package/hotplug2/patches/120-throttling.patch

   1 Index: hotplug2-0.9/hotplug2.c
   2 ===================================================================
   3 --- hotplug2-0.9.orig/hotplug2.c        2008-08-04 10:02:27.000000000 +0200
   4 +++ hotplug2-0.9/hotplug2.c     2008-08-04 10:03:04.000000000 +0200
   5 @@ -21,6 +21,7 @@
   6  #include <sys/mman.h>
   7  #include <linux/types.h>
   8  #include <linux/netlink.h>
   9 +#include <poll.h>
  10
  11  #include "mem_utils.h"
  12  #include "filemap_utils.h"
  13 @@ -492,6 +493,11 @@
  14         char *coldplug_command = NULL;
  15         char *rules_file = HOTPLUG2_RULE_PATH;
  16         sigset_t block_mask;
  17 +       struct pollfd msg_poll;
  18 +
  19 +       struct hotplug2_event_t *backlog = NULL;
  20 +       struct hotplug2_event_t *backlog_tail = NULL;
  21 +       int n_backlog = 0;
  22
  23         struct rules_t *rules = NULL;
  24         struct filemap_t filemap;
  25 @@ -602,6 +608,8 @@
  26          * Open netlink socket to read the uevents
  27          */
  28         netlink_socket = init_netlink_socket(NETLINK_BIND);
  29 +       msg_poll.fd = netlink_socket;
  30 +       msg_poll.events = POLLIN;
  31
  32         if (netlink_socket == -1) {
  33                 ERROR("netlink init","Unable to open netlink socket.");
  34 @@ -642,20 +650,44 @@
  35          * Main loop reading uevents
  36          */
  37         while (!terminate) {
  38 -               /*
  39 -                * Read the uevent packet
  40 -                */
  41 -               size = recv(netlink_socket, &buffer, sizeof(buffer), 0);
  42 -               recv_errno = errno;
  43 +               if ((n_backlog > 0) && (child_c < max_child_c)) {
  44 +                       /* dequeue backlog message */
  45 +                       tmpevent = backlog;
  46 +                       backlog = backlog->next;
  47 +                       n_backlog--;
  48 +                       if (backlog_tail == tmpevent)
  49 +                               backlog_tail = NULL;
  50 +               } else {
  51 +                       /*
  52 +                        * Read the uevent packet
  53 +                        */
  54 +                       if (n_backlog >= HOTPLUG2_MSG_BACKLOG) {
  55 +                               usleep(HOTPLUG2_THROTTLE_INTERVAL * 1000);
  56 +                               continue;
  57 +                       }
  58 +
  59 +                       if ((n_backlog > 0) && (child_c >= max_child_c)) {
  60 +                               int fds;
  61 +                               msg_poll.revents = 0;
  62 +                               fds = poll(&msg_poll, 1, HOTPLUG2_THROTTLE_INTERVAL);
  63 +                               if (fds < 0) {
  64 +                                       continue;
  65 +                               }
  66 +                               if (fds == 0)
  67 +                                       continue;
  68 +                       }
  69 +                       size = recv(netlink_socket, &buffer, sizeof(buffer), 0);
  70 +                       recv_errno = errno;
  71
  72 -               /*
  73 -                * Parse the event into an event structure
  74 -                */
  75 -               tmpevent = get_hotplug2_event(buffer, size);
  76 +                       /*
  77 +                        * Parse the event into an event structure
  78 +                        */
  79 +                       tmpevent = get_hotplug2_event(buffer, size);
  80
  81 -               if (tmpevent == NULL) {
  82 -                       ERROR("reading events", "Malformed event read (missing action prefix).");
  83 -                       continue;
  84 +                       if (tmpevent == NULL) {
  85 +                               ERROR("reading events", "Malformed event read (missing action prefix).");
  86 +                               continue;
  87 +                       }
  88                 }
  89
  90                 /*
  91 @@ -706,13 +738,16 @@
  92                          * Unless, of course, we've specified otherwise and no rules that match
  93                          * need throttling.
  94                          */
  95 -                       if (!flags & FLAG_NOTHROTTLE) {
  96 -                               /*
  97 -                                * Okay, throttle away!
  98 -                                */
  99 -                               while (child_c >= max_child_c) {
 100 -                                       usleep(HOTPLUG2_THROTTLE_INTERVAL);
 101 -                               }
 102 +                       if (!(flags & FLAG_NOTHROTTLE) && (child_c >= max_child_c)) {
 103 +                               /* log the packet and process it later */
 104 +                               if (backlog_tail)
 105 +                                       backlog_tail->next = tmpevent;
 106 +                               else
 107 +                                       backlog = tmpevent;
 108 +                               tmpevent->next = NULL;
 109 +                               backlog_tail = tmpevent;
 110 +                               n_backlog++;
 111 +                               continue;
 112                         }
 113
 114                         sigemptyset(&block_mask);
 115 Index: hotplug2-0.9/hotplug2.h
 116 ===================================================================
 117 --- hotplug2-0.9.orig/hotplug2.h        2008-08-04 10:02:27.000000000 +0200
 118 +++ hotplug2-0.9/hotplug2.h     2008-08-04 10:02:27.000000000 +0200
 119 @@ -45,9 +45,9 @@
 120  #define DBG(action, fmt, arg...)
 121  #endif
 122
 123 +#define HOTPLUG2_MSG_BACKLOG   64
 124  #define UEVENT_BUFFER_SIZE             2048
 125 -#define HOTPLUG2_POLL_INTERVAL         20000
 126 -#define HOTPLUG2_THROTTLE_INTERVAL     10000
 127 +#define HOTPLUG2_THROTTLE_INTERVAL     50
 128  #define HOTPLUG2_RULE_PATH             "/etc/hotplug2.rules"
 129
 130  #define ACTION_ADD                     0
 131 @@ -76,6 +76,7 @@
 132         int env_vars_c;
 133         char *plain;
 134         int plain_s;
 135 +       struct hotplug2_event_t *next;
 136  };
 137
 138  struct options_t {