From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753893AbZLRONy (ORCPT ); Fri, 18 Dec 2009 09:13:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753827AbZLRONx (ORCPT ); Fri, 18 Dec 2009 09:13:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9245 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753820AbZLRONw (ORCPT ); Fri, 18 Dec 2009 09:13:52 -0500 Message-ID: <4B2B8E16.9070504@redhat.com> Date: Fri, 18 Dec 2009 16:13:42 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091203 Fedora/3.0-3.13.rc2.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Rik van Riel CC: lwoodman@redhat.com, akpm@linux-foundation.org, KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org, minchan.kim@gmail.com Subject: Re: [PATCH v2] vmscan: limit concurrent reclaimers in shrink_zone References: <20091211164651.036f5340@annuminas.surriel.com> <4B2B85C3.5040409@redhat.com> <4B2B8DC6.7010506@redhat.com> In-Reply-To: <4B2B8DC6.7010506@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/2009 04:12 PM, Rik van Riel wrote: > On 12/18/2009 08:38 AM, Avi Kivity wrote: > >>> + /* Number of processes running page reclaim code on this zone. */ >>> + atomic_t concurrent_reclaimers; >>> + wait_queue_head_t reclaim_wait; >>> + >> >> Counting semaphore? > > I don't see a safe way to adjust a counting semaphore > through /proc/sys. True. Maybe it's worthwhile to add such a way if this pattern has more uses. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.