From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id E233E6B02C3 for ; Mon, 5 Jun 2017 01:12:10 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id n7so484298wrb.0 for ; Sun, 04 Jun 2017 22:12:10 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id o6si20931196wrc.161.2017.06.04.22.12.09 for (version=TLS1 cipher=AES128-SHA bits=128/128); Sun, 04 Jun 2017 22:12:09 -0700 (PDT) Date: Mon, 5 Jun 2017 07:12:07 +0200 From: Michal Hocko Subject: Re: [PATCH v2] swap: cond_resched in swap_cgroup_prepare() Message-ID: <20170605051206.GB9248@dhcp22.suse.cz> References: <20170601195635.20744-1-yuzhao@google.com> <20170604200109.17606-1-yuzhao@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170604200109.17606-1-yuzhao@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Yu Zhao Cc: Johannes Weiner , Vladimir Davydov , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton [CC Andrew] On Sun 04-06-17 13:01:09, Yu Zhao wrote: > Saw need_resched() warnings when swapping on large swapfile (TBs) > because continuously allocating many pages in swap_cgroup_prepare() > took too long. > > We already cond_resched when freeing page in swap_cgroup_swapoff(). > Do the same for the page allocation. > > Signed-off-by: Yu Zhao > Acked-by: Michal Hocko > Acked-by: Vladimir Davydov > --- > Changelog since v1: > * clarify the problem in the commit message > > mm/swap_cgroup.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c > index ac6318a064d3..3405b4ee1757 100644 > --- a/mm/swap_cgroup.c > +++ b/mm/swap_cgroup.c > @@ -48,6 +48,9 @@ static int swap_cgroup_prepare(int type) > if (!page) > goto not_enough_page; > ctrl->map[idx] = page; > + > + if (!(idx % SWAP_CLUSTER_MAX)) > + cond_resched(); > } > return 0; > not_enough_page: > -- > 2.13.0.506.g27d5fe0cd-goog -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org