From owner-freebsd-fs@FreeBSD.ORG Mon Nov 1 10:39:48 2010 Return-Path: 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 299AD106564A; Mon, 1 Nov 2010 10:39:48 +0000 (UTC) (envelope-from wjw@digiware.nl) Received: from mail.digiware.nl (mail.ip6.digiware.nl [IPv6:2001:4cb8:1:106::2]) by mx1.freebsd.org (Postfix) with ESMTP id AE9848FC08; Mon, 1 Nov 2010 10:39:47 +0000 (UTC) Received: from localhost (localhost.digiware.nl [127.0.0.1]) by mail.digiware.nl (Postfix) with ESMTP id B9613153434; Mon, 1 Nov 2010 11:39:45 +0100 (CET) X-Virus-Scanned: amavisd-new at digiware.nl Received: from mail.digiware.nl ([127.0.0.1]) by localhost (rack1.digiware.nl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sr-RcVERgydU; Mon, 1 Nov 2010 11:39:43 +0100 (CET) Received: from [127.0.0.1] (opteron [192.168.10.67]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mail.digiware.nl (Postfix) with ESMTPSA id 91FBC153433; Mon, 1 Nov 2010 11:39:43 +0100 (CET) Message-ID: <4CCE98ED.6010002@digiware.nl> Date: Mon, 01 Nov 2010 11:39:41 +0100 From: Willem Jan Withagen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.12) Gecko/20101027 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Andriy Gapon References: <4CCAF0EB.4080001@icyb.net.ua> <20101029175105.GB18613@two.kliksys.ru> <4CCBD443.7010305@icyb.net.ua><4CCBD46E.9030200@icyb.net.ua> <4CCBD661.3000204@freebsd.org><4CCBEAF6.2030408@freebsd.org> <20101030101254.GB79691@two.kliksys.ru> <4CCBF45C.4080208@icyb.net.ua> <20101030112520.GD79691@two.kliksys.ru> <4CCC2F2A.7020809@icyb.net.ua><20101030190120.GA80301@two.kliksys.ru> <4CCD0804.8010703@icyb.net.ua> <4CCE6CAD.30304@icyb.net.ua> In-Reply-To: <4CCE6CAD.30304@icyb.net.ua> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org Subject: Re: 8.1-STABLE: zfs and sendfile: problem still exists X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Nov 2010 10:39:48 -0000 On 2010-11-01 8:30, Andriy Gapon wrote: > First and foremost, the double-caching issue for ZFS+sendfile on FreeBSD is > still there and no resolution for this issue is on horizon. So, you have to > account for the fact that twice as much memory is needed for this use-case. > Whether you plan your system, or configure it, or tune it. > > Second, with recent head and stable/8 ARC should not be the primary victim of > memory pressure; ARC reclaim thread and the page daemon should cooperate in > freeing/recycling memory. > > Nothing much to add. Although this discussion started due to issues with serving files thru web-typish services, there are more apps that use sendfile. For one, I noticed that I had once enabled sendfile in my Samba config. As per this discussion I saw little advantage in keeping it that way...... But I'm open for other suggestions. --WjW