From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261738AbULGJrC (ORCPT ); Tue, 7 Dec 2004 04:47:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261721AbULGJrC (ORCPT ); Tue, 7 Dec 2004 04:47:02 -0500 Received: from ns1.enidan.ch ([217.8.216.11]:33005 "EHLO mail.local.net") by vger.kernel.org with ESMTP id S261738AbULGJqr convert rfc822-to-8bit (ORCPT ); Tue, 7 Dec 2004 04:46:47 -0500 From: Per Jessen To: linux-kernel@vger.kernel.org Subject: Re: 2.4.28 - kswapd excessive cpu usage under heavy IO Date: Tue, 7 Dec 2004 10:14:27 +0100 User-Agent: KMail/1.5.4 Organization: n/a MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200412071014.27925.per@computer.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Marcelo Tosatti wrote: > What is your workload? Except the massive amount of inode's/dentries in your > system do you have anonymous memory hungry applications running? Nope, workload is typically 6-7, with probably named being the most memory-hungry. > If you do have a significant amount of anonymous pages on your system you > might want to try 2.4.29-pre1 which contains a VM change which should decrease > their impact on the VM page freeing efforts (including kswapd CPU usage). > > Since you have massive amount of inodes/dentries you might want to tweak > /proc/sys/vm/vm_vfs_scan_ratio (increase from 6 to 10 and so on...) OK, will try that. >>A find in a directory containing perhaps 6-700,000 files makes the box almost >> grind to a halt.  In 12days uptime, kswap has used 590:43.82, and during the >> find-exercise usually runs with 90-100% util. > > Can you boot with profile=2 and use readprofile tool to read the functions > which are using most CPU time with > > readprofile | sort -nr +2 | head -20 > Do that on a 2.4.28 and 2.4.29-pre1 kernels. Will be difficult - I'll keep this in mind, but a reboot is not possible at the moment. Many thanks for getting back to me - much appreciated! -- Per Jessen, Zurich http://www.spamcek.com - let your spam stop here.