From: Tetsuo Handa Date: Sun, 6 Sep 2015 05:25:35 +0000 (+0900) Subject: android, lmk: Send SIGKILL before setting TIF_MEMDIE. X-Git-Tag: firefly_0821_release~176^2~802^2~1160 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3a81fc20eadcf193a4517fd5ee862c3d465aceb3;p=firefly-linux-kernel-4.4.55.git 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 Acked-by: Michal Hocko Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index 872bd603fd0d..569d12c02877 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();