 + * and interrupt capability. Also see complete().
2845 + */
2846 +void __sched wait_for_completion(struct completion *x)
2847 +{
2848 + wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
2849 +}
2850 +EXPORT_SYMBOL(wait_for_completion);
2851 +
2852 +/**
2853 + * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
2854 + * @x: holds the state of this particular completion
2855 + * @timeout: timeout value in jiffies
2856 + *
2857 + * This waits for either a completion of a specific task to be signaled or for a
2858 + * specified timeout to expire. The timeout is in jiffies. It is not
2859 + * interruptible.
2860 + */
2861 +unsigned long __sched
2862 +wait_for_completion_timeout(struct completion *x, unsigned long timeout)
2863 +{
2864 + return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
2865 +}
2866 +EXPORT_SYMBOL(wait_for_completion_timeout);
2867 +
2868 +/**
2869 + * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
2870 + * @x: holds the state of this particular completion
2871 + *
2872 + * This waits for completion of a specific task to be signaled. It is
2873 + * interruptible.
2874 + */
2875 +int __sched wait_for_completion_interruptible(struct completion *x)
2876 +{
2877 + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
2878 + if (t == -ERESTARTSYS)
2879 + return t;
2880 + return 0;
2881 +}
2882 +EXPORT_SYMBOL(wait_for_completion_interruptible);
2883 +
2884 +/**
2885 + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
2886 + * @x: holds the state of this particular completion
2887 + * @timeout: timeout value in jiffies
2888 + *
2889 + * This waits for either a completion of a specific task to be signaled or for a
2890 + * specified timeout to expire. It is interruptible. The timeout is in jiffies.
2891 + */
2892 +unsigned long __sched
2893 +wait_for_completion_interruptible_timeout(struct completion *x,
2894 + unsigned long timeout)
2895 +{
2896 + return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
2897 +}
2898 +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
2899 +
2900 +/**
2901 + * wait_for_completion_killable: - waits for completion of a task (killable)
2902 + * @x: holds the state of this particular completion
2903 + *
2904 + * This waits to be signaled for completion of a specific task. It can be
2905 + * interrupted by a kill signal.
2906 + */
2907 +int __sched wait_for_completion_killable(struct completion *x)
2908 +{
2909 + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
2910 + if (t == -ERESTARTSYS)
2911 + return t;
2912 + return 0;
2913 +}
2914 +EXPORT_SYMBOL(wait_for_completion_killable);
2915 +
2916 +/**
2917 + * try_wait_for_completion - try to decrement a completion without blocking
2918 + * @x: completion structure
2919 + *
2920 + * Returns: 0 if a decrement cannot be done without blocking
2921 + * 1 if a decrement succeeded.
2922 + *
2923 + * If a completion is being used as a counting completion,
2924 + * attempt to decrement the counter without blocking. This
2925 + * enables us to avoid waiting if the resource the completion
2926 + * is protecting is not available.
2927 + */
2928 +bool try_wait_for_completion(struct completion *x)
2929 +{
2930 + int ret = 1;
2931 +
2932 + spin_lock_irq(&x->wait.lock);
2933 + if (!x->done)
2934 + ret = 0;
2935 + else
2936 + x->done--;
2937 + spin_unlock_irq(&x->wait.lock);
2938 + return ret;
2939 +}
2940 +EXPORT_SYMBOL(try_wait_for_completion);
2941 +
2942 +/**
2943 + * completion_done - Test to see if a completion has any waiters
2944 + * @x: completion structure
2945 + *
2946 + * Returns: 0 if there are waiters (wait_for_completion() in progress)
2947 + * 1 if there are no waiters.
2948 + *
2949 + */
2950 +bool completion_done(struct completion *x)
2951 +{
2952 + int ret = 1;
2953 +
2954 + spin_lock_irq(&x->wait.lock);
2955 + if (!x->done)
2956 + ret = 0;
2957 + spin_unlock_irq(&x->wait.lock);
2958 + return ret;
2959 +}
2960 +EXPORT_SYMBOL(completion_done);
2961 +
2962 +static long __sched
2963 +sleep_on_common(wait_queue_head_t *q, int state, long timeout)
2964 +{
2965 + unsigned long flags;
2966 + wait_queue_t wait;
2967 +
2968 + init_waitqueue_entry(&wait, current);
2969 +
2970 + __set_current_state(state);
2971 +
2972 + spin_lock_irqsave(&q->lock, flags);
2973 + __add_wait_queue(q, &wait);
2974 + spin_unlock(&q->lock);
2975 + timeout = schedule_timeout(timeout);
2976 + spin_lock_irq(&q->lock);
2977 + __remove_wait_queue(q, &wait);
2978 + spin_unlock_irqrestore(&q->lock, flags);
2979 +
2980 + return timeout;
2981 +}
2982 +
2983 +void __sched interruptible_sleep_on(wait_queue_head_t *q)
2984 +{
2985 + sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
2986 +}
2987 +EXPORT_SYMBOL(interruptible_sleep_on);
2988 +
2989 +long __sched
2990 +interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
2991 +{
2992 + return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
2993 +}
2994 +EXPORT_SYMBOL(interruptible_sleep_on_timeout);
2995 +
2996 +void __sched sleep_on(wait_queue_head_t *q)
2997 +{
2998 + sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
2999 +}
3000 +EXPORT_SYMBOL(sleep_on);
3001 +
3002 +long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
3003 +{
3004 + return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
3005 +}
3006 +EXPORT_SYMBOL(sleep_on_timeout);
3007 +
3008 +#ifdef CONFIG_RT_MUTEXES
3009 +
3010 +/*
3011 + * rt_mutex_setprio - set the current priority of a task
3012 + * @p: task
3013 + * @prio: prio value (kernel-internal form)
3014 + *
3015 + * This function changes the 'effective' priority of a task. It does
3016 + * not touch ->normal_prio like __setscheduler().
3017 + *
3018 + * Used by the rt_mutex code to implement priority inheritance logic.
3019 + */
3020 +void rt_mutex_setprio(struct task_struct *p, int prio)
3021 +{
3022 + unsigned long flags;
3023 + int queued, oldprio;
3024 + struct rq *rq;
3025 +
3026 + BUG_ON(prio < 0 || prio > MAX_PRIO);
3027 +
3028 + rq = time_task_grq_lock(p, &flags);
3029 +
3030 + oldprio = p->prio;
3031 + queued = task_queued_only(p);
3032 + if (queued)
3033 + dequeue_task(p);
3034 + p->prio = prio;
3035 + if (task_running(p) && prio > oldprio)
3036 + resched_task(p);
3037 + if (queued) {
3038 + enqueue_task(p);
3039 + try_preempt(p);
3040 + }
3041 +
3042 + task_grq_unlock(&flags);
3043 +}
3044 +
3045 +#endif
3046 +
3047 +/*
3048 + * Adjust the deadline for when the priority is to change, before it's
3049 + * changed.
3050 + */
3051 +static void adjust_deadline(struct task_struct *p, int new_prio)
3052 +{
3053 + p->deadline += (prio_ratios[USER_PRIO(new_prio)] - pratio(p)) *
3054 + rr_interval * HZ / 1000 / 100;
3055 +}
3056 +
3057 +void set_user_nice(struct task_struct *p, long nice)
3058 +{
3059 + int queued, new_static;
3060 + unsigned long flags;
3061 + struct rq *rq;
3062 +
3063 + if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
3064 + return;
3065 + new_static = NICE_TO_PRIO(nice);
3066 + /*
3067 + * We have to be careful, if called from sys_setpriority(),
3068 + * the task might be in the middle of scheduling on another CPU.
3069 + */
3070 + rq = time_task_grq_lock(p, &flags);
3071 + /*
3072 + * The RT priorities are set via sched_setscheduler(), but we still
3073 + * allow the 'normal' nice value to be set - but as expected
3074 + * it wont have any effect on scheduling until the task is
3075 + * not SCHED_NORMAL/SCHED_BATCH:
3076 + */
3077 + if (has_rt_policy(p)) {
3078 + p->static_prio = new_static;
3079 + goto out_unlock;
3080 + }
3081 + queued = task_queued_only(p);
3082 + /*
3083 + * If p is actually running, we don't need to do anything when
3084 + * changing the priority because the grq is unaffected.
3085 + */
3086 + if (queued)
3087 + dequeue_task(p);
3088 +
3089 + adjust_deadline(p, new_static);
3090 + p->static_prio = new_static;
3091 + p->prio = effective_prio(p);
3092 +
3093 + if (queued) {
3094 + enqueue_task(p);
3095 + try_preempt(p);
3096 + }
3097 +
3098 + /* Just resched the task, schedule() will know what to do. */
3099 + if (task_running(p))
3100 + resched_task(p);
3101 +out_unlock:
3102 + task_grq_unlock(&flags);
3103 +}
3104 +EXPORT_SYMBOL(set_user_nice);
3105 +
3106 +/*
3107 + * can_nice - check if a task can reduce its nice value
3108 + * @p: task
3109 + * @nice: nice value
3110 + */
3111 +int can_nice(const struct task_struct *p, const int nice)
3112 +{
3113 + /* convert nice value [19,-20] to rlimit style value [1,40] */
3114 + int nice_rlim = 20 - nice;
3115 +
3116 + return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
3117 + capable(CAP_SYS_NICE));
3118 +}
3119 +
3120 +#ifdef __ARCH_WANT_SYS_NICE
3121 +
3122 +/*
3123 + * sys_nice - change the priority of the current process.
3124 + * @increment: priority increment
3125 + *
3126 + * sys_setpriority is a more generic, but much slower function that
3127 + * does similar things.
3128 + */
3129 +SYSCALL_DEFINE1(nice, int, increment)
3130 +{
3131 + long nice, retval;
3132 +
3133 + /*
3134 + * Setpriority might change our priority at the same moment.
3135 + * We don't have to worry. Conceptually one call occurs first
3136 + * and we have a single winner.
3137 + */
3138 + if (increment < -40)
3139 + increment = -40;
3140 + if (increment > 40)
3141 + increment = 40;
3142 +
3143 + nice = TASK_NICE(current) + increment;
3144 + if (nice < -20)
3145 + nice = -20;
3146 + if (nice > 19)
3147 + nice = 19;
3148 +
3149 + if (increment < 0 && !can_nice(current, nice))
3150 + return -EPERM;
3151 +
3152 + retval = security_task_setnice(current, nice);
3153 + if (retval)
3154 + return retval;
3155 +
3156 + set_user_nice(current, nice);
3157 + return 0;
3158 +}
3159 +
3160 +#endif
3161 +
3162 +/**
3163 + * task_prio - return the priority value of a given task.
3164 + * @p: the task in question.
3165 + *
3166 + * This is the priority value as seen by users in /proc.
3167 + * RT tasks are offset by -100. Normal tasks are centered
3168 + * around 1, value goes from 0 (SCHED_ISO) up to 82 (nice +19
3169 + * SCHED_IDLE).
3170 + */
3171 +int task_prio(const struct task_struct *p)
3172 +{
3173 + int delta, prio = p->prio - MAX_RT_PRIO;
3174 +
3175 + /* rt tasks and iso tasks */
3176 + if (prio <= 0)
3177 + goto out;
3178 +
3179 + delta = (p->deadline - jiffies) * 40 / longest_deadline();
3180 + if (delta > 0 && delta <= 80)
3181 + prio += delta;
3182 +out:
3183 + return prio;
3184 +}
3185 +
3186 +/**
3187 + * task_nice - return the nice value of a given task.
3188 + * @p: the task in question.
3189 + */
3190 +int task_nice(const struct task_struct *p)
3191 +{
3192 + return TASK_NICE(p);
3193 +}
3194 +EXPORT_SYMBOL_GPL(task_nice);
3195 +
3196 +/**
3197 + * idle_cpu - is a given cpu idle currently?
3198 + * @cpu: the processor in question.
3199 + */
3200 +int idle_cpu(int cpu)
3201 +{
3202 + return cpu_curr(cpu) == cpu_rq(cpu)->idle;
3203 +}
3204 +
3205 +/**
3206 + * idle_task - return the idle task for a given cpu.
3207 + * @cpu: the processor in question.
3208 + */
3209 +struct task_struct *idle_task(int cpu)
3210 +{
3211 + return cpu_rq(cpu)->idle;
3212 +}
3213 +
3214 +/**
3215 + * find_process_by_pid - find a process with a matching PID value.
3216 + * @pid: the pid in question.
3217 + */
3218 +static inline struct task_struct *find_process_by_pid(pid_t pid)
3219 +{
3220 + return pid ? find_task_by_vpid(pid) : current;
3221 +}
3222 +
3223 +/* Actually do priority change: must hold grq lock. */
3224 +static void __setscheduler(struct task_struct *p, int policy, int prio)
3225 +{
3226 + BUG_ON(task_queued_only(p));
3227 +
3228 + p->policy = policy;
3229 + p->rt_priority = prio;
3230 + p->normal_prio = normal_prio(p);
3231 + /* we are holding p->pi_lock already */
3232 + p->prio = rt_mutex_getprio(p);
3233 + /*
3234 + * Reschedule if running. schedule() will know if it can continue
3235 + * running or not.
3236 + */
3237 + if (task_running(p))
3238 + resched_task(p);
3239 +}
3240 +
3241 +/*
3242 + * check the target process has a UID that matches the current process's
3243 + */
3244 +static bool check_same_owner(struct task_struct *p)
3245 +{
3246 + const struct cred *cred = current_cred(), *pcred;
3247 + bool match;
3248 +
3249 + rcu_read_lock();
3250 + pcred = __task_cred(p);
3251 + match = (cred->euid == pcred->euid ||
3252 + cred->euid == pcred->uid);
3253 + rcu_read_unlock();
3254 + return match;
3255 +}
3256 +
3257 +static int __sched_setscheduler(struct task_struct *p, int policy,
3258 + struct sched_param *param, bool user)
3259 +{
3260 + struct sched_param zero_param = { .sched_priority = 0 };
3261 + int queued, retval, oldprio, oldpolicy = -1;
3262 + unsigned long flags, rlim_rtprio = 0;
3263 + struct rq *rq;
3264 +
3265 + /* may grab non-irq protected spin_locks */
3266 + BUG_ON(in_interrupt());
3267 +
3268 + if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) {
3269 + unsigned long lflags;
3270 +
3271 + if (!lock_task_sighand(p, &lflags))
3272 + return -ESRCH;
3273 + rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
3274 + unlock_task_sighand(p, &lflags);
3275 + if (rlim_rtprio)
3276 + goto recheck;
3277 + /*
3278 + * If the caller requested an RT policy without having the
3279 + * necessary rights, we downgrade the policy to SCHED_ISO.
3280 + * We also set the parameter to zero to pass the checks.
3281 + */
3282 + policy = SCHED_ISO;
3283 + param = &zero_param;
3284 + }
3285 +recheck:
3286 + /* double check policy once rq lock held */
3287 + if (policy < 0)
3288 + policy = oldpolicy = p->policy;
3289 + else if (!SCHED_RANGE(policy))
3290 + return -EINVAL;
3291 + /*
3292 + * Valid priorities for SCHED_FIFO and SCHED_RR are
3293 + * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
3294 + * SCHED_BATCH is 0.
