From owner-freebsd-stable@FreeBSD.ORG Sun Sep 16 18:53:15 2007 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 B46E416A41A for ; Sun, 16 Sep 2007 18:53:15 +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 812B313C48D for ; Sun, 16 Sep 2007 18:53:15 +0000 (UTC) (envelope-from tom.hurst@clara.net) Received: from [81.104.144.87] (helo=voi.aagh.net) by spork.qfe3.net with esmtp (Exim 4.66 (FreeBSD)) (envelope-from ) id 1IWzF4-0009L1-6h for freebsd-stable@freebsd.org; Sun, 16 Sep 2007 19:53:14 +0100 Received: from freaky by voi.aagh.net with local (Exim 4.67 (FreeBSD)) (envelope-from ) id 1IWzF3-0002D6-FF for freebsd-stable@freebsd.org; Sun, 16 Sep 2007 19:53:13 +0100 Date: Sun, 16 Sep 2007 19:53:13 +0100 From: Thomas Hurst To: freebsd-stable@freebsd.org Message-ID: <20070916185313.GA7784@voi.aagh.net> Mail-Followup-To: freebsd-stable@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Organization: Not much. User-Agent: Mutt/1.5.16 (2007-06-09) Sender: Thomas Hurst Subject: Dubious VM behavior scanning large files 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: Sun, 16 Sep 2007 18:53:15 -0000 I'm currently verifying a 50GB filesystem dump with sha1 at about 40MB/s. This is resulting in a small but annoying amount of swapping, including my IRC client, text editors, even syslogd. Larger processes like my .5G-each mysqld and squid don't seem to be effected: Mem: 2045M Active, 5025M Inact, 439M Wired, 251M Cache, 214M Buf, 11M Free Swap: 10G Total, 12M Used, 10G Free, 232K Out cat(1), dd(1), par2, all result in the same sort of thing; I have well over over 4GB of memory used for nothing but disk cache, and the VM is somehow deciding it's cheaper to swap out fairly active processes (including syslogd) than it is to free up a few inactive pages. Swap never goes above about 12MB, but pages are in and out fairly often. Do I need to tune the VM to keep more free pages around? This is a dual dual core AMD64 system with 8G of memory, and it's running 6.2-STABLE as of July 4th, and verified just now with -STABLE dated Sep 16. I also again noticed dubious swap metering from top/swapinfo during today's testing: 1169 clamav 1 4 0 67620K 0K accept 2 0:04 0.00% 1301 freaky 1 96 0 24916K 0K select 3 0:00 0.00% Along with a few other processes, and yet: Swap: 10G Total, 8K Used, 10G Free This has been mentioned before, and I don't think anyone was able to explain it. Swap later rose to about 900k, but only after several instances of SpamAssassin were marked as swapped. -- Thomas 'Freaky' Hurst http://hur.st/