From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 7/9] Add VMRUN handler v3 Date: Sat, 27 Sep 2008 15:59:03 +0300 Message-ID: <48DE2E17.4040602@redhat.com> References: <1221658886-14109-3-git-send-email-agraf@suse.de> <1221658886-14109-4-git-send-email-agraf@suse.de> <1221658886-14109-5-git-send-email-agraf@suse.de> <1221658886-14109-6-git-send-email-agraf@suse.de> <1221658886-14109-7-git-send-email-agraf@suse.de> <1221658886-14109-8-git-send-email-agraf@suse.de> <20080919155926.GR24392@amd.com> <319028FA-B559-44C0-BA7C-0A1AD96CDA52@suse.de> <20080925173746.GB27928@amd.com> <60483CCB-2721-4936-A041-7296F900CCE1@suse.de> <20080925212242.GM27426@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Alexander Graf , Joerg Roedel , "kvm@vger.kernel.org" , "anthony@codemonkey.ws" To: "joro@8bytes.org" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:55870 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752458AbYI0M7F (ORCPT ); Sat, 27 Sep 2008 08:59:05 -0400 In-Reply-To: <20080925212242.GM27426@8bytes.org> Sender: kvm-owner@vger.kernel.org List-ID: joro@8bytes.org wrote: > Copying data in memory is always expensive because the accesses may miss > in the caches and data must be fetched from memory. As far as I know > this can be around 150 cycles per cache line. > When the copy is sequential, the processor will prefetch the data ahead of time, so you don't get the full hit. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.