From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757349AbcBWEoq (ORCPT ); Mon, 22 Feb 2016 23:44:46 -0500 Received: from mga01.intel.com ([192.55.52.88]:42167 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757107AbcBWEop (ORCPT ); Mon, 22 Feb 2016 23:44:45 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,488,1449561600"; d="scan'208";a="892290973" Subject: Re: [PATCH v3 10/11] KVM: MMU: clear write-flooding on the fast path of tracked page To: Paolo Bonzini References: <1455449503-20993-1-git-send-email-guangrong.xiao@linux.intel.com> <1455449503-20993-11-git-send-email-guangrong.xiao@linux.intel.com> <56C7029F.8010106@redhat.com> Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kai.huang@linux.intel.com, jike.song@intel.com From: Xiao Guangrong Message-ID: <56CBE1C9.7070204@linux.intel.com> Date: Tue, 23 Feb 2016 12:36:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <56C7029F.8010106@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/2016 07:55 PM, Paolo Bonzini wrote: > > > On 14/02/2016 12:31, Xiao Guangrong wrote: >> If the page fault is caused by write access on write tracked page, the >> real shadow page walking is skipped, we lost the chance to clear write >> flooding for the page structure current vcpu is using >> >> Fix it by locklessly waking shadow page table to clear write flooding >> on the shadow page structure out of mmu-lock. So that we change the >> count to atomic_t > > Should this be moved earlier in the series, so that the issue never > surfaces? Okay, i will move it to the place that is behind: [PATCH v3 06/11] KVM: MMU: let page fault handler be aware tracked page