From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NfEtL-000800-Sk
	for qemu-devel@nongnu.org; Wed, 10 Feb 2010 10:54:15 -0500
Received: from [199.232.76.173] (port=51307 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NfEtL-0007zs-Ak
	for qemu-devel@nongnu.org; Wed, 10 Feb 2010 10:54:15 -0500
Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim
	4.60) (envelope-from <anthony@codemonkey.ws>) id 1NfEtH-0006IP-3g
	for qemu-devel@nongnu.org; Wed, 10 Feb 2010 10:54:14 -0500
Received: from mail-iw0-f194.google.com ([209.85.223.194]:34154)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <anthony@codemonkey.ws>) id 1NfEtG-0006I9-Es
	for qemu-devel@nongnu.org; Wed, 10 Feb 2010 10:54:10 -0500
Received: by iwn32 with SMTP id 32so238340iwn.14
	for <qemu-devel@nongnu.org>; Wed, 10 Feb 2010 07:54:09 -0800 (PST)
Message-ID: <4B72D69D.7050005@codemonkey.ws>
Date: Wed, 10 Feb 2010 09:54:05 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
References: <4B728FF9.6010707@lab.ntt.co.jp> <4B72B28E.6010801@redhat.com>
In-Reply-To: <4B72B28E.6010801@redhat.com>
Content-Type: text/plain; charset=ISO-2022-JP
Content-Transfer-Encoding: 7bit
Subject: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the
	dirty-bitmap-traveling
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Avi Kivity <avi@redhat.com>
Cc: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>, mtosatti@redhat.com, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, Anthony Liguori <aliguori@us.ibm.com>

On 02/10/2010 07:20 AM, Avi Kivity wrote:
> On 02/10/2010 12:52 PM, OHMURA Kei wrote:
>   
>> dirty-bitmap-traveling is carried out by byte size in qemu-kvm.c.
>> But We think that dirty-bitmap-traveling by long size is faster than by byte
>> size especially when most of memory is not dirty.
>>
>> --- a/bswap.h
>> +++ b/bswap.h
>> @@ -209,7 +209,6 @@ static inline void cpu_to_be32wu(uint32_t *p, uint32_t v)
>>  #define cpu_to_32wu cpu_to_le32wu
>>  #endif
>>  
>> -#undef le_bswap
>>  #undef be_bswap
>>  #undef le_bswaps
>>   
>>     
>
> Anthony, is it okay to export le_bswap this way, or will you want
> leul_to_cpu()?
>   

kvm_get_dirty_pages_log_range() is kvm-specific code. We're guaranteed
that when we're using kvm, target byte order == host byte order.

So is it really necessary to use a byte swapping function at all?

Regards,

Anthony Liguori