From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756138Ab2DQOri (ORCPT ); Tue, 17 Apr 2012 10:47:38 -0400 Received: from mail-pz0-f52.google.com ([209.85.210.52]:65084 "EHLO mail-pz0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753123Ab2DQOrg (ORCPT ); Tue, 17 Apr 2012 10:47:36 -0400 Date: Tue, 17 Apr 2012 23:47:31 +0900 From: Takuya Yoshikawa To: Xiao Guangrong Cc: Avi Kivity , Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH v2 07/16] KVM: MMU: introduce for_each_pte_list_spte Message-Id: <20120417234731.a19f270d5701b11ce95d13d4@gmail.com> In-Reply-To: <4F8B93B9.2030801@linux.vnet.ibm.com> References: <4F87FA69.5060106@linux.vnet.ibm.com> <4F87FC19.8080404@linux.vnet.ibm.com> <20120414114422.e3fe6e2abbfdcce61e6f69c8@gmail.com> <4F8B93B9.2030801@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.2.0beta3 (GTK+ 2.24.6; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Apr 2012 11:36:25 +0800 Xiao Guangrong wrote: > I tested it with kernbench, no regression is found. Because kernbench is not at all good test for this. > It is not a problem since the iter and spte should be in the cache. I have checked dirty-log-perf myself with this patch [01-07]. GET_DIRTY_LOG for 1GB dirty pages has become more than 15% slower. This is not a pure cleanup and introduces significant regression to rmap handling. This is the reason why I asked to remove "cleanup patches" from this patch series. Had it been really trivial cleanup, I would not have asked that. Note: if you had checked the worst case latency with this patch series, you should have noticed this regression by yourself. Auto-test and kernbench are not enough to see the effect of this work. Thanks, Takuya