3295 + */
3296 + if (param->sched_priority < 0 ||
3297 + (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
3298 + (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
3299 + return -EINVAL;
3300 + if (is_rt_policy(policy) != (param->sched_priority != 0))
3301 + return -EINVAL;
3302 +
3303 + /*
3304 + * Allow unprivileged RT tasks to decrease priority:
3305 + */
3306 + if (user && !capable(CAP_SYS_NICE)) {
3307 + if (is_rt_policy(policy)) {
3308 + /* can't set/change the rt policy */
3309 + if (policy != p->policy && !rlim_rtprio)
3310 + return -EPERM;
3311 +
3312 + /* can't increase priority */
3313 + if (param->sched_priority > p->rt_priority &&
3314 + param->sched_priority > rlim_rtprio)
3315 + return -EPERM;
3316 + } else {
3317 + switch (p->policy) {
3318 + /*
3319 + * Can only downgrade policies but not back to
3320 + * SCHED_NORMAL
3321 + */
3322 + case SCHED_ISO:
3323 + if (policy == SCHED_ISO)
3324 + goto out;
3325 + if (policy == SCHED_NORMAL)
3326 + return -EPERM;
3327 + break;
3328 + case SCHED_BATCH:
3329 + if (policy == SCHED_BATCH)
3330 + goto out;
3331 + if (policy != SCHED_IDLE)
3332 + return -EPERM;
3333 + break;
3334 + case SCHED_IDLE:
3335 + if (policy == SCHED_IDLE)
3336 + goto out;
3337 + return -EPERM;
3338 + default:
3339 + break;
3340 + }
3341 + }
3342 +
3343 + /* can't change other user's priorities */
3344 + if (!check_same_owner(p))
3345 + return -EPERM;
3346 + }
3347 +
3348 + retval = security_task_setscheduler(p, policy, param);
3349 + if (retval)
3350 + return retval;
3351 + /*
3352 + * make sure no PI-waiters arrive (or leave) while we are
3353 + * changing the priority of the task:
3354 + */
3355 + spin_lock_irqsave(&p->pi_lock, flags);
3356 + /*
3357 + * To be able to change p->policy safely, the apropriate
3358 + * runqueue lock must be held.
3359 + */
3360 + rq = __task_grq_lock(p);
3361 + /* recheck policy now with rq lock held */
3362 + if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
3363 + __task_grq_unlock();
3364 + spin_unlock_irqrestore(&p->pi_lock, flags);
3365 + policy = oldpolicy = -1;
3366 + goto recheck;
3367 + }
3368 + update_rq_clock(rq);
3369 + queued = task_queued_only(p);
3370 + if (queued)
3371 + dequeue_task(p);
3372 + oldprio = p->prio;
3373 + __setscheduler(p, policy, param->sched_priority);
3374 + if (queued) {
3375 + enqueue_task(p);
3376 + try_preempt(p);
3377 + }
3378 + __task_grq_unlock();
3379 + spin_unlock_irqrestore(&p->pi_lock, flags);
3380 +
3381 + rt_mutex_adjust_pi(p);
3382 +out:
3383 + return 0;
3384 +}
3385 +
3386 +/**
3387 + * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
3388 + * @p: the task in question.
3389 + * @policy: new policy.
3390 + * @param: structure containing the new RT priority.
3391 + *
3392 + * NOTE that the task may be already dead.
3393 + */
3394 +int sched_setscheduler(struct task_struct *p, int policy,
3395 + struct sched_param *param)
3396 +{
3397 + return __sched_setscheduler(p, policy, param, true);
3398 +}
3399 +
3400 +EXPORT_SYMBOL_GPL(sched_setscheduler);
3401 +
3402 +/**
3403 + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
3404 + * @p: the task in question.
3405 + * @policy: new policy.
3406 + * @param: structure containing the new RT priority.
3407 + *
3408 + * Just like sched_setscheduler, only don't bother checking if the
3409 + * current context has permission. For example, this is needed in
3410 + * stop_machine(): we create temporary high priority worker threads,
3411 + * but our caller might not have that capability.
3412 + */
3413 +int sched_setscheduler_nocheck(struct task_struct *p, int policy,
3414 + struct sched_param *param)
3415 +{
3416 + return __sched_setscheduler(p, policy, param, false);
3417 +}
3418 +
3419 +static int
3420 +do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
3421 +{
3422 + struct sched_param lparam;
3423 + struct task_struct *p;
3424 + int retval;
3425 +
3426 + if (!param || pid < 0)
3427 + return -EINVAL;
3428 + if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
3429 + return -EFAULT;
3430 +
3431 + rcu_read_lock();
3432 + retval = -ESRCH;
3433 + p = find_process_by_pid(pid);
3434 + if (p != NULL)
3435 + retval = sched_setscheduler(p, policy, &lparam);
3436 + rcu_read_unlock();
3437 +
3438 + return retval;
3439 +}
3440 +
3441 +/**
3442 + * sys_sched_setscheduler - set/change the scheduler policy and RT priority
3443 + * @pid: the pid in question.
3444 + * @policy: new policy.
3445 + * @param: structure containing the new RT priority.
3446 + */
3447 +asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
3448 + struct sched_param __user *param)
3449 +{
3450 + /* negative values for policy are not valid */
3451 + if (policy < 0)
3452 + return -EINVAL;
3453 +
3454 + return do_sched_setscheduler(pid, policy, param);
3455 +}
3456 +
3457 +/**
3458 + * sys_sched_setparam - set/change the RT priority of a thread
3459 + * @pid: the pid in question.
3460 + * @param: structure containing the new RT priority.
3461 + */
3462 +SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
3463 +{
3464 + return do_sched_setscheduler(pid, -1, param);
3465 +}
3466 +
3467 +/**
3468 + * sys_sched_getscheduler - get the policy (scheduling class) of a thread
3469 + * @pid: the pid in question.
3470 + */
3471 +SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
3472 +{
3473 + struct task_struct *p;
3474 + int retval = -EINVAL;
3475 +
3476 + if (pid < 0)
3477 + goto out_nounlock;
3478 +
3479 + retval = -ESRCH;
3480 + read_lock(&tasklist_lock);
3481 + p = find_process_by_pid(pid);
3482 + if (p) {
3483 + retval = security_task_getscheduler(p);
3484 + if (!retval)
3485 + retval = p->policy;
3486 + }
3487 + read_unlock(&tasklist_lock);
3488 +
3489 +out_nounlock:
3490 + return retval;
3491 +}
3492 +
3493 +/**
3494 + * sys_sched_getscheduler - get the RT priority of a thread
3495 + * @pid: the pid in question.
3496 + * @param: structure containing the RT priority.
3497 + */
3498 +SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
3499 +{
3500 + struct sched_param lp;
3501 + struct task_struct *p;
3502 + int retval = -EINVAL;
3503 +
3504 + if (!param || pid < 0)
3505 + goto out_nounlock;
3506 +
3507 + read_lock(&tasklist_lock);
3508 + p = find_process_by_pid(pid);
3509 + retval = -ESRCH;
3510 + if (!p)
3511 + goto out_unlock;
3512 +
3513 + retval = security_task_getscheduler(p);
3514 + if (retval)
3515 + goto out_unlock;
3516 +
3517 + lp.sched_priority = p->rt_priority;
3518 + read_unlock(&tasklist_lock);
3519 +
3520 + /*
3521 + * This one might sleep, we cannot do it with a spinlock held ...
3522 + */
3523 + retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
3524 +
3525 +out_nounlock:
3526 + return retval;
3527 +
3528 +out_unlock:
3529 + read_unlock(&tasklist_lock);
3530 + return retval;
3531 +}
3532 +
3533 +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
3534 +{
3535 + cpumask_var_t cpus_allowed, new_mask;
3536 + struct task_struct *p;
3537 + int retval;
3538 +
3539 + get_online_cpus();
3540 + read_lock(&tasklist_lock);
3541 +
3542 + p = find_process_by_pid(pid);
3543 + if (!p) {
3544 + read_unlock(&tasklist_lock);
3545 + put_online_cpus();
3546 + return -ESRCH;
3547 + }
3548 +
3549 + /*
3550 + * It is not safe to call set_cpus_allowed with the
3551 + * tasklist_lock held. We will bump the task_struct's
3552 + * usage count and then drop tasklist_lock.
3553 + */
3554 + get_task_struct(p);
3555 + read_unlock(&tasklist_lock);
3556 +
3557 + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
3558 + retval = -ENOMEM;
3559 + goto out_put_task;
3560 + }
3561 + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
3562 + retval = -ENOMEM;
3563 + goto out_free_cpus_allowed;
3564 + }
3565 + retval = -EPERM;
3566 + if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
3567 + goto out_unlock;
3568 +
3569 + retval = security_task_setscheduler(p, 0, NULL);
3570 + if (retval)
3571 + goto out_unlock;
3572 +
3573 + cpuset_cpus_allowed(p, cpus_allowed);
3574 + cpumask_and(new_mask, in_mask, cpus_allowed);
3575 +again:
3576 + retval = set_cpus_allowed_ptr(p, new_mask);
3577 +
3578 + if (!retval) {
3579 + cpuset_cpus_allowed(p, cpus_allowed);
3580 + if (!cpumask_subset(new_mask, cpus_allowed)) {
3581 + /*
3582 + * We must have raced with a concurrent cpuset
3583 + * update. Just reset the cpus_allowed to the
3584 + * cpuset's cpus_allowed
3585 + */
3586 + cpumask_copy(new_mask, cpus_allowed);
3587 + goto again;
3588 + }
3589 + }
3590 +out_unlock:
3591 + free_cpumask_var(new_mask);
3592 +out_free_cpus_allowed:
3593 + free_cpumask_var(cpus_allowed);
3594 +out_put_task:
3595 + put_task_struct(p);
3596 + put_online_cpus();
3597 + return retval;
3598 +}
3599 +
3600 +static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
3601 + cpumask_t *new_mask)
3602 +{
3603 + if (len < sizeof(cpumask_t)) {
3604 + memset(new_mask, 0, sizeof(cpumask_t));
3605 + } else if (len > sizeof(cpumask_t)) {
3606 + len = sizeof(cpumask_t);
3607 + }
3608 + return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
3609 +}
3610 +
3611 +
3612 +/**
3613 + * sys_sched_setaffinity - set the cpu affinity of a process
3614 + * @pid: pid of the process
3615 + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
3616 + * @user_mask_ptr: user-space pointer to the new cpu mask
3617 + */
3618 +SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
3619 + unsigned long __user *, user_mask_ptr)
3620 +{
3621 + cpumask_var_t new_mask;
3622 + int retval;
3623 +
3624 + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
3625 + return -ENOMEM;
3626 +
3627 + retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
3628 + if (retval == 0)
3629 + retval = sched_setaffinity(pid, new_mask);
3630 + free_cpumask_var(new_mask);
3631 + return retval;
3632 +}
3633 +
3634 +long sched_getaffinity(pid_t pid, cpumask_t *mask)
3635 +{
3636 + struct task_struct *p;
3637 + int retval;
3638 +
3639 + mutex_lock(&sched_hotcpu_mutex);
3640 + read_lock(&tasklist_lock);
3641 +
3642 + retval = -ESRCH;
3643 + p = find_process_by_pid(pid);
3644 + if (!p)
3645 + goto out_unlock;
3646 +
3647 + retval = security_task_getscheduler(p);
3648 + if (retval)
3649 + goto out_unlock;
3650 +
3651 + cpus_and(*mask, p->cpus_allowed, cpu_online_map);
3652 +
3653 +out_unlock:
3654 + read_unlock(&tasklist_lock);
3655 + mutex_unlock(&sched_hotcpu_mutex);
3656 + if (retval)
3657 + return retval;
3658 +
3659 + return 0;
3660 +}
3661 +
3662 +/**
3663 + * sys_sched_getaffinity - get the cpu affinity of a process
3664 + * @pid: pid of the process
3665 + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
3666 + * @user_mask_ptr: user-space pointer to hold the current cpu mask
3667 + */
3668 +SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
3669 + unsigned long __user *, user_mask_ptr)
3670 +{
3671 + int ret;
3672 + cpumask_var_t mask;
3673 +
3674 + if (len < cpumask_size())
3675 + return -EINVAL;
3676 +
3677 + if (!alloc_cpumask_var(&mask, GFP_KERNEL))
3678 + return -ENOMEM;
3679 +
3680 + ret = sched_getaffinity(pid, mask);
3681 + if (ret == 0) {
3682 + if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
3683 + ret = -EFAULT;
3684 + else
3685 + ret = cpumask_size();
3686 + }
3687 + free_cpumask_var(mask);
3688 +
3689 + return ret;
3690 +}
3691 +
3692 +/**
3693 + * sys_sched_yield - yield the current processor to other threads.
3694 + *
3695 + * This function yields the current CPU to other tasks. It does this by
3696 + * refilling the timeslice, resetting the deadline and scheduling away.
3697 + */
3698 +SYSCALL_DEFINE0(sched_yield)
3699 +{
3700 + struct task_struct *p;
3701 +
3702 + grq_lock_irq();
3703 + p = current;
3704 + schedstat_inc(this_rq(), yld_count);
3705 + update_rq_clock(task_rq(p));
3706 + time_slice_expired(p);
3707 + requeue_task(p);
3708 +
3709 + /*
3710 + * Since we are going to call schedule() anyway, there's
3711 + * no need to preempt or enable interrupts:
3712 + */
3713 + __release(grq.lock);
3714 + spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
3715 + _raw_spin_unlock(&grq.lock);
3716 + preempt_enable_no_resched();
3717 +
3718 + schedule();
3719 +
3720 + return 0;
3721 +}
3722 +
3723 +static inline int should_resched(void)
3724 +{
3725 + return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
3726 +}
3727 +
3728 +static void __cond_resched(void)
3729 +{
3730 +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
3731 + __might_sleep(__FILE__, __LINE__);
3732 +#endif
3733 + /*
3734 + * The BKS might be reacquired before we have dropped
3735 + * PREEMPT_ACTIVE, which could trigger a second
3736 + * cond_resched() call.
3737 + */
3738 + do {
3739 + add_preempt_count(PREEMPT_ACTIVE);
3740 + schedule();
3741 + sub_preempt_count(PREEMPT_ACTIVE);
3742 + } while (need_resched());
3743 +}
3744 +
3745 +int __sched _cond_resched(void)
3746 +{
3747 + if (should_resched()) {
3748 + __cond_resched();
3749 + return 1;
3750 + }
3751 + return 0;
3752 +}
3753 +EXPORT_SYMBOL(_cond_resched);
3754 +
3755 +/*
3756 + * cond_resched_lock() - if a reschedule is pending, drop the given lock,
3757 + * call schedule, and on return reacquire the lock.
3758 + *
3759 + * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
3760 + * operations here to prevent schedule() from being called twice (once via
3761 + * spin_unlock(), once by hand).
3762 + */
3763 +int cond_resched_lock(spinlock_t *lock)
3764 +{
3765 + int resched = should_resched();
3766 + int ret = 0;
3767 +
3768 + if (spin_needbreak(lock) || resched) {
3769 + spin_unlock(lock);
3770 + if (resched)
3771 + __cond_resched();
3772 + else
3773 + cpu_relax();
3774 + ret = 1;
3775 + spin_lock(lock);
3776 + }
3777 + return ret;
3778 +}
3779 +EXPORT_SYMBOL(cond_resched_lock);
3780 +
3781 +int __sched cond_resched_softirq(void)
3782 +{
3783 + BUG_ON(!in_softirq());
3784 +
3785 + if (should_resched()) {
3786 + local_bh_enable();
3787 + __cond_resched();
3788 + local_bh_disable();
3789 + return 1;
3790 + }
3791 + return 0;
3792 +}
3793 +EXPORT_SYMBOL(cond_resched_softirq);
3794 +
3795 +/**
3796 + * yield - yield the current processor to other threads.
