From owner-freebsd-stable@FreeBSD.ORG Tue Jan 15 02:20:37 2008 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 58F9D16A417; Tue, 15 Jan 2008 02:20:37 +0000 (UTC) (envelope-from tom.hurst@clara.net) Received: from spork.qfe3.net (spork.qfe3.net [212.13.207.101]) by mx1.freebsd.org (Postfix) with ESMTP id 0F6B113C458; Tue, 15 Jan 2008 02:20:36 +0000 (UTC) (envelope-from tom.hurst@clara.net) Received: from [81.104.123.28] (helo=voi.aagh.net) by spork.qfe3.net with esmtp (Exim 4.66 (FreeBSD)) (envelope-from ) id 1JEb92-0005BV-OQ; Tue, 15 Jan 2008 02:03:16 +0000 Received: from freaky by voi.aagh.net with local (Exim 4.68 (FreeBSD)) (envelope-from ) id 1JEb92-000F39-G6; Tue, 15 Jan 2008 02:03:16 +0000 Date: Tue, 15 Jan 2008 02:03:16 +0000 From: Thomas Hurst To: John Baldwin Message-ID: <20080115020316.GA47831@voi.aagh.net> Mail-Followup-To: John Baldwin , freebsd-stable@freebsd.org, Peter Jeremy , Kris Kennaway References: <20071203054207.GA1153@aleph.niw.com.au> <4787AAF4.1020905@FreeBSD.org> <20080112033147.GX60060@server.vk2pj.dyndns.org> <200801120005.38972.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200801120005.38972.jhb@freebsd.org> Organization: Not much. User-Agent: Mutt/1.5.17 (2007-11-01) Sender: Thomas Hurst Cc: Peter Jeremy , Kris Kennaway , freebsd-stable@freebsd.org Subject: Re: Swapping caused by very large (regular) file size 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: Tue, 15 Jan 2008 02:20:37 -0000 * John Baldwin (jhb@freebsd.org) wrote: > We have noticed an issue at work but only on faster controllers (e.g. > certain mfi(4) drive configurations) when doing I/O to a single file > like the dd command mentioned causes the buffer cache to fill up. The > problem being that we can't lock the vm object to recycle pages when > we hit the limit that is supposed to prevent this because all the > pages in the cache are for the file (vm object) we are working on. > Stephan (ups@) says this is fixed in 7. Excellent. I've been seeing this behavior for a long time, mostly on backup runs (RAID-1 amr SATA -> 1 disk Marvell ata). It's pretty odd seeing a system with 8G of memory, 60% of which is just cache, swap out half a dozen things for no apparant reason. And to think, people on FreeNode ##freebsd just insisted I had a misconfigured system ;) My other IO related issue with 6 is IO to independent amr arrays blocking each other; e.g. daily run's find over amrd0 will invariably cause reads from amrd1 and amrd2 to freeze for seconds at a time (pr 114438). I'll be very interested to see if 7 fixes that. -- Thomas 'Freaky' Hurst http://hur.st/