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| author | Anton Vorontsov <anton.vorontsov@linaro.org> | 2012-02-06 20:29:47 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-08 16:55:45 -0800 |
| commit | 95670001188911f9d466875cd68e3681f39df38a (patch) | |
| tree | 9610b1dc93b48119d69a422348bc867f2139757f | |
| parent | 294b27119f2e20643e71a0c1a1b511320a11e4c3 (diff) | |
| download | linux-95670001188911f9d466875cd68e3681f39df38a.tar.gz linux-95670001188911f9d466875cd68e3681f39df38a.tar.bz2 linux-95670001188911f9d466875cd68e3681f39df38a.zip | |
staging: android/lowmemorykiller: Better mm handling
LMK should not directly check for task->mm. The reason is that the
process' threads may exit or detach its mm via use_mm(), but other
threads may still have a valid mm. To catch this we use
find_lock_task_mm(), which walks up all threads and returns an
appropriate task (with lock held).
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/android/lowmemorykiller.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index 63da8447218f..0755e2f0eb18 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -82,7 +82,7 @@ task_notify_func(struct notifier_block *self, unsigned long val, void *data) static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) { - struct task_struct *p; + struct task_struct *tsk; struct task_struct *selected = NULL; int rem = 0; int tasksize; @@ -134,15 +134,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) selected_oom_adj = min_adj; rcu_read_lock(); - for_each_process(p) { - struct mm_struct *mm; + for_each_process(tsk) { + struct task_struct *p; struct signal_struct *sig; int oom_adj; - task_lock(p); - mm = p->mm; + p = find_lock_task_mm(tsk); + if (!p) + continue; + sig = p->signal; - if (!mm || !sig) { + if (!sig) { task_unlock(p); continue; } @@ -151,7 +153,7 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) task_unlock(p); continue; } - tasksize = get_mm_rss(mm); + tasksize = get_mm_rss(p->mm); task_unlock(p); if (tasksize <= 0) continue; |