Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754174AbZGFSyD (ORCPT ); Mon, 6 Jul 2009 14:54:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753535AbZGFSxw (ORCPT ); Mon, 6 Jul 2009 14:53:52 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:33908 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753337AbZGFSxw (ORCPT ); Mon, 6 Jul 2009 14:53:52 -0400 Date: Mon, 6 Jul 2009 12:53:53 -0600 From: Matthew Wilcox To: "Ma, Chinang" Cc: Rick Jones , Herbert Xu , Jeff Garzik , "andi@firstfloor.org" , "arjan@infradead.org" , "jens.axboe@oracle.com" , "linux-kernel@vger.kernel.org" , "Styner, Douglas W" , "Prickett, Terry O" , "Wilcox, Matthew R" , "netdev@vger.kernel.org" , "Brandeburg, Jesse" Subject: Re: >10% performance degradation since 2.6.18 Message-ID: <20090706185353.GY5480@parisc-linux.org> References: <20090705040137.GA7747@gondor.apana.org.au> <4A522D9A.1090006@hp.com> <20090706174203.GV5480@parisc-linux.org> <20090706180530.GX5480@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1230 Lines: 22 On Mon, Jul 06, 2009 at 11:48:47AM -0700, Ma, Chinang wrote: > On the distributing interrupt load subject. Can we do the same thing with the IOC interrupts. We have 4 LSI 3801, The number of i/o interrupt is huge on 4 of the cpus. Is there a way to divide the IOC irq number so we can spread out the i/o interrupt to more cpu? I think the LSI 3801 only has one interrupt per ioc, but they could perhaps be better spread-out. Right now, they're delivering interrupts to CPUs 2, 3, 4 and 5. Possibly spreading them out to CPUs 2, 6, 10 and 14 would help. Or maybe it would hurt ... (nb: the ioc interrupts are similarly tied to CPUs 2, 3, 4 and 5 with 2.6.18, so this isn't a likely cause of/solution to the regression, it may just be a path to better numbers). -- 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." -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/