From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755689AbaIWDDu (ORCPT ); Mon, 22 Sep 2014 23:03:50 -0400 Received: from mx1.mxmail.xiaomi.com ([58.68.235.87]:59928 "EHLO mx1.mxmail.xiaomi.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753650AbaIWDDs (ORCPT ); Mon, 22 Sep 2014 23:03:48 -0400 X-Greylist: delayed 367 seconds by postgrey-1.27 at vger.kernel.org; Mon, 22 Sep 2014 23:03:47 EDT From: Hui Zhu To: , , , CC: , , , Hui Zhu Subject: [PATCH] Fix the issue that lowmemkiller fell into a cycle that try to kill a task Date: Tue, 23 Sep 2014 10:57:09 +0800 Message-ID: <1411441029-8428-1-git-send-email-zhuhui@xiaomi.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.27.14.101] X-EsetResult: clean, is OK X-EsetId: B888893E9A6C9E31E8C9D8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The cause of this issue is when free memroy size is low and a lot of task is trying to shrink the memory, the task that is killed by lowmemkiller cannot get CPU to exit itself. Fix this issue with change the scheduling policy to SCHED_FIFO if a task's flag is TIF_MEMDIE in lowmemkiller. Signed-off-by: Hui Zhu --- drivers/staging/android/lowmemorykiller.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index b545d3d..ca1ffac 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -129,6 +129,10 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) if (test_tsk_thread_flag(p, TIF_MEMDIE) && time_before_eq(jiffies, lowmem_deathpending_timeout)) { + struct sched_param param = { .sched_priority = 1 }; + + if (p->policy == SCHED_NORMAL) + sched_setscheduler(p, SCHED_FIFO, ¶m); task_unlock(p); rcu_read_unlock(); return 0; -- 1.9.1