From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757012AbbJAMui (ORCPT <rfc822;w@1wt.eu>);
	Thu, 1 Oct 2015 08:50:38 -0400
Received: from mail-wi0-f179.google.com ([209.85.212.179]:35509 "EHLO
	mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756987AbbJAMud (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 1 Oct 2015 08:50:33 -0400
Date: Thu, 1 Oct 2015 14:50:31 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        David Rientjes <rientjes@google.com>, Kyle Walker <kwalker@redhat.com>,
        Stanislav Kozina <skozina@redhat.com>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm v2 2/3] mm/oom_kill: cleanup the "kill sharing same
 memory" loop
Message-ID: <20151001125030.GD24077@dhcp22.suse.cz>
References: <20150930182341.GA15047@redhat.com>
 <20150930182408.GA15247@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20150930182408.GA15247@redhat.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed 30-09-15 20:24:08, Oleg Nesterov wrote:
> Purely cosmetic, but the complex "if" condition looks annoying to me.
> Especially because it is not consistent with OOM_SCORE_ADJ_MIN check
> which adds another if/continue.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/oom_kill.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index b6b8c78..c189ee5 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -583,14 +583,18 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
>  	 * pending fatal signal.
>  	 */
>  	rcu_read_lock();
> -	for_each_process(p)
> -		if (p->mm == mm && !same_thread_group(p, victim) &&
> -		    !(p->flags & PF_KTHREAD)) {
> -			if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
> -				continue;
> +	for_each_process(p) {
> +		if (p->mm != mm)
> +			continue;
> +		if (same_thread_group(p, victim))
> +			continue;
> +		if (unlikely(p->flags & PF_KTHREAD))
> +			continue;
> +		if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
> +			continue;
>  
> -			do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
> -		}
> +		do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
> +	}
>  	rcu_read_unlock();
>  
>  	mmput(mm);
> -- 
> 2.4.3

-- 
Michal Hocko
SUSE Labs