lustre/kernel_patches/patches/md-rebuild-policy.patch

   1 Index: linux-2.6.18-128.1.6/drivers/md/md.c
   2 ===================================================================
   3 --- linux-2.6.18-128.1.6.orig/drivers/md/md.c   2009-04-14 21:05:26.000000000 -0600
   4 +++ linux-2.6.18-128.1.6/drivers/md/md.c        2009-06-02 23:25:31.000000000 -0600
   5 @@ -90,6 +90,8 @@
   6
   7  static int sysctl_speed_limit_min = 1000;
   8  static int sysctl_speed_limit_max = 200000;
   9 +static int sysctl_rebuild_window_size = 256;
  10 +static int sysctl_disk_idle_size = 4096;
  11  static inline int speed_min(mddev_t *mddev)
  12  {
  13         return mddev->sync_speed_min ?
  14 @@ -121,6 +123,22 @@
  15                 .mode           = S_IRUGO|S_IWUSR,
  16                 .proc_handler   = &proc_dointvec,
  17         },
  18 +       {
  19 +               .ctl_name       = DEV_RAID_REBUILD_WINDOW,
  20 +               .procname       = "rebuild_window_size",
  21 +               .data           = &sysctl_rebuild_window_size,
  22 +               .maxlen         = sizeof(int),
  23 +               .mode           = S_IRUGO|S_IWUSR,
  24 +               .proc_handler   = &proc_dointvec,
  25 +       },
  26 +       {
  27 +               .ctl_name       = DEV_RAID_DISK_IDLE_SIZE,
  28 +               .procname       = "disk_idle_size",
  29 +               .data           = &sysctl_disk_idle_size,
  30 +               .maxlen         = sizeof(int),
  31 +               .mode           = S_IRUGO|S_IWUSR,
  32 +               .proc_handler   = &proc_dointvec,
  33 +       },
  34         { .ctl_name = 0 }
  35  };
  36
  37 @@ -5009,15 +5027,16 @@
  38  {
  39         mdk_rdev_t * rdev;
  40         int idle;
  41 -       unsigned long curr_events;
  42 +       unsigned long rw, sync;
  43
  44         idle = 1;
  45         rcu_read_lock();
  46         rdev_for_each_rcu(rdev, mddev) {
  47                 struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
  48 -               curr_events = disk_stat_read(disk, sectors[0]) +
  49 -                               disk_stat_read(disk, sectors[1]) -
  50 -                               atomic_read(&disk->sync_io);
  51 +
  52 +               rw = disk_stat_read(disk, sectors[READ])+disk_stat_read(disk, sectors[WRITE]);
  53 +               sync = atomic_read(&disk->sync_io);
  54 +
  55                 /* The difference between curr_events and last_events
  56                  * will be affected by any new non-sync IO (making
  57                  * curr_events bigger) and any difference in the amount of
  58 @@ -5031,9 +5050,9 @@
  59                  *
  60                  * Note: the following is an unsigned comparison.
  61                  */
  62 -               if ((curr_events - rdev->last_events + 4096) > 8192) {
  63 -                       rdev->last_events = curr_events;
  64 +               if (rw - rdev->last_events > sync + sysctl_disk_idle_size) {
  65                         idle = 0;
  66 +                       rdev->last_events = rw - sync;
  67                 }
  68         }
  69         rcu_read_unlock();
  70 @@ -5100,8 +5119,7 @@
  71  void md_do_sync(mddev_t *mddev)
  72  {
  73         mddev_t *mddev2;
  74 -       unsigned int currspeed = 0,
  75 -                window;
  76 +       unsigned int currspeed = 0;
  77         sector_t max_sectors,j, io_sectors;
  78         unsigned long mark[SYNC_MARKS];
  79         sector_t mark_cnt[SYNC_MARKS];
  80 @@ -5221,9 +5239,8 @@
  81         /*
  82          * Tune reconstruction:
  83          */
  84 -       window = 32*(PAGE_SIZE/512);
  85         printk(KERN_INFO "md: using %dk window, over a total of %llu blocks.\n",
  86 -               window/2,(unsigned long long) max_sectors/2);
  87 +               sysctl_rebuild_window_size/2,(unsigned long long) max_sectors/2);
  88
  89         atomic_set(&mddev->recovery_active, 0);
  90         init_waitqueue_head(&mddev->recovery_wait);
  91 @@ -5261,7 +5278,7 @@
  92                          */
  93                         md_new_event(mddev);
  94
  95 -               if (last_check + window > io_sectors || j == max_sectors)
  96 +               if (last_check + sysctl_rebuild_window_size > io_sectors || j == max_sectors)
  97                         continue;
  98
  99                 last_check = io_sectors;
 100 @@ -5282,7 +5299,6 @@
 101                         last_mark = next;
 102                 }
 103
 104 -
 105                 if (kthread_should_stop()) {
 106                         /*
 107                          * got a signal, exit.
 108 @@ -5306,10 +5322,16 @@
 109
 110                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
 111                         /((jiffies-mddev->resync_mark)/HZ +1) +1;
 112 -
 113                 if (currspeed > speed_min(mddev)) {
 114                         if ((currspeed > speed_max(mddev)) ||
 115                                         !is_mddev_idle(mddev)) {
 116 +                               static unsigned long next_report;
 117 +                               if (time_after(jiffies, next_report)) {
 118 +                                       printk(KERN_INFO "md: rebuild %s throttled due to IO\n",
 119 +                                               mdname(mddev));
 120 +                                       /* once per 10 minutes */
 121 +                                       next_report = jiffies + 600 * HZ;
 122 +                               }
 123                                 msleep(500);
 124                                 goto repeat;
 125                         }
 126 Index: linux-2.6.18-128.1.6/include/linux/sysctl.h
 127 ===================================================================
 128 --- linux-2.6.18-128.1.6.orig/include/linux/sysctl.h    2009-04-14 21:05:41.000000000 -0600
 129 +++ linux-2.6.18-128.1.6/include/linux/sysctl.h 2009-06-02 23:25:31.000000000 -0600
 130 @@ -928,7 +928,9 @@
 131  /* /proc/sys/dev/raid */
 132  enum {
 133         DEV_RAID_SPEED_LIMIT_MIN=1,
 134 -       DEV_RAID_SPEED_LIMIT_MAX=2
 135 +       DEV_RAID_SPEED_LIMIT_MAX=2,
 136 +       DEV_RAID_REBUILD_WINDOW=3,
 137 +       DEV_RAID_DISK_IDLE_SIZE=4
 138  };
 139
 140  /* /proc/sys/dev/parport/default */