From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH 1/2] KVM: mmu_notifier: Flush TLBs before releasing mmu_lock
Date: Fri, 10 Feb 2012 15:52:49 +0800
Message-ID: <4F34CCD1.6050103@linux.vnet.ibm.com>
References: <20120210152831.6ac3ac87.yoshikawa.takuya@oss.ntt.co.jp>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Cc: avi@redhat.com, mtosatti@redhat.com, kvm@vger.kernel.org,
	aarcange@redhat.com
To: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Return-path: <kvm-owner@vger.kernel.org>
Received: from e23smtp04.au.ibm.com ([202.81.31.146]:58756 "EHLO
	e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753546Ab2BJHw5 (ORCPT <rfc822;kvm@vger.kernel.org>);
	Fri, 10 Feb 2012 02:52:57 -0500
Received: from /spool/local
	by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted
	for <kvm@vger.kernel.org> from <xiaoguangrong@linux.vnet.ibm.com>;
	Fri, 10 Feb 2012 07:37:29 +1000
Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97])
	by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q1A7lnvP2941088
	for <kvm@vger.kernel.org>; Fri, 10 Feb 2012 18:47:50 +1100
Received: from d23av03.au.ibm.com (loopback [127.0.0.1])
	by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q1A7qpaG031851
	for <kvm@vger.kernel.org>; Fri, 10 Feb 2012 18:52:51 +1100
In-Reply-To: <20120210152831.6ac3ac87.yoshikawa.takuya@oss.ntt.co.jp>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 02/10/2012 02:28 PM, Takuya Yoshikawa wrote:

> Other threads may process the same page in that small window and skip
> TLB flush and then return before these functions do flush.
> 


It is possible that flush tlb in mmu lock only when writeable
spte is invalided? Sometimes, kvm_flush_remote_tlbs need
long time to wait.