Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754208AbbKBQwT (ORCPT ); Mon, 2 Nov 2015 11:52:19 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:50571 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752603AbbKBQwP (ORCPT ); Mon, 2 Nov 2015 11:52:15 -0500 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 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> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Tue, 3 Nov 2015 01:52:13 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1135 Lines: 27 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/