From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: no need to test bit before setting dirty bit these days Date: Fri, 23 Apr 2010 13:31:49 +0300 Message-ID: <4BD17715.1020406@redhat.com> References: <20100423174835.0c231699.yoshikawa.takuya@oss.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: mtosatti@redhat.com, kvm@vger.kernel.org To: Takuya Yoshikawa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:11895 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754698Ab0DWKby (ORCPT ); Fri, 23 Apr 2010 06:31:54 -0400 In-Reply-To: <20100423174835.0c231699.yoshikawa.takuya@oss.ntt.co.jp> Sender: kvm-owner@vger.kernel.org List-ID: On 04/23/2010 11:48 AM, Takuya Yoshikawa wrote: > As Avi pointed out, testing bit part in mark_page_dirty() was important > in the days of shadow paging, but currently EPT and NPT has already become > common and the chance of faulting a page more that once per iteration is > small. So let's remove the test bit to avoid extra access. > Applied, thanks. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.