From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 7B2B26B0038 for ; Mon, 2 Nov 2015 11:52:24 -0500 (EST) Received: by pacfv9 with SMTP id fv9so160036728pac.3 for ; Mon, 02 Nov 2015 08:52:24 -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 fb8si36079503pab.221.2015.11.02.08.52.23 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 02 Nov 2015 08:52:23 -0800 (PST) Subject: Re: [patch 3/3] vmstat: Create our own workqueue From: Tetsuo Handa References: <20151029022447.GB27115@mtj.duckdns.org> <20151029030822.GD27115@mtj.duckdns.org> <201510311143.BIH87000.tOSVFHOFJMLFOQ@I-love.SAKURA.ne.jp> In-Reply-To: Message-Id: <201511030152.JGF95845.SHVLOMtOJFFOFQ@I-love.SAKURA.ne.jp> Date: Tue, 3 Nov 2015 01:52:13 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: cl@linux.com Cc: htejun@gmail.com, akpm@linux-foundation.org, mhocko@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, hannes@cmpxchg.org, mgorman@suse.de Christoph Lameter wrote: > On Sat, 31 Oct 2015, Tetsuo Handa wrote: > > > Then, you need to update below description (or drop it) because > > patch 3/3 alone will not guarantee that the counters are up to date. > > The vmstat system does not guarantee that the counters are up to date > always. The whole point is the deferral of updates for performance > reasons. They are updated *at some point* within stat_interval. That needs > to happen and that is what this patchset is fixing. > I'm still unclear. I think that the result of this patchset is The counters are never updated even after stat_interval if some workqueue item is doing a __GFP_WAIT memory allocation. but the patch description sounds as if The counters will be updated even if some workqueue item is doing a __GFP_WAIT memory allocation. which denies the actual result I tested with this patchset applied. -- 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