3797 + *
3798 + * This is a shortcut for kernel-space yielding - it marks the
3799 + * thread runnable and calls sys_sched_yield().
3800 + */
3801 +void __sched yield(void)
3802 +{
3803 + set_current_state(TASK_RUNNING);
3804 + sys_sched_yield();
3805 +}
3806 +EXPORT_SYMBOL(yield);
3807 +
3808 +/*
3809 + * This task is about to go to sleep on IO. Increment rq->nr_iowait so
3810 + * that process accounting knows that this is a task in IO wait state.
3811 + *
3812 + * But don't do that if it is a deliberate, throttling IO wait (this task
3813 + * has set its backing_dev_info: the queue against which it should throttle)
3814 + */
3815 +void __sched io_schedule(void)
3816 +{
3817 + struct rq *rq = &__raw_get_cpu_var(runqueues);
3818 +
3819 + delayacct_blkio_start();
3820 + atomic_inc(&rq->nr_iowait);
3821 + schedule();
3822 + atomic_dec(&rq->nr_iowait);
3823 + delayacct_blkio_end();
3824 +}
3825 +EXPORT_SYMBOL(io_schedule);
3826 +
3827 +long __sched io_schedule_timeout(long timeout)
3828 +{
3829 + struct rq *rq = &__raw_get_cpu_var(runqueues);
3830 + long ret;
3831 +
3832 + delayacct_blkio_start();
3833 + atomic_inc(&rq->nr_iowait);
3834 + ret = schedule_timeout(timeout);
3835 + atomic_dec(&rq->nr_iowait);
3836 + delayacct_blkio_end();
3837 + return ret;
3838 +}
3839 +
3840 +/**
3841 + * sys_sched_get_priority_max - return maximum RT priority.
3842 + * @policy: scheduling class.
3843 + *
3844 + * this syscall returns the maximum rt_priority that can be used
3845 + * by a given scheduling class.
3846 + */
3847 +SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
3848 +{
3849 + int ret = -EINVAL;
3850 +
3851 + switch (policy) {
3852 + case SCHED_FIFO:
3853 + case SCHED_RR:
3854 + ret = MAX_USER_RT_PRIO-1;
3855 + break;
3856 + case SCHED_NORMAL:
3857 + case SCHED_BATCH:
3858 + case SCHED_ISO:
3859 + case SCHED_IDLE:
3860 + ret = 0;
3861 + break;
3862 + }
3863 + return ret;
3864 +}
3865 +
3866 +/**
3867 + * sys_sched_get_priority_min - return minimum RT priority.
3868 + * @policy: scheduling class.
3869 + *
3870 + * this syscall returns the minimum rt_priority that can be used
3871 + * by a given scheduling class.
3872 + */
3873 +SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
3874 +{
3875 + int ret = -EINVAL;
3876 +
3877 + switch (policy) {
3878 + case SCHED_FIFO:
3879 + case SCHED_RR:
3880 + ret = 1;
3881 + break;
3882 + case SCHED_NORMAL:
3883 + case SCHED_BATCH:
3884 + case SCHED_ISO:
3885 + case SCHED_IDLE:
3886 + ret = 0;
3887 + break;
3888 + }
3889 + return ret;
3890 +}
3891 +
3892 +/**
3893 + * sys_sched_rr_get_interval - return the default timeslice of a process.
3894 + * @pid: pid of the process.
3895 + * @interval: userspace pointer to the timeslice value.
3896 + *
3897 + * this syscall writes the default timeslice value of a given process
3898 + * into the user-space timespec buffer. A value of '0' means infinity.
3899 + */
3900 +SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
3901 + struct timespec __user *, interval)
3902 +{
3903 + struct task_struct *p;
3904 + int retval = -EINVAL;
3905 + struct timespec t;
3906 +
3907 + if (pid < 0)
3908 + goto out_nounlock;
3909 +
3910 + retval = -ESRCH;
3911 + read_lock(&tasklist_lock);
3912 + p = find_process_by_pid(pid);
3913 + if (!p)
3914 + goto out_unlock;
3915 +
3916 + retval = security_task_getscheduler(p);
3917 + if (retval)
3918 + goto out_unlock;
3919 +
3920 + t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
3921 + MS_TO_NS(task_timeslice(p)));
3922 + read_unlock(&tasklist_lock);
3923 + retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
3924 +out_nounlock:
3925 + return retval;
3926 +out_unlock:
3927 + read_unlock(&tasklist_lock);
3928 + return retval;
3929 +}
3930 +
3931 +static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
3932 +
3933 +void sched_show_task(struct task_struct *p)
3934 +{
3935 + unsigned long free = 0;
3936 + unsigned state;
3937 +
3938 + state = p->state ? __ffs(p->state) + 1 : 0;
3939 + printk(KERN_INFO "%-13.13s %c", p->comm,
3940 + state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
3941 +#if BITS_PER_LONG == 32
3942 + if (state == TASK_RUNNING)
3943 + printk(KERN_CONT " running ");
3944 + else
3945 + printk(KERN_CONT " %08lx ", thread_saved_pc(p));
3946 +#else
3947 + if (state == TASK_RUNNING)
3948 + printk(KERN_CONT " running task ");
3949 + else
3950 + printk(KERN_CONT " %016lx ", thread_saved_pc(p));
3951 +#endif
3952 +#ifdef CONFIG_DEBUG_STACK_USAGE
3953 + free = stack_not_used(p);
3954 +#endif
3955 + printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
3956 + task_pid_nr(p), task_pid_nr(p->real_parent),
3957 + (unsigned long)task_thread_info(p)->flags);
3958 +
3959 + show_stack(p, NULL);
3960 +}
3961 +
3962 +void show_state_filter(unsigned long state_filter)
3963 +{
3964 + struct task_struct *g, *p;
3965 +
3966 +#if BITS_PER_LONG == 32
3967 + printk(KERN_INFO
3968 + " task PC stack pid father\n");
3969 +#else
3970 + printk(KERN_INFO
3971 + " task PC stack pid father\n");
3972 +#endif
3973 + read_lock(&tasklist_lock);
3974 + do_each_thread(g, p) {
3975 + /*
3976 + * reset the NMI-timeout, listing all files on a slow
3977 + * console might take alot of time:
3978 + */
3979 + touch_nmi_watchdog();
3980 + if (!state_filter || (p->state & state_filter))
3981 + sched_show_task(p);
3982 + } while_each_thread(g, p);
3983 +
3984 + touch_all_softlockup_watchdogs();
3985 +
3986 + read_unlock(&tasklist_lock);
3987 + /*
3988 + * Only show locks if all tasks are dumped:
3989 + */
3990 + if (state_filter == -1)
3991 + debug_show_all_locks();
3992 +}
3993 +
3994 +/**
3995 + * init_idle - set up an idle thread for a given CPU
3996 + * @idle: task in question
3997 + * @cpu: cpu the idle task belongs to
3998 + *
3999 + * NOTE: this function does not set the idle thread's NEED_RESCHED
4000 + * flag, to make booting more robust.
4001 + */
4002 +void __cpuinit init_idle(struct task_struct *idle, int cpu)
4003 +{
4004 + struct rq *rq = cpu_rq(cpu);
4005 + unsigned long flags;
4006 +
4007 + time_grq_lock(rq, &flags);
4008 + idle->timestamp = idle->last_ran = rq->clock;
4009 + idle->state = TASK_RUNNING;
4010 + /* Setting prio to illegal value shouldn't matter when never queued */
4011 + idle->prio = rq->rq_prio = PRIO_LIMIT;
4012 + rq->rq_deadline = idle->deadline;
4013 + rq->rq_policy = idle->policy;
4014 + rq->rq_time_slice = idle->rt.time_slice;
4015 + idle->cpus_allowed = cpumask_of_cpu(cpu);
4016 + set_task_cpu(idle, cpu);
4017 + rq->curr = rq->idle = idle;
4018 + idle->oncpu = 1;
4019 + set_cpuidle_map(cpu);
4020 +#ifdef CONFIG_HOTPLUG_CPU
4021 + idle->unplugged_mask = CPU_MASK_NONE;
4022 +#endif
4023 + grq_unlock_irqrestore(&flags);
4024 +
4025 + /* Set the preempt count _outside_ the spinlocks! */
4026 +#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
4027 + task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
4028 +#else
4029 + task_thread_info(idle)->preempt_count = 0;
4030 +#endif
4031 + ftrace_graph_init_task(idle);
4032 +}
4033 +
4034 +/*
4035 + * In a system that switches off the HZ timer nohz_cpu_mask
4036 + * indicates which cpus entered this state. This is used
4037 + * in the rcu update to wait only for active cpus. For system
4038 + * which do not switch off the HZ timer nohz_cpu_mask should
4039 + * always be CPU_BITS_NONE.
4040 + */
4041 +cpumask_var_t nohz_cpu_mask;
4042 +
4043 +#ifdef CONFIG_SMP
4044 +#ifdef CONFIG_NO_HZ
4045 +static struct {
4046 + atomic_t load_balancer;
4047 + cpumask_var_t cpu_mask;
4048 + cpumask_var_t ilb_grp_nohz_mask;
4049 +} nohz ____cacheline_aligned = {
4050 + .load_balancer = ATOMIC_INIT(-1),
4051 +};
4052 +
4053 +int get_nohz_load_balancer(void)
4054 +{
4055 + return atomic_read(&nohz.load_balancer);
4056 +}
4057 +
4058 +/*
4059 + * This routine will try to nominate the ilb (idle load balancing)
4060 + * owner among the cpus whose ticks are stopped. ilb owner will do the idle
4061 + * load balancing on behalf of all those cpus. If all the cpus in the system
4062 + * go into this tickless mode, then there will be no ilb owner (as there is
4063 + * no need for one) and all the cpus will sleep till the next wakeup event
4064 + * arrives...
4065 + *
4066 + * For the ilb owner, tick is not stopped. And this tick will be used
4067 + * for idle load balancing. ilb owner will still be part of
4068 + * nohz.cpu_mask..
4069 + *
4070 + * While stopping the tick, this cpu will become the ilb owner if there
4071 + * is no other owner. And will be the owner till that cpu becomes busy
4072 + * or if all cpus in the system stop their ticks at which point
4073 + * there is no need for ilb owner.
4074 + *
4075 + * When the ilb owner becomes busy, it nominates another owner, during the
4076 + * next busy scheduler_tick()
4077 + */
4078 +int select_nohz_load_balancer(int stop_tick)
4079 +{
4080 + int cpu = smp_processor_id();
4081 +
4082 + if (stop_tick) {
4083 + cpu_rq(cpu)->in_nohz_recently = 1;
4084 +
4085 + if (!cpu_active(cpu)) {
4086 + if (atomic_read(&nohz.load_balancer) != cpu)
4087 + return 0;
4088 +
4089 + /*
4090 + * If we are going offline and still the leader,
4091 + * give up!
4092 + */
4093 + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
4094 + BUG();
4095 +
4096 + return 0;
4097 + }
4098 +
4099 + cpumask_set_cpu(cpu, nohz.cpu_mask);
4100 +
4101 + /* time for ilb owner also to sleep */
4102 + if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
4103 + if (atomic_read(&nohz.load_balancer) == cpu)
4104 + atomic_set(&nohz.load_balancer, -1);
4105 + return 0;
4106 + }
4107 +
4108 + if (atomic_read(&nohz.load_balancer) == -1) {
4109 + /* make me the ilb owner */
4110 + if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
4111 + return 1;
4112 + } else if (atomic_read(&nohz.load_balancer) == cpu)
4113 + return 1;
4114 + } else {
4115 + if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
4116 + return 0;
4117 +
4118 + cpumask_clear_cpu(cpu, nohz.cpu_mask);
4119 +
4120 + if (atomic_read(&nohz.load_balancer) == cpu)
4121 + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
4122 + BUG();
4123 + }
4124 + return 0;
4125 +}
4126 +
4127 +/*
4128 + * When add_timer_on() enqueues a timer into the timer wheel of an
4129 + * idle CPU then this timer might expire before the next timer event
4130 + * which is scheduled to wake up that CPU. In case of a completely
4131 + * idle system the next event might even be infinite time into the
4132 + * future. wake_up_idle_cpu() ensures that the CPU is woken up and
4133 + * leaves the inner idle loop so the newly added timer is taken into
4134 + * account when the CPU goes back to idle and evaluates the timer
4135 + * wheel for the next timer event.
4136 + */
4137 +void wake_up_idle_cpu(int cpu)
4138 +{
4139 + struct task_struct *idle;
4140 + struct rq *rq;
4141 +
4142 + if (cpu == smp_processor_id())
4143 + return;
4144 +
4145 + rq = cpu_rq(cpu);
4146 + idle = rq->idle;
4147 +
4148 + /*
4149 + * This is safe, as this function is called with the timer
4150 + * wheel base lock of (cpu) held. When the CPU is on the way
4151 + * to idle and has not yet set rq->curr to idle then it will
4152 + * be serialized on the timer wheel base lock and take the new
4153 + * timer into account automatically.
4154 + */
4155 + if (unlikely(rq->curr != idle))
4156 + return;
4157 +
4158 + /*
4159 + * We can set TIF_RESCHED on the idle task of the other CPU
4160 + * lockless. The worst case is that the other CPU runs the
4161 + * idle task through an additional NOOP schedule()
4162 + */
4163 + set_tsk_need_resched(idle);
4164 +
4165 + /* NEED_RESCHED must be visible before we test polling */
4166 + smp_mb();
4167 + if (!tsk_is_polling(idle))
4168 + smp_send_reschedule(cpu);
4169 +}
4170 +
4171 +#endif /* CONFIG_NO_HZ */
4172 +
4173 +/*
4174 + * Change a given task's CPU affinity. Migrate the thread to a
4175 + * proper CPU and schedule it away if the CPU it's executing on
4176 + * is removed from the allowed bitmask.
4177 + *
4178 + * NOTE: the caller must have a valid reference to the task, the
4179 + * task must not exit() & deallocate itself prematurely. The
4180 + * call is not atomic; no spinlocks may be held.
4181 + */
4182 +int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
4183 +{
4184 + unsigned long flags;
4185 + int running = 0;
4186 + int queued = 0;
4187 + struct rq *rq;
4188 + int ret = 0;
4189 +
4190 + rq = task_grq_lock(p, &flags);
4191 + if (!cpumask_intersects(new_mask, cpu_online_mask)) {
4192 + ret = -EINVAL;
4193 + goto out;
4194 + }
4195 +
4196 + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
4197 + !cpumask_equal(&p->cpus_allowed, new_mask))) {
4198 + ret = -EINVAL;
4199 + goto out;
4200 + }
4201 +
4202 + queued = task_queued_only(p);
4203 +
4204 + cpumask_copy(&p->cpus_allowed, new_mask);
4205 + p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
4206 +
4207 + /* Can the task run on the task's current CPU? If so, we're done */
4208 + if (cpumask_test_cpu(task_cpu(p), new_mask))
4209 + goto out;
4210 +
4211 + /* Reschedule the task, schedule() will know if it can keep running */
4212 + if (task_running(p))
4213 + running = 1;
4214 + else
4215 + set_task_cpu(p, cpumask_any_and(cpu_online_mask, new_mask));
4216 +
4217 +out:
4218 + if (queued)
4219 + try_preempt(p);
4220 + task_grq_unlock(&flags);
4221 +
4222 + /* This might be a flaky way of changing cpus! */
4223 + if (running)
4224 + schedule();
4225 + return ret;
4226 +}
4227 +EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
4228 +
4229 +#ifdef CONFIG_HOTPLUG_CPU
4230 +/* Schedules idle task to be the next runnable task on current CPU.
