From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: rq_affinity doesn't seem to work? Date: Wed, 13 Jul 2011 11:10:11 -0600 Message-ID: <20110713171011.GA11864@parisc-linux.org> References: <4E1CAEEB.8050506@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:56945 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932175Ab1GMRKN (ORCPT ); Wed, 13 Jul 2011 13:10:13 -0400 Content-Disposition: inline In-Reply-To: <4E1CAEEB.8050506@kernel.dk> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jens Axboe Cc: "Jiang, Dave" , "Williams, Dan J" , "Foong, Annie" , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Nadolski, Edmund" , "Skirvin, Jeffrey D" On Tue, Jul 12, 2011 at 10:30:35PM +0200, Jens Axboe wrote: > It's probably the grouping, we need to do something about that. Does the > below patch make it behave as you expect? "something", absolutely. But there is benefit from doing some aggregation (we tried disabling it entirely with the "well-known OLTP benchmark" and performance went down). Ideally we'd do something like "if the softirq is taking up more than 10% of a core, split the grouping". Do we have enough stats to do that kind of monitoring? -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."