From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 17 Jun 2008 00:42:17 -0700 (PDT) Received: from cuda.sgi.com ([192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m5H7gFee029377 for ; Tue, 17 Jun 2008 00:42:16 -0700 Received: from ipmail01.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id EFB4917D846B for ; Tue, 17 Jun 2008 00:43:11 -0700 (PDT) Received: from ipmail01.adl6.internode.on.net (ipmail01.adl6.internode.on.net [203.16.214.146]) by cuda.sgi.com with ESMTP id JxDgt09AUHLegEWZ for ; Tue, 17 Jun 2008 00:43:11 -0700 (PDT) Date: Tue, 17 Jun 2008 17:41:58 +1000 From: Dave Chinner Subject: Re: XFS mkfs/mount options Message-ID: <20080617074158.GQ3700@disturbed> References: <881489.19090.qm@web34506.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <881489.19090.qm@web34506.mail.mud.yahoo.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Mark Cc: xfs@oss.sgi.com On Tue, Jun 17, 2008 at 12:33:57AM -0700, Mark wrote: > I have been doing some experiments with XFS on my "hot new desktop > system," and I have turned up an interesting bit of info. (Note: > My system is an AMD64 X2 2.5GHz running Linux.) > > When I mount an XFS volume (thus loading the xfs kernel module), > the kernel spawns two CPU-bound threads for "xfslogd" and > "xfsdatad". However, it appears that only one of each of these > kernel processes is getting any load, as indicated by "ps ax": > > 3700 ? S< 0:00 [xfslogd/0] > 3701 ? S< 0:19 [xfslogd/1] > 3702 ? S< 0:00 [xfsdatad/0] > 3703 ? D< 0:05 [xfsdatad/1] > > For each of these kernel threads, only those on CPU #2 are actually pulling notable load. Why is this? Because your disk interrupts are delivered to that CPU only. Cheers, Dave. -- Dave Chinner david@fromorbit.com