4231 + * It does so by boosting its priority to highest possible.
4232 + * Used by CPU offline code.
4233 + */
4234 +void sched_idle_next(void)
4235 +{
4236 + int this_cpu = smp_processor_id();
4237 + struct rq *rq = cpu_rq(this_cpu);
4238 + struct task_struct *idle = rq->idle;
4239 + unsigned long flags;
4240 +
4241 + /* cpu has to be offline */
4242 + BUG_ON(cpu_online(this_cpu));
4243 +
4244 + /*
4245 + * Strictly not necessary since rest of the CPUs are stopped by now
4246 + * and interrupts disabled on the current cpu.
4247 + */
4248 + time_grq_lock(rq, &flags);
4249 +
4250 + __setscheduler(idle, SCHED_FIFO, MAX_RT_PRIO - 1);
4251 +
4252 + activate_idle_task(idle);
4253 + set_tsk_need_resched(rq->curr);
4254 +
4255 + grq_unlock_irqrestore(&flags);
4256 +}
4257 +
4258 +/*
4259 + * Ensures that the idle task is using init_mm right before its cpu goes
4260 + * offline.
4261 + */
4262 +void idle_task_exit(void)
4263 +{
4264 + struct mm_struct *mm = current->active_mm;
4265 +
4266 + BUG_ON(cpu_online(smp_processor_id()));
4267 +
4268 + if (mm != &init_mm)
4269 + switch_mm(mm, &init_mm, current);
4270 + mmdrop(mm);
4271 +}
4272 +
4273 +#endif /* CONFIG_HOTPLUG_CPU */
4274 +
4275 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
4276 +
4277 +static struct ctl_table sd_ctl_dir[] = {
4278 + {
4279 + .procname = "sched_domain",
4280 + .mode = 0555,
4281 + },
4282 + {0, },
4283 +};
4284 +
4285 +static struct ctl_table sd_ctl_root[] = {
4286 + {
4287 + .ctl_name = CTL_KERN,
4288 + .procname = "kernel",
4289 + .mode = 0555,
4290 + .child = sd_ctl_dir,
4291 + },
4292 + {0, },
4293 +};
4294 +
4295 +static struct ctl_table *sd_alloc_ctl_entry(int n)
4296 +{
4297 + struct ctl_table *entry =
4298 + kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
4299 +
4300 + return entry;
4301 +}
4302 +
4303 +static void sd_free_ctl_entry(struct ctl_table **tablep)
4304 +{
4305 + struct ctl_table *entry;
4306 +
4307 + /*
4308 + * In the intermediate directories, both the child directory and
4309 + * procname are dynamically allocated and could fail but the mode
4310 + * will always be set. In the lowest directory the names are
4311 + * static strings and all have proc handlers.
4312 + */
4313 + for (entry = *tablep; entry->mode; entry++) {
4314 + if (entry->child)
4315 + sd_free_ctl_entry(&entry->child);
4316 + if (entry->proc_handler == NULL)
4317 + kfree(entry->procname);
4318 + }
4319 +
4320 + kfree(*tablep);
4321 + *tablep = NULL;
4322 +}
4323 +
4324 +static void
4325 +set_table_entry(struct ctl_table *entry,
4326 + const char *procname, void *data, int maxlen,
4327 + mode_t mode, proc_handler *proc_handler)
4328 +{
4329 + entry->procname = procname;
4330 + entry->data = data;
4331 + entry->maxlen = maxlen;
4332 + entry->mode = mode;
4333 + entry->proc_handler = proc_handler;
4334 +}
4335 +
4336 +static struct ctl_table *
4337 +sd_alloc_ctl_domain_table(struct sched_domain *sd)
4338 +{
4339 + struct ctl_table *table = sd_alloc_ctl_entry(13);
4340 +
4341 + if (table == NULL)
4342 + return NULL;
4343 +
4344 + set_table_entry(&table[0], "min_interval", &sd->min_interval,
4345 + sizeof(long), 0644, proc_doulongvec_minmax);
4346 + set_table_entry(&table[1], "max_interval", &sd->max_interval,
4347 + sizeof(long), 0644, proc_doulongvec_minmax);
4348 + set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
4349 + sizeof(int), 0644, proc_dointvec_minmax);
4350 + set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
4351 + sizeof(int), 0644, proc_dointvec_minmax);
4352 + set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
4353 + sizeof(int), 0644, proc_dointvec_minmax);
4354 + set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
4355 + sizeof(int), 0644, proc_dointvec_minmax);
4356 + set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
4357 + sizeof(int), 0644, proc_dointvec_minmax);
4358 + set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
4359 + sizeof(int), 0644, proc_dointvec_minmax);
4360 + set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
4361 + sizeof(int), 0644, proc_dointvec_minmax);
4362 + set_table_entry(&table[9], "cache_nice_tries",
4363 + &sd->cache_nice_tries,
4364 + sizeof(int), 0644, proc_dointvec_minmax);
4365 + set_table_entry(&table[10], "flags", &sd->flags,
4366 + sizeof(int), 0644, proc_dointvec_minmax);
4367 + set_table_entry(&table[11], "name", sd->name,
4368 + CORENAME_MAX_SIZE, 0444, proc_dostring);
4369 + /* &table[12] is terminator */
4370 +
4371 + return table;
4372 +}
4373 +
4374 +static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
4375 +{
4376 + struct ctl_table *entry, *table;
4377 + struct sched_domain *sd;
4378 + int domain_num = 0, i;
4379 + char buf[32];
4380 +
4381 + for_each_domain(cpu, sd)
4382 + domain_num++;
4383 + entry = table = sd_alloc_ctl_entry(domain_num + 1);
4384 + if (table == NULL)
4385 + return NULL;
4386 +
4387 + i = 0;
4388 + for_each_domain(cpu, sd) {
4389 + snprintf(buf, 32, "domain%d", i);
4390 + entry->procname = kstrdup(buf, GFP_KERNEL);
4391 + entry->mode = 0555;
4392 + entry->child = sd_alloc_ctl_domain_table(sd);
4393 + entry++;
4394 + i++;
4395 + }
4396 + return table;
4397 +}
4398 +
4399 +static struct ctl_table_header *sd_sysctl_header;
4400 +static void register_sched_domain_sysctl(void)
4401 +{
4402 + int i, cpu_num = num_online_cpus();
4403 + struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
4404 + char buf[32];
4405 +
4406 + WARN_ON(sd_ctl_dir[0].child);
4407 + sd_ctl_dir[0].child = entry;
4408 +
4409 + if (entry == NULL)
4410 + return;
4411 +
4412 + for_each_online_cpu(i) {
4413 + snprintf(buf, 32, "cpu%d", i);
4414 + entry->procname = kstrdup(buf, GFP_KERNEL);
4415 + entry->mode = 0555;
4416 + entry->child = sd_alloc_ctl_cpu_table(i);
4417 + entry++;
4418 + }
4419 +
4420 + WARN_ON(sd_sysctl_header);
4421 + sd_sysctl_header = register_sysctl_table(sd_ctl_root);
4422 +}
4423 +
4424 +/* may be called multiple times per register */
4425 +static void unregister_sched_domain_sysctl(void)
4426 +{
4427 + if (sd_sysctl_header)
4428 + unregister_sysctl_table(sd_sysctl_header);
4429 + sd_sysctl_header = NULL;
4430 + if (sd_ctl_dir[0].child)
4431 + sd_free_ctl_entry(&sd_ctl_dir[0].child);
4432 +}
4433 +#else
4434 +static void register_sched_domain_sysctl(void)
4435 +{
4436 +}
4437 +static void unregister_sched_domain_sysctl(void)
4438 +{
4439 +}
4440 +#endif
4441 +
4442 +static void set_rq_online(struct rq *rq)
4443 +{
4444 + if (!rq->online) {
4445 + cpumask_set_cpu(rq->cpu, rq->rd->online);
4446 + rq->online = 1;
4447 + }
4448 +}
4449 +
4450 +static void set_rq_offline(struct rq *rq)
4451 +{
4452 + if (rq->online) {
4453 + cpumask_clear_cpu(rq->cpu, rq->rd->online);
4454 + rq->online = 0;
4455 + }
4456 +}
4457 +
4458 +#ifdef CONFIG_HOTPLUG_CPU
4459 +/*
4460 + * This cpu is going down, so walk over the tasklist and find tasks that can
4461 + * only run on this cpu and remove their affinity. Store their value in
4462 + * unplugged_mask so it can be restored once their correct cpu is online. No
4463 + * need to do anything special since they'll just move on next reschedule if
4464 + * they're running.
4465 + */
4466 +static void remove_cpu(unsigned long cpu)
4467 +{
4468 + struct task_struct *p, *t;
4469 +
4470 + read_lock(&tasklist_lock);
4471 +
4472 + do_each_thread(t, p) {
4473 + cpumask_t cpus_remaining;
4474 +
4475 + cpus_and(cpus_remaining, p->cpus_allowed, cpu_online_map);
4476 + cpu_clear(cpu, cpus_remaining);
4477 + if (cpus_empty(cpus_remaining)) {
4478 + p->unplugged_mask = p->cpus_allowed;
4479 + p->cpus_allowed = cpu_possible_map;
4480 + }
4481 + } while_each_thread(t, p);
4482 +
4483 + read_unlock(&tasklist_lock);
4484 +}
4485 +
4486 +/*
4487 + * This cpu is coming up so add it to the cpus_allowed.
4488 + */
4489 +static void add_cpu(unsigned long cpu)
4490 +{
4491 + struct task_struct *p, *t;
4492 +
4493 + read_lock(&tasklist_lock);
4494 +
4495 + do_each_thread(t, p) {
4496 + /* Have we taken all the cpus from the unplugged_mask back */
4497 + if (cpus_empty(p->unplugged_mask))
4498 + continue;
4499 +
4500 + /* Was this cpu in the unplugged_mask mask */
4501 + if (cpu_isset(cpu, p->unplugged_mask)) {
4502 + cpu_set(cpu, p->cpus_allowed);
4503 + if (cpus_subset(p->unplugged_mask, p->cpus_allowed)) {
4504 + /*
4505 + * Have we set more than the unplugged_mask?
4506 + * If so, that means we have remnants set from
4507 + * the unplug/plug cycle and need to remove
4508 + * them. Then clear the unplugged_mask as we've
4509 + * set all the cpus back.
4510 + */
4511 + p->cpus_allowed = p->unplugged_mask;
4512 + cpus_clear(p->unplugged_mask);
4513 + }
4514 + }
4515 + } while_each_thread(t, p);
4516 +
4517 + read_unlock(&tasklist_lock);
4518 +}
4519 +#else
4520 +static void add_cpu(unsigned long cpu)
4521 +{
4522 +}
4523 +#endif
4524 +
4525 +/*
4526 + * migration_call - callback that gets triggered when a CPU is added.
4527 + */
4528 +static int __cpuinit
4529 +migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
4530 +{
4531 + int cpu = (long)hcpu;
4532 + unsigned long flags;
4533 + struct rq *rq;
4534 +
4535 + switch (action) {
4536 +
4537 + case CPU_UP_PREPARE:
4538 + case CPU_UP_PREPARE_FROZEN:
4539 + break;
4540 +
4541 + case CPU_ONLINE:
4542 + case CPU_ONLINE_FROZEN:
4543 + /* Update our root-domain */
4544 + rq = cpu_rq(cpu);
4545 + grq_lock_irqsave(&flags);
4546 + if (rq->rd) {
4547 + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
4548 +
4549 + set_rq_online(rq);
4550 + }
4551 + add_cpu(cpu);
4552 + grq_unlock_irqrestore(&flags);
4553 + break;
4554 +
4555 +#ifdef CONFIG_HOTPLUG_CPU
4556 + case CPU_UP_CANCELED:
4557 + case CPU_UP_CANCELED_FROZEN:
4558 + break;
4559 +
4560 + case CPU_DEAD:
4561 + case CPU_DEAD_FROZEN:
4562 + cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
4563 + rq = cpu_rq(cpu);
4564 + /* Idle task back to normal (off runqueue, low prio) */
4565 + grq_lock_irq();
4566 + remove_cpu(cpu);
4567 + deactivate_task(rq->idle);
4568 + rq->idle->static_prio = MAX_PRIO;
4569 + __setscheduler(rq->idle, SCHED_NORMAL, 0);
4570 + rq->idle->prio = PRIO_LIMIT;
4571 + update_rq_clock(rq);
4572 + grq_unlock_irq();
4573 + cpuset_unlock();
4574 + break;
4575 +
4576 + case CPU_DYING:
4577 + case CPU_DYING_FROZEN:
4578 + rq = cpu_rq(cpu);
4579 + grq_lock_irqsave(&flags);
4580 + if (rq->rd) {
4581 + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
4582 + set_rq_offline(rq);
4583 + }
4584 + grq_unlock_irqrestore(&flags);
4585 + break;
4586 +#endif
4587 + }
4588 + return NOTIFY_OK;
4589 +}
4590 +
4591 +/*
4592 + * Register at high priority so that task migration (migrate_all_tasks)
4593 + * happens before everything else. This has to be lower priority than
4594 + * the notifier in the perf_counter subsystem, though.
4595 + */
4596 +static struct notifier_block __cpuinitdata migration_notifier = {
4597 + .notifier_call = migration_call,
4598 + .priority = 10
4599 +};
4600 +
4601 +int __init migration_init(void)
4602 +{
4603 + void *cpu = (void *)(long)smp_processor_id();
4604 + int err;
4605 +
4606 + /* Start one for the boot CPU: */
4607 + err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
4608 + BUG_ON(err == NOTIFY_BAD);
4609 + migration_call(&migration_notifier, CPU_ONLINE, cpu);
4610 + register_cpu_notifier(&migration_notifier);
4611 +
4612 + return 0;
4613 +}
4614 +early_initcall(migration_init);
4615 +#endif
4616 +
4617 +/*
4618 + * sched_domains_mutex serializes calls to arch_init_sched_domains,
4619 + * detach_destroy_domains and partition_sched_domains.
