Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752811AbcCAJ2c (ORCPT ); Tue, 1 Mar 2016 04:28:32 -0500 Received: from mx2.parallels.com ([199.115.105.18]:34291 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870AbcCAJ2a (ORCPT ); Tue, 1 Mar 2016 04:28:30 -0500 From: Vladimir Davydov To: Andrew Morton CC: Michal Hocko , Tetsuo Handa , , Subject: [PATCH -mm] oom: make oom_reaper_list single linked Date: Tue, 1 Mar 2016 12:28:20 +0300 Message-ID: <1456824500-30661-1-git-send-email-vdavydov@virtuozzo.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Content-Type: text/plain X-ClientProxiedBy: US-EXCH2.sw.swsoft.com (10.255.249.46) To US-EXCH2.sw.swsoft.com (10.255.249.46) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2066 Lines: 65 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 --- include/linux/sched.h | 2 +- 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 2118e963fba7..7b76e65595c3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1853,7 +1853,7 @@ 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 5d5eca9d6737..1a91d9a26bc9 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -423,7 +423,7 @@ 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); @@ -530,13 +530,11 @@ 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); @@ -555,7 +553,8 @@ 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); } -- 2.1.4