From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761166AbYHVBGS (ORCPT ); Thu, 21 Aug 2008 21:06:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755074AbYHVBGD (ORCPT ); Thu, 21 Aug 2008 21:06:03 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:47409 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753517AbYHVBGA (ORCPT ); Thu, 21 Aug 2008 21:06:00 -0400 Date: Fri, 22 Aug 2008 10:05:45 +0900 From: KOSAKI Motohiro To: "KOSAKI Motohiro" Subject: Re: [RFC][PATCH 1/2] Show quicklist at meminfo Cc: kosaki.motohiro@jp.fujitsu.com, "Andrew Morton" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cl@linux-foundation.org, tokunaga.keiich@jp.fujitsu.com In-Reply-To: <2f11576a0808210036icd9b61eue58049f15381bcc8@mail.gmail.com> References: <20080820113559.f559a411.akpm@linux-foundation.org> <2f11576a0808210036icd9b61eue58049f15381bcc8@mail.gmail.com> Message-Id: <20080822100049.F562.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > quicklist_total_size() is racy against cpu hotplug. That's OK for > > /proc/meminfo purposes (occasional transient inaccuracy?), but will it > > crash? Not in the current implementation of per_cpu() afaict, but it > > might crash if we ever teach cpu hotunplug to free up the percpu > > resources. > > First, Quicklist doesn't concern to cpu hotplug at all. > it is another quicklist problem. > > Next, I think it doesn't cause crash. but I haven't any test. > So, I'll test cpu hotplug/unplug testing today. > > I'll report result tommorow. OK. I ran cpu hotplug/unplug coutinuous workload over 12H. then, system crash doesn't happend. So, I believe my patch is cpu unplug safe. test method -------------------------------------------------------------- 1. open 7 terminal and following script run on each console. CPU=cpuXXX; while true; do echo 0 > /sys/devices/system/cpu/$CPU/online; echo 1 > /sys/devi ces/system/cpu/$CPU/online;done 2. open another console, following command run. watch -n 1 cat /proc/meminfo