From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ViRPS-0005eS-6j for qemu-devel@nongnu.org; Mon, 18 Nov 2013 11:10:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ViRPM-000831-68 for qemu-devel@nongnu.org; Mon, 18 Nov 2013 11:10:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26202) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ViRPL-00082N-UA for qemu-devel@nongnu.org; Mon, 18 Nov 2013 11:10:40 -0500 Message-ID: <528A3BE6.2040202@redhat.com> Date: Mon, 18 Nov 2013 17:10:14 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1382599289-9503-1-git-send-email-pl@kamp.de> <5268E4EF.3090007@redhat.com> <528A0C84.6080809@kamp.de> In-Reply-To: <528A0C84.6080809@kamp.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RESEND][PATCH 1.7] migration: drop MADVISE_DONT_NEED for incoming zero pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven , quintela@redhat.com Cc: haoyu.zhang@huawei.com, qemu-devel@nongnu.org, afaerber@suse.de, xiaoguangrong@linux.vnet.ibm.com Il 18/11/2013 13:48, Peter Lieven ha scritto: > On 24.10.2013 11:14, Paolo Bonzini wrote: >> Il 24/10/2013 08:21, Peter Lieven ha scritto: >>> Additionally we memmap target memory so it is essentially >>> zero initialized (except for e.g. option roms and bios which are loaded >>> into target memory although they shouldn't). >>> >>> It was reported recently that this madvise causes a performance >>> degradation >>> in some situations. As the madvise should only be called rarely and >>> if it's called >>> it is likely on a busy page (it was non-zero and changed to zero >>> during migration) >>> drop it completely. >> Tagging this patch for 1.7. > has this been merged? No. Juan, can you prepare a quick pull request? Paolo