4620 + */
4621 +static DEFINE_MUTEX(sched_domains_mutex);
4622 +
4623 +#ifdef CONFIG_SMP
4624 +
4625 +#ifdef CONFIG_SCHED_DEBUG
4626 +
4627 +static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
4628 + struct cpumask *groupmask)
4629 +{
4630 + struct sched_group *group = sd->groups;
4631 + char str[256];
4632 +
4633 + cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
4634 + cpumask_clear(groupmask);
4635 +
4636 + printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
4637 +
4638 + if (!(sd->flags & SD_LOAD_BALANCE)) {
4639 + printk("does not load-balance\n");
4640 + if (sd->parent)
4641 + printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
4642 + " has parent");
4643 + return -1;
4644 + }
4645 +
4646 + printk(KERN_CONT "span %s level %s\n", str, sd->name);
4647 +
4648 + if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
4649 + printk(KERN_ERR "ERROR: domain->span does not contain "
4650 + "CPU%d\n", cpu);
4651 + }
4652 + if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
4653 + printk(KERN_ERR "ERROR: domain->groups does not contain"
4654 + " CPU%d\n", cpu);
4655 + }
4656 +
4657 + printk(KERN_DEBUG "%*s groups:", level + 1, "");
4658 + do {
4659 + if (!group) {
4660 + printk("\n");
4661 + printk(KERN_ERR "ERROR: group is NULL\n");
4662 + break;
4663 + }
4664 +
4665 + if (!group->__cpu_power) {
4666 + printk(KERN_CONT "\n");
4667 + printk(KERN_ERR "ERROR: domain->cpu_power not "
4668 + "set\n");
4669 + break;
4670 + }
4671 +
4672 + if (!cpumask_weight(sched_group_cpus(group))) {
4673 + printk(KERN_CONT "\n");
4674 + printk(KERN_ERR "ERROR: empty group\n");
4675 + break;
4676 + }
4677 +
4678 + if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
4679 + printk(KERN_CONT "\n");
4680 + printk(KERN_ERR "ERROR: repeated CPUs\n");
4681 + break;
4682 + }
4683 +
4684 + cpumask_or(groupmask, groupmask, sched_group_cpus(group));
4685 +
4686 + cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
4687 +
4688 + printk(KERN_CONT " %s", str);
4689 + if (group->__cpu_power != SCHED_LOAD_SCALE) {
4690 + printk(KERN_CONT " (__cpu_power = %d)",
4691 + group->__cpu_power);
4692 + }
4693 +
4694 + group = group->next;
4695 + } while (group != sd->groups);
4696 + printk(KERN_CONT "\n");
4697 +
4698 + if (!cpumask_equal(sched_domain_span(sd), groupmask))
4699 + printk(KERN_ERR "ERROR: groups don't span domain->span\n");
4700 +
4701 + if (sd->parent &&
4702 + !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
4703 + printk(KERN_ERR "ERROR: parent span is not a superset "
4704 + "of domain->span\n");
4705 + return 0;
4706 +}
4707 +
4708 +static void sched_domain_debug(struct sched_domain *sd, int cpu)
4709 +{
4710 + cpumask_var_t groupmask;
4711 + int level = 0;
4712 +
4713 + if (!sd) {
4714 + printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
4715 + return;
4716 + }
4717 +
4718 + printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
4719 +
4720 + if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
4721 + printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
4722 + return;
4723 + }
4724 +
4725 + for (;;) {
4726 + if (sched_domain_debug_one(sd, cpu, level, groupmask))
4727 + break;
4728 + level++;
4729 + sd = sd->parent;
4730 + if (!sd)
4731 + break;
4732 + }
4733 + free_cpumask_var(groupmask);
4734 +}
4735 +#else /* !CONFIG_SCHED_DEBUG */
4736 +# define sched_domain_debug(sd, cpu) do { } while (0)
4737 +#endif /* CONFIG_SCHED_DEBUG */
4738 +
4739 +static int sd_degenerate(struct sched_domain *sd)
4740 +{
4741 + if (cpumask_weight(sched_domain_span(sd)) == 1)
4742 + return 1;
4743 +
4744 + /* Following flags need at least 2 groups */
4745 + if (sd->flags & (SD_LOAD_BALANCE |
4746 + SD_BALANCE_NEWIDLE |
4747 + SD_BALANCE_FORK |
4748 + SD_BALANCE_EXEC |
4749 + SD_SHARE_CPUPOWER |
4750 + SD_SHARE_PKG_RESOURCES)) {
4751 + if (sd->groups != sd->groups->next)
4752 + return 0;
4753 + }
4754 +
4755 + /* Following flags don't use groups */
4756 + if (sd->flags & (SD_WAKE_IDLE |
4757 + SD_WAKE_AFFINE |
4758 + SD_WAKE_BALANCE))
4759 + return 0;
4760 +
4761 + return 1;
4762 +}
4763 +
4764 +static int
4765 +sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
4766 +{
4767 + unsigned long cflags = sd->flags, pflags = parent->flags;
4768 +
4769 + if (sd_degenerate(parent))
4770 + return 1;
4771 +
4772 + if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
4773 + return 0;
4774 +
4775 + /* Does parent contain flags not in child? */
4776 + /* WAKE_BALANCE is a subset of WAKE_AFFINE */
4777 + if (cflags & SD_WAKE_AFFINE)
4778 + pflags &= ~SD_WAKE_BALANCE;
4779 + /* Flags needing groups don't count if only 1 group in parent */
4780 + if (parent->groups == parent->groups->next) {
4781 + pflags &= ~(SD_LOAD_BALANCE |
4782 + SD_BALANCE_NEWIDLE |
4783 + SD_BALANCE_FORK |
4784 + SD_BALANCE_EXEC |
4785 + SD_SHARE_CPUPOWER |
4786 + SD_SHARE_PKG_RESOURCES);
4787 + if (nr_node_ids == 1)
4788 + pflags &= ~SD_SERIALIZE;
4789 + }
4790 + if (~cflags & pflags)
4791 + return 0;
4792 +
4793 + return 1;
4794 +}
4795 +
4796 +static void free_rootdomain(struct root_domain *rd)
4797 +{
4798 + free_cpumask_var(rd->rto_mask);
4799 + free_cpumask_var(rd->online);
4800 + free_cpumask_var(rd->span);
4801 + kfree(rd);
4802 +}
4803 +
4804 +static void rq_attach_root(struct rq *rq, struct root_domain *rd)
4805 +{
4806 + struct root_domain *old_rd = NULL;
4807 + unsigned long flags;
4808 +
4809 + grq_lock_irqsave(&flags);
4810 +
4811 + if (rq->rd) {
4812 + old_rd = rq->rd;
4813 +
4814 + if (cpumask_test_cpu(rq->cpu, old_rd->online))
4815 + set_rq_offline(rq);
4816 +
4817 + cpumask_clear_cpu(rq->cpu, old_rd->span);
4818 +
4819 + /*
4820 + * If we dont want to free the old_rt yet then
4821 + * set old_rd to NULL to skip the freeing later
4822 + * in this function:
4823 + */
4824 + if (!atomic_dec_and_test(&old_rd->refcount))
4825 + old_rd = NULL;
4826 + }
4827 +
4828 + atomic_inc(&rd->refcount);
4829 + rq->rd = rd;
4830 +
4831 + cpumask_set_cpu(rq->cpu, rd->span);
4832 + if (cpumask_test_cpu(rq->cpu, cpu_online_mask))
4833 + set_rq_online(rq);
4834 +
4835 + grq_unlock_irqrestore(&flags);
4836 +
4837 + if (old_rd)
4838 + free_rootdomain(old_rd);
4839 +}
4840 +
4841 +static int init_rootdomain(struct root_domain *rd, bool bootmem)
4842 +{
4843 + gfp_t gfp = GFP_KERNEL;
4844 +
4845 + memset(rd, 0, sizeof(*rd));
4846 +
4847 + if (bootmem)
4848 + gfp = GFP_NOWAIT;
4849 +
4850 + if (!alloc_cpumask_var(&rd->span, gfp))
4851 + goto out;
4852 + if (!alloc_cpumask_var(&rd->online, gfp))
4853 + goto free_span;
4854 + if (!alloc_cpumask_var(&rd->rto_mask, gfp))
4855 + goto free_online;
4856 +
4857 + return 0;
4858 +
4859 +free_online:
4860 + free_cpumask_var(rd->online);
4861 +free_span:
4862 + free_cpumask_var(rd->span);
4863 +out:
4864 + return -ENOMEM;
4865 +}
4866 +
4867 +static void init_defrootdomain(void)
4868 +{
4869 + init_rootdomain(&def_root_domain, true);
4870 +
4871 + atomic_set(&def_root_domain.refcount, 1);
4872 +}
4873 +
4874 +static struct root_domain *alloc_rootdomain(void)
4875 +{
4876 + struct root_domain *rd;
4877 +
4878 + rd = kmalloc(sizeof(*rd), GFP_KERNEL);
4879 + if (!rd)
4880 + return NULL;
4881 +
4882 + if (init_rootdomain(rd, false) != 0) {
4883 + kfree(rd);
4884 + return NULL;
4885 + }
4886 +
4887 + return rd;
4888 +}
4889 +
4890 +/*
4891 + * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
4892 + * hold the hotplug lock.
4893 + */
4894 +static void
4895 +cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
4896 +{
4897 + struct rq *rq = cpu_rq(cpu);
4898 + struct sched_domain *tmp;
4899 +
4900 + /* Remove the sched domains which do not contribute to scheduling. */
4901 + for (tmp = sd; tmp; ) {
4902 + struct sched_domain *parent = tmp->parent;
4903 + if (!parent)
4904 + break;
4905 +
4906 + if (sd_parent_degenerate(tmp, parent)) {
4907 + tmp->parent = parent->parent;
4908 + if (parent->parent)
4909 + parent->parent->child = tmp;
4910 + } else
4911 + tmp = tmp->parent;
4912 + }
4913 +
4914 + if (sd && sd_degenerate(sd)) {
4915 + sd = sd->parent;
4916 + if (sd)
4917 + sd->child = NULL;
4918 + }
4919 +
4920 + sched_domain_debug(sd, cpu);
4921 +
4922 + rq_attach_root(rq, rd);
4923 + rcu_assign_pointer(rq->sd, sd);
4924 +}
4925 +
4926 +/* cpus with isolated domains */
4927 +static cpumask_var_t cpu_isolated_map;
4928 +
4929 +/* Setup the mask of cpus configured for isolated domains */
4930 +static int __init isolated_cpu_setup(char *str)
4931 +{
4932 + cpulist_parse(str, cpu_isolated_map);
4933 + return 1;
4934 +}
4935 +
4936 +__setup("isolcpus=", isolated_cpu_setup);
4937 +
4938 +/*
4939 + * init_sched_build_groups takes the cpumask we wish to span, and a pointer
4940 + * to a function which identifies what group(along with sched group) a CPU
4941 + * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
4942 + * (due to the fact that we keep track of groups covered with a struct cpumask).
4943 + *
4944 + * init_sched_build_groups will build a circular linked list of the groups
4945 + * covered by the given span, and will set each group's ->cpumask correctly,
4946 + * and ->cpu_power to 0.
4947 + */
4948 +static void
4949 +init_sched_build_groups(const struct cpumask *span,
4950 + const struct cpumask *cpu_map,
4951 + int (*group_fn)(int cpu, const struct cpumask *cpu_map,
4952 + struct sched_group **sg,
4953 + struct cpumask *tmpmask),
4954 + struct cpumask *covered, struct cpumask *tmpmask)
4955 +{
4956 + struct sched_group *first = NULL, *last = NULL;
4957 + int i;
4958 +
4959 + cpumask_clear(covered);
4960 +
4961 + for_each_cpu(i, span) {
4962 + struct sched_group *sg;
4963 + int group = group_fn(i, cpu_map, &sg, tmpmask);
4964 + int j;
4965 +
4966 + if (cpumask_test_cpu(i, covered))
4967 + continue;
4968 +
4969 + cpumask_clear(sched_group_cpus(sg));
4970 + sg->__cpu_power = 0;
4971 +
4972 + for_each_cpu(j, span) {
4973 + if (group_fn(j, cpu_map, NULL, tmpmask) != group)
4974 + continue;
4975 +
4976 + cpumask_set_cpu(j, covered);
4977 + cpumask_set_cpu(j, sched_group_cpus(sg));
4978 + }
4979 + if (!first)
4980 + first = sg;
4981 + if (last)
4982 + last->next = sg;
4983 + last = sg;
4984 + }
4985 + last->next = first;
4986 +}
4987 +
4988 +#define SD_NODES_PER_DOMAIN 16
4989 +
4990 +#ifdef CONFIG_NUMA
4991 +
4992 +/**
4993 + * find_next_best_node - find the next node to include in a sched_domain
4994 + * @node: node whose sched_domain we're building
4995 + * @used_nodes: nodes already in the sched_domain
4996 + *
4997 + * Find the next node to include in a given scheduling domain. Simply
4998 + * finds the closest node not already in the @used_nodes map.
4999 + *
5000 + * Should use nodemask_t.
5001 + */
5002 +static int find_next_best_node(int node, nodemask_t *used_nodes)
5003 +{
5004 + int i, n, val, min_val, best_node = 0;
5005 +
5006 + min_val = INT_MAX;
5007 +
5008 + for (i = 0; i < nr_node_ids; i++) {
5009 + /* Start at @node */
5010 + n = (node + i) % nr_node_ids;
5011 +
5012 + if (!nr_cpus_node(n))
5013 + continue;
5014 +
5015 + /* Skip already used nodes */
5016 + if (node_isset(n, *used_nodes))
5017 + continue;
5018 +
5019 + /* Simple min distance search */
5020 + val = node_distance(node, n);
5021 +
5022 + if (val < min_val) {
5023 + min_val = val;
5024 + best_node = n;
5025 + }
5026 + }
5027 +
5028 + node_set(best_node, *used_nodes);
5029 + return best_node;
5030 +}
5031 +
5032 +/**
5033 + * sched_domain_node_span - get a cpumask for a node's sched_domain
5034 + * @node: node whose cpumask we're constructing
5035 + * @span: resulting cpumask
5036 + *
5037 + * Given a node, construct a good cpumask for its sched_domain to span. It
5038 + * should be one that prevents unnecessary balancing, but also spreads tasks
5039 + * out optimally.
5040 + */
5041 +static void sched_domain_node_span(int node, struct cpumask *span)
5042 +{
5043 + nodemask_t used_nodes;
5044 + int i;
5045 +
5046 + cpumask_clear(span);
5047 + nodes_clear(used_nodes);
5048 +
5049 + cpumask_or(span, span, cpumask_of_node(node));
5050 + node_set(node, used_nodes);
5051 +
5052 + for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
5053 + int next_node = find_next_best_node(node, &used_nodes);
5054 +
5055 + cpumask_or(span, span, cpumask_of_node(next_node));
5056 + }
5057 +}
5058 +#endif /* CONFIG_NUMA */
5059 +
5060 +int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
5061 +
5062 +/*
5063 + * The cpus mask in sched_group and sched_domain hangs off the end.
5064 + *
5065 + * ( See the the comments in include/linux/sched.h:struct sched_group
5066 + * and struct sched_domain. )
5067 + */
5068 +struct static_sched_group {
5069 + struct sched_group sg;
5070 + DECLARE_BITMAP(cpus, CONFIG_NR_CPUS);
5071 +};
5072 +
5073 +struct static_sched_domain {
5074 + struct sched_domain sd;
5075 + DECLARE_BITMAP(span, CONFIG_NR_CPUS);
5076 +};
5077 +
5078 +/*
5079 + * SMT sched-domains:
5080 + */
5081 +#ifdef CONFIG_SCHED_SMT
5082 +static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
5083 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
5084 +
5085 +static int
5086 +cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
5087 + struct sched_group **sg, struct cpumask *unused)
5088 +{
5089 + if (sg)
5090 + *sg = &per_cpu(sched_group_cpus, cpu).sg;
5091 + return cpu;
5092 +}
5093 +#endif /* CONFIG_SCHED_SMT */
5094 +
5095 +/*
5096 + * multi-core sched-domains:
5097 + */
5098 +#ifdef CONFIG_SCHED_MC
5099 +static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
5100 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
5101 +#endif /* CONFIG_SCHED_MC */
5102 +
5103 +#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
5104 +static int
5105 +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
5106 + struct sched_group **sg, struct cpumask *mask)
5107 +{
5108 + int group;
5109 +
5110 + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
5111 + group = cpumask_first(mask);
5112 + if (sg)
5113 + *sg = &per_cpu(sched_group_core, group).sg;
5114 + return group;
5115 +}
5116 +#elif defined(CONFIG_SCHED_MC)
5117 +static int
5118 +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
5119 + struct sched_group **sg, struct cpumask *unused)
5120 +{
5121 + if (sg)
5122 + *sg = &per_cpu(sched_group_core, cpu).sg;
5123 + return cpu;
5124 +}
5125 +#endif
5126 +
5127 +static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
5128 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
5129 +
5130 +static int
5131 +cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
5132 + struct sched_group **sg, struct cpumask *mask)
5133 +{
5134 + int group;
5135 +#ifdef CONFIG_SCHED_MC
5136 + cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
5137 + group = cpumask_first(mask);
5138 +#elif defined(CONFIG_SCHED_SMT)
5139 + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
5140 + group = cpumask_first(mask);
5141 +#else
5142 + group = cpu;
5143 +#endif
5144 + if (sg)
5145 + *sg = &per_cpu(sched_group_phys, group).sg;
5146 + return group;
5147 +}
5148 +
5149 +/**
5150 + * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
5151 + * @group: The group whose first cpu is to be returned.
