From owner-freebsd-fs@FreeBSD.ORG  Wed Sep  8 08:53:26 2010
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 0D3EE10656E0;
	Wed,  8 Sep 2010 08:53:26 +0000 (UTC) (envelope-from avg@freebsd.org)
Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140])
	by mx1.freebsd.org (Postfix) with ESMTP id 037D18FC13;
	Wed,  8 Sep 2010 08:53:24 +0000 (UTC)
Received: from porto.topspin.kiev.ua (porto-e.starpoint.kiev.ua
	[212.40.38.100])
	by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id LAA08721;
	Wed, 08 Sep 2010 11:53:21 +0300 (EEST)
	(envelope-from avg@freebsd.org)
Received: from localhost.topspin.kiev.ua ([127.0.0.1])
	by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD))
	id 1OtGPA-0000WR-Ug; Wed, 08 Sep 2010 11:53:20 +0300
Message-ID: <4C874F00.3050605@freebsd.org>
Date: Wed, 08 Sep 2010 11:53:20 +0300
From: Andriy Gapon <avg@freebsd.org>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US;
	rv:1.9.2.8) Gecko/20100822 Lightning/1.0b2 Thunderbird/3.1.2
MIME-Version: 1.0
To: Kostik Belousov <kostikbel@gmail.com>
References: <5DB6E7C798E44D33A05673F4B773405E@multiplay.co.uk>
	<AANLkTikNhsj5myhQCoPaNytUbpHtox1vg9AZm1N-OcMO@mail.gmail.com>
	<4C85E91E.1010602@icyb.net.ua> <4C873914.40404@freebsd.org>
	<20100908084855.GF2465@deviant.kiev.zoral.com.ua>
In-Reply-To: <20100908084855.GF2465@deviant.kiev.zoral.com.ua>
X-Enigmail-Version: 1.1.2
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Cc: freebsd-fs@freebsd.org, Pawel Jakub Dawidek <pjd@freebsd.org>
Subject: Re: zfs very poor performance compared to ufs due to lack of cache?
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 08 Sep 2010 08:53:26 -0000

on 08/09/2010 11:48 Kostik Belousov said the following:
> On Wed, Sep 08, 2010 at 10:19:48AM +0300, Andriy Gapon wrote:
>> on 07/09/2010 10:26 Andriy Gapon said the following:
>>> Interesting.  I briefly looked at the code in mappedread(), zfs_vnops.c, and I
>>> have a VM question.
>>> Shouldn't we mark the corresponding page bits as valid after reading data into
>>> the page?
>>> I specifically speak of the block that starts with the following line:
>>> } else if (m != NULL && uio->uio_segflg == UIO_NOCOPY) {
>>> I am taking mdstart_swap as an example and it does m->valid = VM_PAGE_BITS_ALL.
>>>
>>
>> I've chatted with and conclusion seems to be that vm_page_set_validclean() call
>> should be added at the end of the block.
>>
>> Perhaps, something like this:
>>
>> --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
>> +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
>> @@ -500,6 +500,7 @@ again:
>>  				sched_unpin();
>>  			}
>>  			VM_OBJECT_LOCK(obj);
>> +			vm_page_set_validclean(m, off, bytes);
> Only if error == 0, perhaps ?

Yes, I agree, thanks!

-- 
Andriy Gapon