From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f53.google.com (mail-oi0-f53.google.com [209.85.218.53]) by kanga.kvack.org (Postfix) with ESMTP id D3A9E6B0255 for ; Fri, 29 Jan 2016 16:30:41 -0500 (EST) Received: by mail-oi0-f53.google.com with SMTP id k206so55757757oia.1 for ; Fri, 29 Jan 2016 13:30:41 -0800 (PST) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id nz3si14005536obc.61.2016.01.29.13.30.40 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 29 Jan 2016 13:30:40 -0800 (PST) Subject: Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise From: Tetsuo Handa References: <1450203586-10959-1-git-send-email-mhocko@kernel.org> <1454015979-9985-1-git-send-email-mhocko@kernel.org> <201601291935.BGJ95389.VOLMFOOHFStQFJ@I-love.SAKURA.ne.jp> <20160129151755.GE32174@dhcp22.suse.cz> In-Reply-To: <20160129151755.GE32174@dhcp22.suse.cz> Message-Id: <201601300630.HBC43269.JFHFQFOVOLOMtS@I-love.SAKURA.ne.jp> Date: Sat, 30 Jan 2016 06:30:15 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, hannes@cmpxchg.org, mgorman@suse.de, rientjes@google.com, hillf.zj@alibaba-inc.com, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Michal Hocko wrote: > On Fri 29-01-16 19:35:18, Tetsuo Handa wrote: > > Michal Hocko wrote: > > > From: Michal Hocko > > > > > > zone_reclaimable_pages is used in should_reclaim_retry which uses it to > > > calculate the target for the watermark check. This means that precise > > > numbers are important for the correct decision. zone_reclaimable_pages > > > uses zone_page_state which can contain stale data with per-cpu diffs > > > not synced yet (the last vmstat_update might have run 1s in the past). > > > > > > Use zone_page_state_snapshot in zone_reclaimable_pages instead. None > > > of the current callers is in a hot path where getting the precise value > > > (which involves per-cpu iteration) would cause an unreasonable overhead. > > > > > > Suggested-by: David Rientjes > > > Signed-off-by: Michal Hocko > > > --- > > > mm/vmscan.c | 14 +++++++------- > > > 1 file changed, 7 insertions(+), 7 deletions(-) > > > > > > > I didn't know http://lkml.kernel.org/r/20151021130323.GC8805@dhcp22.suse.cz > > was forgotten. Anyway, > > OK, that explains why this sounded so familiar. Sorry I comepletely > forgot about it. > > > Acked-by: Tetsuo Handa > > Can I change it to your Signed-off-by? No problem. > > -- > 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