From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id 179AF6B0253 for ; Fri, 29 Jan 2016 10:17:58 -0500 (EST) Received: by mail-wm0-f49.google.com with SMTP id l66so58832786wml.0 for ; Fri, 29 Jan 2016 07:17:58 -0800 (PST) Received: from mail-wm0-f67.google.com (mail-wm0-f67.google.com. [74.125.82.67]) by mx.google.com with ESMTPS id pd7si22756577wjb.47.2016.01.29.07.17.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 Jan 2016 07:17:56 -0800 (PST) Received: by mail-wm0-f67.google.com with SMTP id r129so10456070wmr.0 for ; Fri, 29 Jan 2016 07:17:56 -0800 (PST) Date: Fri, 29 Jan 2016 16:17:55 +0100 From: Michal Hocko Subject: Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Message-ID: <20160129151755.GE32174@dhcp22.suse.cz> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201601291935.BGJ95389.VOLMFOOHFStQFJ@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa 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 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? -- 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