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| author | Vladimir Davydov <vdavydov@virtuozzo.com> | 2016-03-25 14:20:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-25 16:37:42 -0700 |
| commit | 29c696e1c6eceb5db6b21f0c89495fcfcd40c0eb (patch) | |
| tree | fe5a096de3c34d3fef0fcc40dd3fbc03a99599a1 | |
| parent | 855b018325737f7691f9b7d86339df40aa4e47c3 (diff) | |
| download | linux-29c696e1c6eceb5db6b21f0c89495fcfcd40c0eb.tar.bz2 | |
oom: make oom_reaper_list single linked
Entries are only added/removed from oom_reaper_list at head so we can
use a single linked list and hence save a word in task_struct.
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | mm/oom_kill.c | 15 |
2 files changed, 8 insertions, 9 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index c2d2d7c5d463..49b1febcf7c3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1852,7 +1852,7 @@ struct task_struct { #endif int pagefault_disabled; #ifdef CONFIG_MMU - struct list_head oom_reaper_list; + struct task_struct *oom_reaper_list; #endif /* CPU-specific state of this task */ struct thread_struct thread; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 1a21819a8e5e..a49638f41e45 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -419,7 +419,7 @@ bool oom_killer_disabled __read_mostly; */ static struct task_struct *oom_reaper_th; static DECLARE_WAIT_QUEUE_HEAD(oom_reaper_wait); -static LIST_HEAD(oom_reaper_list); +static struct task_struct *oom_reaper_list; static DEFINE_SPINLOCK(oom_reaper_lock); @@ -528,13 +528,11 @@ static int oom_reaper(void *unused) while (true) { struct task_struct *tsk = NULL; - wait_event_freezable(oom_reaper_wait, - (!list_empty(&oom_reaper_list))); + wait_event_freezable(oom_reaper_wait, oom_reaper_list != NULL); spin_lock(&oom_reaper_lock); - if (!list_empty(&oom_reaper_list)) { - tsk = list_first_entry(&oom_reaper_list, - struct task_struct, oom_reaper_list); - list_del(&tsk->oom_reaper_list); + if (oom_reaper_list != NULL) { + tsk = oom_reaper_list; + oom_reaper_list = tsk->oom_reaper_list; } spin_unlock(&oom_reaper_lock); @@ -553,7 +551,8 @@ static void wake_oom_reaper(struct task_struct *tsk) get_task_struct(tsk); spin_lock(&oom_reaper_lock); - list_add(&tsk->oom_reaper_list, &oom_reaper_list); + tsk->oom_reaper_list = oom_reaper_list; + oom_reaper_list = tsk; spin_unlock(&oom_reaper_lock); wake_up(&oom_reaper_wait); } |