From mboxrd@z Thu Jan  1 00:00:00 1970
From: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Subject: Re: [PATCH 3/4] KVM: Count the number of dirty pages for dirty logging
Date: Tue, 20 Dec 2011 13:29:35 +0900
Message-ID: <4EF00F2F.6080305@oss.ntt.co.jp>
References: <20111114182041.43570cdf.yoshikawa.takuya@oss.ntt.co.jp> <20111114182334.f57fbeae.yoshikawa.takuya@oss.ntt.co.jp> <4EC0E85F.80004@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: mtosatti@redhat.com, kvm@vger.kernel.org,
	takuya.yoshikawa@gmail.com
To: Avi Kivity <avi@redhat.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from serv2.oss.ntt.co.jp ([222.151.198.100]:50465 "EHLO
	serv2.oss.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751415Ab1LTE2h (ORCPT <rfc822;kvm@vger.kernel.org>);
	Mon, 19 Dec 2011 23:28:37 -0500
In-Reply-To: <4EC0E85F.80004@redhat.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

(2011/11/14 19:07), Avi Kivity wrote:
>> @@ -1491,7 +1492,8 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
>>   	if (memslot&&  memslot->dirty_bitmap) {
>>   		unsigned long rel_gfn = gfn - memslot->base_gfn;
>>
>> -		__set_bit_le(rel_gfn, memslot->dirty_bitmap);
>> +		if (!__test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap))
>> +			memslot->nr_dirty_pages++;
>>   	}
>>   }
>>

[snip]

> btw mark_page_dirty() itself seems to assume mmu_lock protection that
> doesn't exist.  Marcelo?
>

I want to hear the answer for this question.

Though I myself is reading the code, I cannot understand it thoroughly yet.
I wish if there were mmu_lock entry in locking.txt ...

	Takuya