5152 + */
5153 +static inline unsigned int group_first_cpu(struct sched_group *group)
5154 +{
5155 + return cpumask_first(sched_group_cpus(group));
5156 +}
5157 +
5158 +#ifdef CONFIG_NUMA
5159 +/*
5160 + * The init_sched_build_groups can't handle what we want to do with node
5161 + * groups, so roll our own. Now each node has its own list of groups which
5162 + * gets dynamically allocated.
5163 + */
5164 +static DEFINE_PER_CPU(struct static_sched_domain, node_domains);
5165 +static struct sched_group ***sched_group_nodes_bycpu;
5166 +
5167 +static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains);
5168 +static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes);
5169 +
5170 +static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map,
5171 + struct sched_group **sg,
5172 + struct cpumask *nodemask)
5173 +{
5174 + int group;
5175 +
5176 + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);
5177 + group = cpumask_first(nodemask);
5178 +
5179 + if (sg)
5180 + *sg = &per_cpu(sched_group_allnodes, group).sg;
5181 + return group;
5182 +}
5183 +
5184 +static void init_numa_sched_groups_power(struct sched_group *group_head)
5185 +{
5186 + struct sched_group *sg = group_head;
5187 + int j;
5188 +
5189 + if (!sg)
5190 + return;
5191 + do {
5192 + for_each_cpu(j, sched_group_cpus(sg)) {
5193 + struct sched_domain *sd;
5194 +
5195 + sd = &per_cpu(phys_domains, j).sd;
5196 + if (j != group_first_cpu(sd->groups)) {
5197 + /*
5198 + * Only add "power" once for each
5199 + * physical package.
5200 + */
5201 + continue;
5202 + }
5203 +
5204 + sg_inc_cpu_power(sg, sd->groups->__cpu_power);
5205 + }
5206 + sg = sg->next;
5207 + } while (sg != group_head);
5208 +}
5209 +#endif /* CONFIG_NUMA */
5210 +
5211 +#ifdef CONFIG_NUMA
5212 +/* Free memory allocated for various sched_group structures */
5213 +static void free_sched_groups(const struct cpumask *cpu_map,
5214 + struct cpumask *nodemask)
5215 +{
5216 + int cpu, i;
5217 +
5218 + for_each_cpu(cpu, cpu_map) {
5219 + struct sched_group **sched_group_nodes
5220 + = sched_group_nodes_bycpu[cpu];
5221 +
5222 + if (!sched_group_nodes)
5223 + continue;
5224 +
5225 + for (i = 0; i < nr_node_ids; i++) {
5226 + struct sched_group *oldsg, *sg = sched_group_nodes[i];
5227 +
5228 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5229 + if (cpumask_empty(nodemask))
5230 + continue;
5231 +
5232 + if (sg == NULL)
5233 + continue;
5234 + sg = sg->next;
5235 +next_sg:
5236 + oldsg = sg;
5237 + sg = sg->next;
5238 + kfree(oldsg);
5239 + if (oldsg != sched_group_nodes[i])
5240 + goto next_sg;
5241 + }
5242 + kfree(sched_group_nodes);
5243 + sched_group_nodes_bycpu[cpu] = NULL;
5244 + }
5245 +}
5246 +#else /* !CONFIG_NUMA */
5247 +static void free_sched_groups(const struct cpumask *cpu_map,
5248 + struct cpumask *nodemask)
5249 +{
5250 +}
5251 +#endif /* CONFIG_NUMA */
5252 +
5253 +/*
5254 + * Initialize sched groups cpu_power.
5255 + *
5256 + * cpu_power indicates the capacity of sched group, which is used while
5257 + * distributing the load between different sched groups in a sched domain.
5258 + * Typically cpu_power for all the groups in a sched domain will be same unless
5259 + * there are asymmetries in the topology. If there are asymmetries, group
5260 + * having more cpu_power will pickup more load compared to the group having
5261 + * less cpu_power.
5262 + *
5263 + * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
5264 + * the maximum number of tasks a group can handle in the presence of other idle
5265 + * or lightly loaded groups in the same sched domain.
5266 + */
5267 +static void init_sched_groups_power(int cpu, struct sched_domain *sd)
5268 +{
5269 + struct sched_domain *child;
5270 + struct sched_group *group;
5271 +
5272 + WARN_ON(!sd || !sd->groups);
5273 +
5274 + if (cpu != group_first_cpu(sd->groups))
5275 + return;
5276 +
5277 + child = sd->child;
5278 +
5279 + sd->groups->__cpu_power = 0;
5280 +
5281 + /*
5282 + * For perf policy, if the groups in child domain share resources
5283 + * (for example cores sharing some portions of the cache hierarchy
5284 + * or SMT), then set this domain groups cpu_power such that each group
5285 + * can handle only one task, when there are other idle groups in the
5286 + * same sched domain.
5287 + */
5288 + if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
5289 + (child->flags &
5290 + (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
5291 + sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
5292 + return;
5293 + }
5294 +
5295 + /*
5296 + * add cpu_power of each child group to this groups cpu_power
5297 + */
5298 + group = child->groups;
5299 + do {
5300 + sg_inc_cpu_power(sd->groups, group->__cpu_power);
5301 + group = group->next;
5302 + } while (group != child->groups);
5303 +}
5304 +
5305 +/*
5306 + * Initializers for schedule domains
5307 + * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
5308 + */
5309 +
5310 +#ifdef CONFIG_SCHED_DEBUG
5311 +# define SD_INIT_NAME(sd, type) sd->name = #type
5312 +#else
5313 +# define SD_INIT_NAME(sd, type) do { } while (0)
5314 +#endif
5315 +
5316 +#define SD_INIT(sd, type) sd_init_##type(sd)
5317 +
5318 +#define SD_INIT_FUNC(type) \
5319 +static noinline void sd_init_##type(struct sched_domain *sd) \
5320 +{ \
5321 + memset(sd, 0, sizeof(*sd)); \
5322 + *sd = SD_##type##_INIT; \
5323 + sd->level = SD_LV_##type; \
5324 + SD_INIT_NAME(sd, type); \
5325 +}
5326 +
5327 +SD_INIT_FUNC(CPU)
5328 +#ifdef CONFIG_NUMA
5329 + SD_INIT_FUNC(ALLNODES)
5330 + SD_INIT_FUNC(NODE)
5331 +#endif
5332 +#ifdef CONFIG_SCHED_SMT
5333 + SD_INIT_FUNC(SIBLING)
5334 +#endif
5335 +#ifdef CONFIG_SCHED_MC
5336 + SD_INIT_FUNC(MC)
5337 +#endif
5338 +
5339 +static int default_relax_domain_level = -1;
5340 +
5341 +static int __init setup_relax_domain_level(char *str)
5342 +{
5343 + unsigned long val;
5344 +
5345 + val = simple_strtoul(str, NULL, 0);
5346 + if (val < SD_LV_MAX)
5347 + default_relax_domain_level = val;
5348 +
5349 + return 1;
5350 +}
5351 +__setup("relax_domain_level=", setup_relax_domain_level);
5352 +
5353 +static void set_domain_attribute(struct sched_domain *sd,
5354 + struct sched_domain_attr *attr)
5355 +{
5356 + int request;
5357 +
5358 + if (!attr || attr->relax_domain_level < 0) {
5359 + if (default_relax_domain_level < 0)
5360 + return;
5361 + else
5362 + request = default_relax_domain_level;
5363 + } else
5364 + request = attr->relax_domain_level;
5365 + if (request < sd->level) {
5366 + /* turn off idle balance on this domain */
5367 + sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
5368 + } else {
5369 + /* turn on idle balance on this domain */
5370 + sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
5371 + }
5372 +}
5373 +
5374 +/*
5375 + * Build sched domains for a given set of cpus and attach the sched domains
5376 + * to the individual cpus
5377 + */
5378 +static int __build_sched_domains(const struct cpumask *cpu_map,
5379 + struct sched_domain_attr *attr)
5380 +{
5381 + int i, err = -ENOMEM;
5382 + struct root_domain *rd;
5383 + cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered,
5384 + tmpmask;
5385 +#ifdef CONFIG_NUMA
5386 + cpumask_var_t domainspan, covered, notcovered;
5387 + struct sched_group **sched_group_nodes = NULL;
5388 + int sd_allnodes = 0;
5389 +
5390 + if (!alloc_cpumask_var(&domainspan, GFP_KERNEL))
5391 + goto out;
5392 + if (!alloc_cpumask_var(&covered, GFP_KERNEL))
5393 + goto free_domainspan;
5394 + if (!alloc_cpumask_var(&notcovered, GFP_KERNEL))
5395 + goto free_covered;
5396 +#endif
5397 +
5398 + if (!alloc_cpumask_var(&nodemask, GFP_KERNEL))
5399 + goto free_notcovered;
5400 + if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL))
5401 + goto free_nodemask;
5402 + if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL))
5403 + goto free_this_sibling_map;
5404 + if (!alloc_cpumask_var(&send_covered, GFP_KERNEL))
5405 + goto free_this_core_map;
5406 + if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
5407 + goto free_send_covered;
5408 +
5409 +#ifdef CONFIG_NUMA
5410 + /*
5411 + * Allocate the per-node list of sched groups
5412 + */
5413 + sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
5414 + GFP_KERNEL);
5415 + if (!sched_group_nodes) {
5416 + printk(KERN_WARNING "Can not alloc sched group node list\n");
5417 + goto free_tmpmask;
5418 + }
5419 +#endif
5420 +
5421 + rd = alloc_rootdomain();
5422 + if (!rd) {
5423 + printk(KERN_WARNING "Cannot alloc root domain\n");
5424 + goto free_sched_groups;
5425 + }
5426 +
5427 +#ifdef CONFIG_NUMA
5428 + sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes;
5429 +#endif
5430 +
5431 + /*
5432 + * Set up domains for cpus specified by the cpu_map.
5433 + */
5434 + for_each_cpu(i, cpu_map) {
5435 + struct sched_domain *sd = NULL, *p;
5436 +
5437 + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);
5438 +
5439 +#ifdef CONFIG_NUMA
5440 + if (cpumask_weight(cpu_map) >
5441 + SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) {
5442 + sd = &per_cpu(allnodes_domains, i).sd;
5443 + SD_INIT(sd, ALLNODES);
5444 + set_domain_attribute(sd, attr);
5445 + cpumask_copy(sched_domain_span(sd), cpu_map);
5446 + cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
5447 + p = sd;
5448 + sd_allnodes = 1;
5449 + } else
5450 + p = NULL;
5451 +
5452 + sd = &per_cpu(node_domains, i).sd;
5453 + SD_INIT(sd, NODE);
5454 + set_domain_attribute(sd, attr);
5455 + sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
5456 + sd->parent = p;
5457 + if (p)
5458 + p->child = sd;
5459 + cpumask_and(sched_domain_span(sd),
5460 + sched_domain_span(sd), cpu_map);
5461 +#endif
5462 +
5463 + p = sd;
5464 + sd = &per_cpu(phys_domains, i).sd;
5465 + SD_INIT(sd, CPU);
5466 + set_domain_attribute(sd, attr);
5467 + cpumask_copy(sched_domain_span(sd), nodemask);
5468 + sd->parent = p;
5469 + if (p)
5470 + p->child = sd;
5471 + cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
5472 +
5473 +#ifdef CONFIG_SCHED_MC
5474 + p = sd;
5475 + sd = &per_cpu(core_domains, i).sd;
5476 + SD_INIT(sd, MC);
5477 + set_domain_attribute(sd, attr);
5478 + cpumask_and(sched_domain_span(sd), cpu_map,
5479 + cpu_coregroup_mask(i));
5480 + sd->parent = p;
5481 + p->child = sd;
5482 + cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
5483 +#endif
5484 +
5485 +#ifdef CONFIG_SCHED_SMT
5486 + p = sd;
5487 + sd = &per_cpu(cpu_domains, i).sd;
5488 + SD_INIT(sd, SIBLING);
5489 + set_domain_attribute(sd, attr);
5490 + cpumask_and(sched_domain_span(sd),
5491 + topology_thread_cpumask(i), cpu_map);
5492 + sd->parent = p;
5493 + p->child = sd;
5494 + cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
5495 +#endif
5496 + }
5497 +
5498 +#ifdef CONFIG_SCHED_SMT
5499 + /* Set up CPU (sibling) groups */
5500 + for_each_cpu(i, cpu_map) {
5501 + cpumask_and(this_sibling_map,
5502 + topology_thread_cpumask(i), cpu_map);
5503 + if (i != cpumask_first(this_sibling_map))
5504 + continue;
5505 +
5506 + init_sched_build_groups(this_sibling_map, cpu_map,
5507 + &cpu_to_cpu_group,
5508 + send_covered, tmpmask);
5509 + }
5510 +#endif
5511 +
5512 +#ifdef CONFIG_SCHED_MC
5513 + /* Set up multi-core groups */
5514 + for_each_cpu(i, cpu_map) {
5515 + cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);
5516 + if (i != cpumask_first(this_core_map))
5517 + continue;
5518 +
5519 + init_sched_build_groups(this_core_map, cpu_map,
5520 + &cpu_to_core_group,
5521 + send_covered, tmpmask);
5522 + }
5523 +#endif
5524 +
5525 + /* Set up physical groups */
5526 + for (i = 0; i < nr_node_ids; i++) {
5527 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5528 + if (cpumask_empty(nodemask))
5529 + continue;
5530 +
5531 + init_sched_build_groups(nodemask, cpu_map,
5532 + &cpu_to_phys_group,
5533 + send_covered, tmpmask);
5534 + }
5535 +
5536 +#ifdef CONFIG_NUMA
5537 + /* Set up node groups */
5538 + if (sd_allnodes) {
5539 + init_sched_build_groups(cpu_map, cpu_map,
5540 + &cpu_to_allnodes_group,
5541 + send_covered, tmpmask);
5542 + }
5543 +
5544 + for (i = 0; i < nr_node_ids; i++) {
5545 + /* Set up node groups */
5546 + struct sched_group *sg, *prev;
5547 + int j;
5548 +
5549 + cpumask_clear(covered);
5550 + cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
5551 + if (cpumask_empty(nodemask)) {
5552 + sched_group_nodes[i] = NULL;
5553 + continue;
5554 + }
5555 +
5556 + sched_domain_node_span(i, domainspan);
5557 + cpumask_and(domainspan, domainspan, cpu_map);
5558 +
5559 + sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
5560 + GFP_KERNEL, i);
5561 + if (!sg) {
