From owner-freebsd-stable@FreeBSD.ORG Mon Feb 8 16:13:40 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AD7BE106566B for ; Mon, 8 Feb 2010 16:13:40 +0000 (UTC) (envelope-from mad@madpilot.net) Received: from megatron.madpilot.net (megatron.madpilot.net [88.149.173.206]) by mx1.freebsd.org (Postfix) with ESMTP id 3CDA28FC25 for ; Mon, 8 Feb 2010 16:13:39 +0000 (UTC) Received: from megatron.madpilot.net (localhost [127.0.0.1]) by megatron.madpilot.net (Postfix) with ESMTP id 3E1E91B1E; Mon, 8 Feb 2010 17:13:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=madpilot.net; h= user-agent:in-reply-to:content-disposition:content-type :content-type:mime-version:references:message-id:subject:subject :from:from:date:date:received:received; s=mail; t=1265645616; x= 1267460016; bh=ssXdwTZcduB+yNJyEMC0tXrzvW9bNpexbvLpnas9SAg=; b=C XDzatKhyDj74VrfH7Fj0Jp39igCrM2ZEW5o+aenlI3Xp5I+T3x/L6XJH+2IVytML Pc3CpCQlZJUQyqNsMYGxPjn6c2OfxJEc76nMKxK2CpKtTShoe7ZENugtMLPxbw9H QmGkpu82LRk3zOyzmjdBBYg0k4ZIEfJz6ywxRFH0lg= X-Virus-Scanned: amavisd-new at madpilot.net Received: from megatron.madpilot.net ([127.0.0.1]) by megatron.madpilot.net (megatron.madpilot.net [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id rDs0ns1Uw-9n; Mon, 8 Feb 2010 17:13:36 +0100 (CET) Received: by megatron.madpilot.net (Postfix, from userid 1000) id 8E9FD1B17; Mon, 8 Feb 2010 17:13:36 +0100 (CET) Date: Mon, 8 Feb 2010 17:13:36 +0100 From: Guido Falsi To: Ivan Voras Message-ID: <20100208161336.GA43063@megatron.madpilot.net> References: <20100208143329.GA12057@megatron.madpilot.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: FreeBSD 8.0-STABLE User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-stable@freebsd.org Subject: Re: ATA_CAM + ZFS gives short 1-2 seconds system freeze on disk load X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Feb 2010 16:13:40 -0000 On Mon, Feb 08, 2010 at 03:41:14PM +0100, Ivan Voras wrote: > On 02/08/10 15:33, Guido Falsi wrote: > > >It looks like it freezes the system for the second or two it takes > >to flush buffers to disk when there are big outputs. This happens > >when decompressiong big distfiles, mainly. The openoffice port > >triggers this almost continuosly every few seconds during compilation. > >I've also seen this when working with big files(for example graphic > >images in uncompressed formats). > > > >It gets very annoying and I don't remember this happening before > >activating the ATA_CAM flag. There was some slowdown with big disk > >access, but not a total freeze. > > I think ZFS does this all the time, i.e. regardless of underlying > device drivers. Can you test your theory by going to an older kernel > and keeping *everything* else the same? I have made the test and in fact I see the same freezes without ATA_CAM and the legacy ata system. Maybe my idea was due to selective memory :) The other problem at boot still exists with ATA_CAM and does not without it. I'll create a new thread about this as suggested by Jeremy Chadwick. -- Guido Falsi