[PATCH 2/2] android, lmk: Reverse the order of setting TIF_MEMDIE and sending SIGKILL.
Tetsuo Handa
penguin-kernel at I-love.SAKURA.ne.jp
Fri Sep 4 18:06:46 UTC 2015
Greg KH wrote:
> On Fri, Sep 04, 2015 at 04:05:59PM +0200, Michal Hocko wrote:
> > On Wed 02-09-15 18:06:20, Greg KH wrote:
> > [...]
> > > And if we aren't taking patch 1/2, I guess this one isn't needed either?
> >
> > Unlike the patch1 which was pretty much cosmetic this fixes a real
> > issue.
>
> Ok, then it would be great to get this in a format that I can apply it
> in :)
I see. Here is a minimal patch.
(Acked-by: from http://lkml.kernel.org/r/20150827084443.GE14367@dhcp22.suse.cz )
----------------------------------------
>From 118609fa25700af11791b1b7e8349f8973a9e7e4 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
Date: Sat, 5 Sep 2015 02:58:12 +0900
Subject: [PATCH] android, lmk: Send SIGKILL before setting TIF_MEMDIE.
It was observed that setting TIF_MEMDIE before sending SIGKILL at
oom_kill_process() allows memory reserves to be depleted by allocations
which are not needed for terminating the OOM victim.
This patch reverts commit 6bc2b856bb7c ("staging: android: lowmemorykiller:
set TIF_MEMDIE before send kill sig"), for oom_kill_process() was updated
to send SIGKILL before setting TIF_MEMDIE.
Signed-off-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko at suse.com>
---
drivers/staging/android/lowmemorykiller.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index 872bd60..569d12c 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -157,26 +157,22 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
}
if (selected) {
task_lock(selected);
- if (!selected->mm) {
- /* Already exited, cannot do mark_tsk_oom_victim() */
- task_unlock(selected);
- goto out;
- }
+ send_sig(SIGKILL, selected, 0);
/*
* FIXME: lowmemorykiller shouldn't abuse global OOM killer
* infrastructure. There is no real reason why the selected
* task should have access to the memory reserves.
*/
- mark_oom_victim(selected);
+ if (selected->mm)
+ mark_oom_victim(selected);
task_unlock(selected);
lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize);
lowmem_deathpending_timeout = jiffies + HZ;
- send_sig(SIGKILL, selected, 0);
rem += selected_tasksize;
}
-out:
+
lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
sc->nr_to_scan, sc->gfp_mask, rem);
rcu_read_unlock();
--
1.8.3.1
More information about the devel
mailing list