5562 + printk(KERN_WARNING "Can not alloc domain group for "
5563 + "node %d\n", i);
5564 + goto error;
5565 + }
5566 + sched_group_nodes[i] = sg;
5567 + for_each_cpu(j, nodemask) {
5568 + struct sched_domain *sd;
5569 +
5570 + sd = &per_cpu(node_domains, j).sd;
5571 + sd->groups = sg;
5572 + }
5573 + sg->__cpu_power = 0;
5574 + cpumask_copy(sched_group_cpus(sg), nodemask);
5575 + sg->next = sg;
5576 + cpumask_or(covered, covered, nodemask);
5577 + prev = sg;
5578 +
5579 + for (j = 0; j < nr_node_ids; j++) {
5580 + int n = (i + j) % nr_node_ids;
5581 +
5582 + cpumask_complement(notcovered, covered);
5583 + cpumask_and(tmpmask, notcovered, cpu_map);
5584 + cpumask_and(tmpmask, tmpmask, domainspan);
5585 + if (cpumask_empty(tmpmask))
5586 + break;
5587 +
5588 + cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));
5589 + if (cpumask_empty(tmpmask))
5590 + continue;
5591 +
5592 + sg = kmalloc_node(sizeof(struct sched_group) +
5593 + cpumask_size(),
5594 + GFP_KERNEL, i);
5595 + if (!sg) {
5596 + printk(KERN_WARNING
5597 + "Can not alloc domain group for node %d\n", j);
5598 + goto error;
5599 + }
5600 + sg->__cpu_power = 0;
5601 + cpumask_copy(sched_group_cpus(sg), tmpmask);
5602 + sg->next = prev->next;
5603 + cpumask_or(covered, covered, tmpmask);
5604 + prev->next = sg;
5605 + prev = sg;
5606 + }
5607 + }
5608 +#endif
5609 +
5610 + /* Calculate CPU power for physical packages and nodes */
5611 +#ifdef CONFIG_SCHED_SMT
5612 + for_each_cpu(i, cpu_map) {
5613 + struct sched_domain *sd = &per_cpu(cpu_domains, i).sd;
5614 +
5615 + init_sched_groups_power(i, sd);
5616 + }
5617 +#endif
5618 +#ifdef CONFIG_SCHED_MC
5619 + for_each_cpu(i, cpu_map) {
5620 + struct sched_domain *sd = &per_cpu(core_domains, i).sd;
5621 +
5622 + init_sched_groups_power(i, sd);
5623 + }
5624 +#endif
5625 +
5626 + for_each_cpu(i, cpu_map) {
5627 + struct sched_domain *sd = &per_cpu(phys_domains, i).sd;
5628 +
5629 + init_sched_groups_power(i, sd);
5630 + }
5631 +
5632 +#ifdef CONFIG_NUMA
5633 + for (i = 0; i < nr_node_ids; i++)
5634 + init_numa_sched_groups_power(sched_group_nodes[i]);
5635 +
5636 + if (sd_allnodes) {
5637 + struct sched_group *sg;
5638 +
5639 + cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
5640 + tmpmask);
5641 + init_numa_sched_groups_power(sg);
5642 + }
5643 +#endif
5644 +
5645 + /* Attach the domains */
5646 + for_each_cpu(i, cpu_map) {
5647 + struct sched_domain *sd;
5648 +#ifdef CONFIG_SCHED_SMT
5649 + sd = &per_cpu(cpu_domains, i).sd;
5650 +#elif defined(CONFIG_SCHED_MC)
5651 + sd = &per_cpu(core_domains, i).sd;
5652 +#else
5653 + sd = &per_cpu(phys_domains, i).sd;
5654 +#endif
5655 + cpu_attach_domain(sd, rd, i);
5656 + }
5657 +
5658 + err = 0;
5659 +
5660 +free_tmpmask:
5661 + free_cpumask_var(tmpmask);
5662 +free_send_covered:
5663 + free_cpumask_var(send_covered);
5664 +free_this_core_map:
5665 + free_cpumask_var(this_core_map);
5666 +free_this_sibling_map:
5667 + free_cpumask_var(this_sibling_map);
5668 +free_nodemask:
5669 + free_cpumask_var(nodemask);
5670 +free_notcovered:
5671 +#ifdef CONFIG_NUMA
5672 + free_cpumask_var(notcovered);
5673 +free_covered:
5674 + free_cpumask_var(covered);
5675 +free_domainspan:
5676 + free_cpumask_var(domainspan);
5677 +out:
5678 +#endif
5679 + return err;
5680 +
5681 +free_sched_groups:
5682 +#ifdef CONFIG_NUMA
5683 + kfree(sched_group_nodes);
5684 +#endif
5685 + goto free_tmpmask;
5686 +
5687 +#ifdef CONFIG_NUMA
5688 +error:
5689 + free_sched_groups(cpu_map, tmpmask);
5690 + free_rootdomain(rd);
5691 + goto free_tmpmask;
5692 +#endif
5693 +}
5694 +
5695 +static int build_sched_domains(const struct cpumask *cpu_map)
5696 +{
5697 + return __build_sched_domains(cpu_map, NULL);
5698 +}
5699 +
5700 +static struct cpumask *doms_cur; /* current sched domains */
5701 +static int ndoms_cur; /* number of sched domains in 'doms_cur' */
5702 +static struct sched_domain_attr *dattr_cur;
5703 + /* attribues of custom domains in 'doms_cur' */
5704 +
5705 +/*
5706 + * Special case: If a kmalloc of a doms_cur partition (array of
5707 + * cpumask) fails, then fallback to a single sched domain,
5708 + * as determined by the single cpumask fallback_doms.
5709 + */
5710 +static cpumask_var_t fallback_doms;
5711 +
5712 +/*
5713 + * arch_update_cpu_topology lets virtualized architectures update the
5714 + * cpu core maps. It is supposed to return 1 if the topology changed
5715 + * or 0 if it stayed the same.
5716 + */
5717 +int __attribute__((weak)) arch_update_cpu_topology(void)
5718 +{
5719 + return 0;
5720 +}
5721 +
5722 +/*
5723 + * Set up scheduler domains and groups. Callers must hold the hotplug lock.
5724 + * For now this just excludes isolated cpus, but could be used to
5725 + * exclude other special cases in the future.
5726 + */
5727 +static int arch_init_sched_domains(const struct cpumask *cpu_map)
5728 +{
5729 + int err;
5730 +
5731 + arch_update_cpu_topology();
5732 + ndoms_cur = 1;
5733 + doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
5734 + if (!doms_cur)
5735 + doms_cur = fallback_doms;
5736 + cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
5737 + dattr_cur = NULL;
5738 + err = build_sched_domains(doms_cur);
5739 + register_sched_domain_sysctl();
5740 +
5741 + return err;
5742 +}
5743 +
5744 +static void arch_destroy_sched_domains(const struct cpumask *cpu_map,
5745 + struct cpumask *tmpmask)
5746 +{
5747 + free_sched_groups(cpu_map, tmpmask);
5748 +}
5749 +
5750 +/*
5751 + * Detach sched domains from a group of cpus specified in cpu_map
5752 + * These cpus will now be attached to the NULL domain
5753 + */
5754 +static void detach_destroy_domains(const struct cpumask *cpu_map)
5755 +{
5756 + /* Save because hotplug lock held. */
5757 + static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
5758 + int i;
5759 +
5760 + for_each_cpu(i, cpu_map)
5761 + cpu_attach_domain(NULL, &def_root_domain, i);
5762 + synchronize_sched();
5763 + arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask));
5764 +}
5765 +
5766 +/* handle null as "default" */
5767 +static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
5768 + struct sched_domain_attr *new, int idx_new)
5769 +{
5770 + struct sched_domain_attr tmp;
5771 +
5772 + /* fast path */
5773 + if (!new && !cur)
5774 + return 1;
5775 +
5776 + tmp = SD_ATTR_INIT;
5777 + return !memcmp(cur ? (cur + idx_cur) : &tmp,
5778 + new ? (new + idx_new) : &tmp,
5779 + sizeof(struct sched_domain_attr));
5780 +}
5781 +
5782 +/*
5783 + * Partition sched domains as specified by the 'ndoms_new'
5784 + * cpumasks in the array doms_new[] of cpumasks. This compares
5785 + * doms_new[] to the current sched domain partitioning, doms_cur[].
5786 + * It destroys each deleted domain and builds each new domain.
5787 + *
5788 + * 'doms_new' is an array of cpumask's of length 'ndoms_new'.
5789 + * The masks don't intersect (don't overlap.) We should setup one
5790 + * sched domain for each mask. CPUs not in any of the cpumasks will
5791 + * not be load balanced. If the same cpumask appears both in the
5792 + * current 'doms_cur' domains and in the new 'doms_new', we can leave
5793 + * it as it is.
5794 + *
5795 + * The passed in 'doms_new' should be kmalloc'd. This routine takes
5796 + * ownership of it and will kfree it when done with it. If the caller
5797 + * failed the kmalloc call, then it can pass in doms_new == NULL &&
5798 + * ndoms_new == 1, and partition_sched_domains() will fallback to
5799 + * the single partition 'fallback_doms', it also forces the domains
5800 + * to be rebuilt.
5801 + *
5802 + * If doms_new == NULL it will be replaced with cpu_online_mask.
5803 + * ndoms_new == 0 is a special case for destroying existing domains,
5804 + * and it will not create the default domain.
5805 + *
5806 + * Call with hotplug lock held
5807 + */
5808 +/* FIXME: Change to struct cpumask *doms_new[] */
5809 +void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
5810 + struct sched_domain_attr *dattr_new)
5811 +{
5812 + int i, j, n;
5813 + int new_topology;
5814 +
5815 + mutex_lock(&sched_domains_mutex);
5816 +
5817 + /* always unregister in case we don't destroy any domains */
5818 + unregister_sched_domain_sysctl();
5819 +
5820 + /* Let architecture update cpu core mappings. */
5821 + new_topology = arch_update_cpu_topology();
5822 +
5823 + n = doms_new ? ndoms_new : 0;
5824 +
5825 + /* Destroy deleted domains */
5826 + for (i = 0; i < ndoms_cur; i++) {
5827 + for (j = 0; j < n && !new_topology; j++) {
5828 + if (cpumask_equal(&doms_cur[i], &doms_new[j])
5829 + && dattrs_equal(dattr_cur, i, dattr_new, j))
5830 + goto match1;
5831 + }
5832 + /* no match - a current sched domain not in new doms_new[] */
5833 + detach_destroy_domains(doms_cur + i);
5834 +match1:
5835 + ;
5836 + }
5837 +
5838 + if (doms_new == NULL) {
5839 + ndoms_cur = 0;
5840 + doms_new = fallback_doms;
5841 + cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
5842 + WARN_ON_ONCE(dattr_new);
5843 + }
5844 +
5845 + /* Build new domains */
5846 + for (i = 0; i < ndoms_new; i++) {
5847 + for (j = 0; j < ndoms_cur && !new_topology; j++) {
5848 + if (cpumask_equal(&doms_new[i], &doms_cur[j])
5849 + && dattrs_equal(dattr_new, i, dattr_cur, j))
5850 + goto match2;
5851 + }
5852 + /* no match - add a new doms_new */
5853 + __build_sched_domains(doms_new + i,
5854 + dattr_new ? dattr_new + i : NULL);
5855 +match2:
5856 + ;
5857 + }
5858 +
5859 + /* Remember the new sched domains */
5860 + if (doms_cur != fallback_doms)
5861 + kfree(doms_cur);
5862 + kfree(dattr_cur); /* kfree(NULL) is safe */
5863 + doms_cur = doms_new;
5864 + dattr_cur = dattr_new;
5865 + ndoms_cur = ndoms_new;
5866 +
5867 + register_sched_domain_sysctl();
5868 +
5869 + mutex_unlock(&sched_domains_mutex);
5870 +}
5871 +
5872 +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
5873 +static void arch_reinit_sched_domains(void)
5874 +{
5875 + get_online_cpus();
5876 +
5877 + /* Destroy domains first to force the rebuild */
5878 + partition_sched_domains(0, NULL, NULL);
5879 +
5880 + rebuild_sched_domains();
5881 + put_online_cpus();
5882 +}
5883 +
5884 +static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
5885 +{
5886 + unsigned int level = 0;
5887 +
5888 + if (sscanf(buf, "%u", &level) != 1)
5889 + return -EINVAL;
5890 +
5891 + /*
5892 + * level is always be positive so don't check for
5893 + * level < POWERSAVINGS_BALANCE_NONE which is 0
5894 + * What happens on 0 or 1 byte write,
5895 + * need to check for count as well?
5896 + */
5897 +
5898 + if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
5899 + return -EINVAL;
5900 +
5901 + if (smt)
5902 + sched_smt_power_savings = level;
5903 + else
5904 + sched_mc_power_savings = level;
5905 +
5906 + arch_reinit_sched_domains();
5907 +
5908 + return count;
5909 +}
5910 +
5911 +#ifdef CONFIG_SCHED_MC
5912 +static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
5913 + char *page)
5914 +{
5915 + return sprintf(page, "%u\n", sched_mc_power_savings);
5916 +}
5917 +static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
5918 + const char *buf, size_t count)
5919 +{
5920 + return sched_power_savings_store(buf, count, 0);
5921 +}
5922 +static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
5923 + sched_mc_power_savings_show,
5924 + sched_mc_power_savings_store);
5925 +#endif
5926 +
5927 +#ifdef CONFIG_SCHED_SMT
5928 +static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
5929 + char *page)
5930 +{
5931 + return sprintf(page, "%u\n", sched_smt_power_savings);
5932 +}
5933 +static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
5934 + const char *buf, size_t count)
5935 +{
5936 + return sched_power_savings_store(buf, count, 1);
5937 +}
5938 +static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
5939 + sched_smt_power_savings_show,
5940 + sched_smt_power_savings_store);
5941 +#endif
5942 +
5943 +int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
5944 +{
5945 + int err = 0;
5946 +
5947 +#ifdef CONFIG_SCHED_SMT
5948 + if (smt_capable())
5949 + err = sysfs_create_file(&cls->kset.kobj,
5950 + &attr_sched_smt_power_savings.attr);
5951 +#endif
5952 +#ifdef CONFIG_SCHED_MC
5953 + if (!err && mc_capable())
5954 + err = sysfs_create_file(&cls->kset.kobj,
5955 + &attr_sched_mc_power_savings.attr);
5956 +#endif
5957 + return err;
5958 +}
5959 +#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
5960 +
5961 +#ifndef CONFIG_CPUSETS
5962 +/*
5963 + * Add online and remove offline CPUs from the scheduler domains.
5964 + * When cpusets are enabled they take over this function.
