From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753856AbdCBDdm (ORCPT ); Wed, 1 Mar 2017 22:33:42 -0500 Received: from out4433.biz.mail.alibaba.com ([47.88.44.33]:26127 "EHLO out4433.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753447AbdCBDdk (ORCPT ); Wed, 1 Mar 2017 22:33:40 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03302;MF=hillf.zj@alibaba-inc.com;NM=1;PH=DS;RN=8;SC=85;SR=0;TI=SMTPD_---.7jkq0DP_1488425461; Reply-To: "Hillf Danton" From: "Hillf Danton" To: "'Johannes Weiner'" , "'Andrew Morton'" Cc: "'Jia He'" , "'Michal Hocko'" , "'Mel Gorman'" , , , References: <20170228214007.5621-1-hannes@cmpxchg.org> <20170228214007.5621-6-hannes@cmpxchg.org> In-Reply-To: <20170228214007.5621-6-hannes@cmpxchg.org> Subject: Re: [PATCH 5/9] mm: don't avoid high-priority reclaim on unreclaimable nodes Date: Thu, 02 Mar 2017 11:31:01 +0800 Message-ID: <078001d29305$6ae1fb00$40a5f100$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQGushofxnzLnyVlk/YQjboYC5yEOwGNg85aobw6LDA= Content-Language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On March 01, 2017 5:40 AM Johannes Weiner wrote: > > 246e87a93934 ("memcg: fix get_scan_count() for small targets") sought > to avoid high reclaim priorities for kswapd by forcing it to scan a > minimum amount of pages when lru_pages >> priority yielded nothing. > > b95a2f2d486d ("mm: vmscan: convert global reclaim to per-memcg LRU > lists"), due to switching global reclaim to a round-robin scheme over > all cgroups, had to restrict this forceful behavior to unreclaimable > zones in order to prevent massive overreclaim with many cgroups. > > The latter patch effectively neutered the behavior completely for all > but extreme memory pressure. But in those situations we might as well > drop the reclaimers to lower priority levels. Remove the check. > > Signed-off-by: Johannes Weiner > --- > mm/vmscan.c | 19 +++++-------------- > 1 file changed, 5 insertions(+), 14 deletions(-) > Acked-by: Hillf Danton