diff options
Diffstat (limited to 'drivers/staging/android/lowmemorykiller.c')
| -rw-r--r-- | drivers/staging/android/lowmemorykiller.c | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index fe72240f5a9e..f13c6fc76c44 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -1,5 +1,21 @@ /* drivers/misc/lowmemorykiller.c * + * The lowmemorykiller driver lets user-space specify a set of memory thresholds + * where processes with a range of oom_adj values will get killed. Specify the + * minimum oom_adj values in /sys/module/lowmemorykiller/parameters/adj and the + * number of free pages in /sys/module/lowmemorykiller/parameters/minfree. Both + * files take a comma separated list of numbers in ascending order. + * + * For example, write "0,8" to /sys/module/lowmemorykiller/parameters/adj and + * "1024,4096" to /sys/module/lowmemorykiller/parameters/minfree to kill processes + * with a oom_adj value of 8 or higher when the free memory drops below 4096 pages + * and kill processes with a oom_adj value of 0 or higher when the free memory + * drops below 1024 pages. + * + * The driver considers memory used for caches to be free, but if a large + * percentage of the cached memory is locked this can be very inaccurate + * and processes may not get killed until the normal oom killer is triggered. + * * Copyright (C) 2007-2008 Google, Inc. * * This software is licensed under the terms of the GNU General Public @@ -19,12 +35,6 @@ #include <linux/oom.h> #include <linux/sched.h> -static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask); - -static struct shrinker lowmem_shrinker = { - .shrink = lowmem_shrink, - .seeks = DEFAULT_SEEKS * 16 -}; static uint32_t lowmem_debug_level = 2; static int lowmem_adj[6] = { 0, @@ -96,19 +106,21 @@ static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask) read_lock(&tasklist_lock); for_each_process(p) { + struct mm_struct *mm; int oom_adj; task_lock(p); - if (!p->mm) { + mm = p->mm; + if (!mm) { task_unlock(p); continue; } - oom_adj = p->oomkilladj; + oom_adj = mm->oom_adj; if (oom_adj < min_adj) { task_unlock(p); continue; } - tasksize = get_mm_rss(p->mm); + tasksize = get_mm_rss(mm); task_unlock(p); if (tasksize <= 0) continue; @@ -138,6 +150,11 @@ static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask) return rem; } +static struct shrinker lowmem_shrinker = { + .shrink = lowmem_shrink, + .seeks = DEFAULT_SEEKS * 16 +}; + static int __init lowmem_init(void) { register_shrinker(&lowmem_shrinker); |