From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2 6/8] kvm tools: Add rwlock wrapper Date: Mon, 30 May 2011 17:30:00 +0300 Message-ID: <4DE3A9E8.4010307@redhat.com> References: <20110530095451.GB8461@elte.hu> <20110530201110.f3bf20b5.yoshikawa.takuya@oss.ntt.co.jp> <1306753954.14564.92.camel@lappy> <20110530202646.eff0ea28.yoshikawa.takuya@oss.ntt.co.jp> <4DE381DB.8040804@redhat.com> <20110530114949.GD22324@elte.hu> <1306756681.14564.95.camel@lappy> <20110530122027.GJ22324@elte.hu> <4DE38C50.404@redhat.com> <20110530141058.GA12360@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Sasha Levin , Pekka Enberg , Takuya Yoshikawa , kvm@vger.kernel.org, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com, "Paul E. McKenney" , takuya.yoshikawa@gmail.com To: Ingo Molnar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:59157 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751986Ab1E3OaP (ORCPT ); Mon, 30 May 2011 10:30:15 -0400 In-Reply-To: <20110530141058.GA12360@elte.hu> Sender: kvm-owner@vger.kernel.org List-ID: On 05/30/2011 05:10 PM, Ingo Molnar wrote: > > [...] Windows has a zeroing thread which causes all of RAM to be > > committed shortly after boot, though. > > heh, maybe they read lkml and copied my ancient idea: > > http://people.redhat.com/mingo/clearpage-patches/clearpage-2.3.18-J1 > > An earlier version had a 'zerod' (page zeroing kernel thread). > > This was one of my more stupid ideas btw. > I think that with a dma engine it makes sense. We've got an extra resource, why not utilize it in the background? Some workloads generate a lot of demand for zero pages. I agree that using the cpu to clear memory is not a good idea, it just causes cache pollution. -- error compiling committee.c: too many arguments to function