From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751030AbdLGJwa (ORCPT ); Thu, 7 Dec 2017 04:52:30 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:37420 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862AbdLGJw3 (ORCPT ); Thu, 7 Dec 2017 04:52:29 -0500 X-Google-Smtp-Source: AGs4zMaQKkxVc7O17WqQea4EqXA6PU32/hQU0xWFM0Hlvst9gOY1lti9s73a40O7qxsma9U377jQAg== Date: Thu, 7 Dec 2017 18:52:23 +0900 From: Sergey Senozhatsky To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, mhocko@suse.com, hannes@cmpxchg.org, hillf.zj@alibaba-inc.com, minchan@kernel.org, mgorman@techsingularity.net, ying.huang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, timmurray@google.com, tkjos@google.com Subject: Re: [PATCH] mm: terminate shrink_slab loop if signal is pending Message-ID: <20171207095223.GB574@jagdpanzerIV> References: <20171206192026.25133-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171206192026.25133-1-surenb@google.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (12/06/17 11:20), Suren Baghdasaryan wrote: > Slab shrinkers can be quite time consuming and when signal > is pending they can delay handling of the signal. If fatal > signal is pending there is no point in shrinking that process > since it will be killed anyway. This change checks for pending > fatal signals inside shrink_slab loop and if one is detected > terminates this loop early. > > Signed-off-by: Suren Baghdasaryan > --- > mm/vmscan.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index c02c850ea349..69296528ff33 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -486,6 +486,13 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid, > .memcg = memcg, > }; > > + /* > + * We are about to die and free our memory. > + * Stop shrinking which might delay signal handling. > + */ > + if (unlikely(fatal_signal_pending(current)) - if (unlikely(fatal_signal_pending(current)) + if (unlikely(fatal_signal_pending(current))) -ss