5965 + */
5966 +static int update_sched_domains(struct notifier_block *nfb,
5967 + unsigned long action, void *hcpu)
5968 +{
5969 + switch (action) {
5970 + case CPU_ONLINE:
5971 + case CPU_ONLINE_FROZEN:
5972 + case CPU_DEAD:
5973 + case CPU_DEAD_FROZEN:
5974 + partition_sched_domains(1, NULL, NULL);
5975 + return NOTIFY_OK;
5976 +
5977 + default:
5978 + return NOTIFY_DONE;
5979 + }
5980 +}
5981 +#endif
5982 +
5983 +static int update_runtime(struct notifier_block *nfb,
5984 + unsigned long action, void *hcpu)
5985 +{
5986 + switch (action) {
5987 + case CPU_DOWN_PREPARE:
5988 + case CPU_DOWN_PREPARE_FROZEN:
5989 + return NOTIFY_OK;
5990 +
5991 + case CPU_DOWN_FAILED:
5992 + case CPU_DOWN_FAILED_FROZEN:
5993 + case CPU_ONLINE:
5994 + case CPU_ONLINE_FROZEN:
5995 + return NOTIFY_OK;
5996 +
5997 + default:
5998 + return NOTIFY_DONE;
5999 + }
6000 +}
6001 +
6002 +void __init sched_init_smp(void)
6003 +{
6004 + cpumask_var_t non_isolated_cpus;
6005 +
6006 + alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
6007 +
6008 +#if defined(CONFIG_NUMA)
6009 + sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
6010 + GFP_KERNEL);
6011 + BUG_ON(sched_group_nodes_bycpu == NULL);
6012 +#endif
6013 + get_online_cpus();
6014 + mutex_lock(&sched_domains_mutex);
6015 + arch_init_sched_domains(cpu_online_mask);
6016 + cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
6017 + if (cpumask_empty(non_isolated_cpus))
6018 + cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
6019 + mutex_unlock(&sched_domains_mutex);
6020 + put_online_cpus();
6021 +
6022 +#ifndef CONFIG_CPUSETS
6023 + /* XXX: Theoretical race here - CPU may be hotplugged now */
6024 + hotcpu_notifier(update_sched_domains, 0);
6025 +#endif
6026 +
6027 + /* RT runtime code needs to handle some hotplug events */
6028 + hotcpu_notifier(update_runtime, 0);
6029 +
6030 + /* Move init over to a non-isolated CPU */
6031 + if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
6032 + BUG();
6033 + free_cpumask_var(non_isolated_cpus);
6034 +
6035 + alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
6036 +
6037 + /*
6038 + * Assume that every added cpu gives us slightly less overall latency
6039 + * allowing us to increase the base rr_interval, but in a non linear
6040 + * fashion.
6041 + */
6042 + rr_interval *= 1 + ilog2(num_online_cpus());
6043 +}
6044 +#else
6045 +void __init sched_init_smp(void)
6046 +{
6047 +}
6048 +#endif /* CONFIG_SMP */
6049 +
6050 +unsigned int sysctl_timer_migration = 1;
6051 +
6052 +int in_sched_functions(unsigned long addr)
6053 +{
6054 + return in_lock_functions(addr) ||
6055 + (addr >= (unsigned long)__sched_text_start
6056 + && addr < (unsigned long)__sched_text_end);
6057 +}
6058 +
6059 +void __init sched_init(void)
6060 +{
6061 + int i;
6062 + int highest_cpu = 0;
6063 +
6064 + prio_ratios[0] = 100;
6065 + for (i = 1 ; i < PRIO_RANGE ; i++)
6066 + prio_ratios[i] = prio_ratios[i - 1] * 11 / 10;
6067 +
6068 +#ifdef CONFIG_SMP
6069 + init_defrootdomain();
6070 + cpus_clear(grq.cpu_idle_map);
6071 +#endif
6072 + spin_lock_init(&grq.lock);
6073 + for_each_possible_cpu(i) {
6074 + struct rq *rq;
6075 +
6076 + rq = cpu_rq(i);
6077 + INIT_LIST_HEAD(&rq->queue);
6078 + rq->rq_deadline = 0;
6079 + rq->rq_prio = 0;
6080 + rq->cpu = i;
6081 + rq->user_pc = rq->nice_pc = rq->softirq_pc = rq->system_pc =
6082 + rq->iowait_pc = rq->idle_pc = 0;
6083 +#ifdef CONFIG_SMP
6084 + rq->sd = NULL;
6085 + rq->rd = NULL;
6086 + rq->online = 0;
6087 + INIT_LIST_HEAD(&rq->migration_queue);
6088 + rq_attach_root(rq, &def_root_domain);
6089 +#endif
6090 + atomic_set(&rq->nr_iowait, 0);
6091 + highest_cpu = i;
6092 + }
6093 + grq.iso_ticks = grq.nr_running = grq.nr_uninterruptible = 0;
6094 + for (i = 0; i < PRIO_LIMIT; i++)
6095 + INIT_LIST_HEAD(grq.queue + i);
6096 + bitmap_zero(grq.prio_bitmap, PRIO_LIMIT);
6097 + /* delimiter for bitsearch */
6098 + __set_bit(PRIO_LIMIT, grq.prio_bitmap);
6099 +
6100 +#ifdef CONFIG_SMP
6101 + nr_cpu_ids = highest_cpu + 1;
6102 +#endif
6103 +
6104 +#ifdef CONFIG_PREEMPT_NOTIFIERS
6105 + INIT_HLIST_HEAD(&init_task.preempt_notifiers);
6106 +#endif
6107 +
6108 +#ifdef CONFIG_RT_MUTEXES
6109 + plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
6110 +#endif
6111 +
6112 + /*
6113 + * The boot idle thread does lazy MMU switching as well:
6114 + */
6115 + atomic_inc(&init_mm.mm_count);
6116 + enter_lazy_tlb(&init_mm, current);
6117 +
6118 + /*
6119 + * Make us the idle thread. Technically, schedule() should not be
6120 + * called from this thread, however somewhere below it might be,
6121 + * but because we are the idle thread, we just pick up running again
6122 + * when this runqueue becomes "idle".
6123 + */
6124 + init_idle(current, smp_processor_id());
6125 +
6126 + /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
6127 + alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
6128 +#ifdef CONFIG_SMP
6129 +#ifdef CONFIG_NO_HZ
6130 + alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
6131 + alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
6132 +#endif
6133 + alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
6134 +#endif /* SMP */
6135 + perf_counter_init();
6136 +}
6137 +
6138 +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
6139 +void __might_sleep(char *file, int line)
6140 +{
6141 +#ifdef in_atomic
6142 + static unsigned long prev_jiffy; /* ratelimiting */
6143 +
6144 + if ((in_atomic() || irqs_disabled()) &&
6145 + system_state == SYSTEM_RUNNING && !oops_in_progress) {
6146 + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
6147 + return;
6148 + prev_jiffy = jiffies;
6149 + printk(KERN_ERR "BUG: sleeping function called from invalid"
6150 + " context at %s:%d\n", file, line);
6151 + printk("in_atomic():%d, irqs_disabled():%d\n",
6152 + in_atomic(), irqs_disabled());
6153 + debug_show_held_locks(current);
6154 + if (irqs_disabled())
6155 + print_irqtrace_events(current);
6156 + dump_stack();
6157 + }
6158 +#endif
6159 +}
6160 +EXPORT_SYMBOL(__might_sleep);
6161 +#endif
6162 +
6163 +#ifdef CONFIG_MAGIC_SYSRQ
6164 +void normalize_rt_tasks(void)
6165 +{
6166 + struct task_struct *g, *p;
6167 + unsigned long flags;
6168 + struct rq *rq;
6169 + int queued;
6170 +
6171 + read_lock_irq(&tasklist_lock);
6172 +
6173 + do_each_thread(g, p) {
6174 + if (!rt_task(p) && !iso_task(p))
6175 + continue;
6176 +
6177 + spin_lock_irqsave(&p->pi_lock, flags);
6178 + rq = __task_grq_lock(p);
6179 + update_rq_clock(rq);
6180 +
6181 + queued = task_queued_only(p);
6182 + if (queued)
6183 + dequeue_task(p);
6184 + __setscheduler(p, SCHED_NORMAL, 0);
6185 + if (task_running(p))
6186 + resched_task(p);
6187 + if (queued) {
6188 + enqueue_task(p);
6189 + try_preempt(p);
6190 + }
6191 +
6192 + __task_grq_unlock();
6193 + spin_unlock_irqrestore(&p->pi_lock, flags);
6194 + } while_each_thread(g, p);
6195 +
6196 + read_unlock_irq(&tasklist_lock);
6197 +}
6198 +#endif /* CONFIG_MAGIC_SYSRQ */
6199 +
6200 +#ifdef CONFIG_IA64
6201 +/*
6202 + * These functions are only useful for the IA64 MCA handling.
6203 + *
6204 + * They can only be called when the whole system has been
6205 + * stopped - every CPU needs to be quiescent, and no scheduling
6206 + * activity can take place. Using them for anything else would
6207 + * be a serious bug, and as a result, they aren't even visible
6208 + * under any other configuration.
6209 + */
6210 +
6211 +/**
6212 + * curr_task - return the current task for a given cpu.
6213 + * @cpu: the processor in question.
6214 + *
6215 + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
6216 + */
6217 +struct task_struct *curr_task(int cpu)
6218 +{
6219 + return cpu_curr(cpu);
6220 +}
6221 +
6222 +/**
6223 + * set_curr_task - set the current task for a given cpu.
6224 + * @cpu: the processor in question.
6225 + * @p: the task pointer to set.
6226 + *
6227 + * Description: This function must only be used when non-maskable interrupts
6228 + * are serviced on a separate stack. It allows the architecture to switch the
6229 + * notion of the current task on a cpu in a non-blocking manner. This function
6230 + * must be called with all CPU's synchronized, and interrupts disabled, the
6231 + * and caller must save the original value of the current task (see
6232 + * curr_task() above) and restore that value before reenabling interrupts and
6233 + * re-starting the system.
6234 + *
6235 + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
6236 + */
6237 +void set_curr_task(int cpu, struct task_struct *p)
6238 +{
6239 + cpu_curr(cpu) = p;
6240 +}
6241 +
6242 +#endif
6243 +
6244 +/*
6245 + * Use precise platform statistics if available:
6246 + */
6247 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING
6248 +cputime_t task_utime(struct task_struct *p)
6249 +{
6250 + return p->utime;
6251 +}
6252 +
6253 +cputime_t task_stime(struct task_struct *p)
6254 +{
6255 + return p->stime;
6256 +}
6257 +#else
6258 +cputime_t task_utime(struct task_struct *p)
6259 +{
6260 + clock_t utime = cputime_to_clock_t(p->utime),
6261 + total = utime + cputime_to_clock_t(p->stime);
6262 + u64 temp;
6263 +
6264 + temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
6265 +
6266 + if (total) {
6267 + temp *= utime;
6268 + do_div(temp, total);
6269 + }
6270 + utime = (clock_t)temp;
6271 +
6272 + p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
6273 + return p->prev_utime;
6274 +}
6275 +
6276 +cputime_t task_stime(struct task_struct *p)
6277 +{
6278 + clock_t stime;
6279 +
6280 + stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
6281 + cputime_to_clock_t(task_utime(p));
6282 +
6283 + if (stime >= 0)
6284 + p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
6285 +
6286 + return p->prev_stime;
6287 +}
6288 +#endif
6289 +
6290 +inline cputime_t task_gtime(struct task_struct *p)
6291 +{
6292 + return p->gtime;
6293 +}
6294 +
6295 +void __cpuinit init_idle_bootup_task(struct task_struct *idle)
6296 +{}
6297 +
6298 +#ifdef CONFIG_SCHED_DEBUG
6299 +void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
6300 +{}
6301 +
6302 +void proc_sched_set_task(struct task_struct *p)
6303 +{}
6304 +#endif
6305 --- a/kernel/sysctl.c
6306 +++ b/kernel/sysctl.c
6307 @@ -83,6 +83,8 @@ extern int percpu_pagelist_fraction;
6308 extern int compat_log;
6309 extern int latencytop_enabled;
6310 extern int sysctl_nr_open_min, sysctl_nr_open_max;
6311 +extern int rr_interval;
6312 +extern int sched_iso_cpu;
6313 #ifndef CONFIG_MMU
6314 extern int sysctl_nr_trim_pages;
6315 #endif
6316 @@ -100,7 +102,8 @@ static int zero;
6317 static int __maybe_unused one = 1;
6318 static int __maybe_unused two = 2;
6319 static unsigned long one_ul = 1;
6320 -static int one_hundred = 100;
6321 +static int __read_mostly one_hundred = 100;
6322 +static int __maybe_unused __read_mostly five_thousand = 5000;
6323
6324 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
6325 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
6326 @@ -234,7 +237,7 @@ static struct ctl_table root_table[] = {
6327 { .ctl_name = 0 }
6328 };
6329
6330 -#ifdef CONFIG_SCHED_DEBUG
6331 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
6332 static int min_sched_granularity_ns = 100000; /* 100 usecs */
6333 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
6334 static int min_wakeup_granularity_ns; /* 0 usecs */
6335 @@ -242,7 +245,7 @@ static int max_wakeup_granularity_ns = N
6336 #endif
6337
6338 static struct ctl_table kern_table[] = {
6339 -#ifdef CONFIG_SCHED_DEBUG
6340 +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
6341 {
6342 .ctl_name = CTL_UNNUMBERED,
6343 .procname = "sched_min_granularity_ns",
6344 @@ -327,6 +330,7 @@ static struct ctl_table kern_table[] = {
6345 .proc_handler = &proc_dointvec,
6346 },
6347 #endif
6348 +#ifdef CONFIG_SCHED_CFS
6349 {
6350 .ctl_name = CTL_UNNUMBERED,
6351 .procname = "sched_rt_period_us",
6352 @@ -351,6 +355,7 @@ static struct ctl_table kern_table[] = {
6353 .mode = 0644,
6354 .proc_handler = &proc_dointvec,
6355 },
6356 +#endif
6357 #ifdef CONFIG_PROVE_LOCKING
6358 {
6359 .ctl_name = CTL_UNNUMBERED,
6360 @@ -756,6 +761,30 @@ static struct ctl_table kern_table[] = {
6361 .proc_handler = &proc_dointvec,
6362 },
6363 #endif
6364 +#ifdef CONFIG_SCHED_BFS
6365 + {
6366 + .ctl_name = CTL_UNNUMBERED,
6367 + .procname = "rr_interval",
6368 + .data = &rr_interval,
6369 + .maxlen = sizeof (int),
6370 + .mode = 0644,
6371 + .proc_handler = &proc_dointvec_minmax,
6372 + .strategy = &sysctl_intvec,
6373 + .extra1 = &one,
6374 + .extra2 = &five_thousand,
6375 + },
6376 + {
6377 + .ctl_name = CTL_UNNUMBERED,
6378 + .procname = "iso_cpu",
6379 + .data = &sched_iso_cpu,
6380 + .maxlen = sizeof (int),
6381 + .mode = 0644,
6382 + .proc_handler = &proc_dointvec_minmax,
6383 + .strategy = &sysctl_intvec,
6384 + .extra1 = &zero,
6385 + .extra2 = &one_hundred,
6386 + },
6387 +#endif
6388 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
6389 {
6390 .ctl_name = KERN_SPIN_RETRY,
6391 --- a/kernel/workqueue.c
6392 +++ b/kernel/workqueue.c
6393 @@ -320,7 +320,9 @@ static int worker_thread(void *__cwq)
6394 if (cwq->wq->freezeable)
6395 set_freezable();
6396
6397 +#ifdef CONFIG_SCHED_CFS
6398 set_user_nice(current, -5);
6399 +#endif
6400
6401 for (;;) {
6402 prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
6403 --- /dev/null
6404 +++ b/include/linux/perf_counter.h
6405 @@ -0,0 +1,2 @@
6406 +#define perf_counter_init() do {} while(0)
6407 +#define perf_counter_task_sched_in(...) do {} while(0)
6408 --- /dev/null
6409 +++ b/include/trace/events/sched.h
6410 @@ -0,0 +1 @@
6411 +#include <trace/sched.h>
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