Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933793AbZKXSAv (ORCPT ); Tue, 24 Nov 2009 13:00:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933771AbZKXSAs (ORCPT ); Tue, 24 Nov 2009 13:00:48 -0500 Received: from mga01.intel.com ([192.55.52.88]:3680 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933769AbZKXSAr (ORCPT ); Tue, 24 Nov 2009 13:00:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.47,280,1257148800"; d="scan'208";a="516968703" Subject: Re: [PATCH v6] x86/apic: limit irq affinity From: Peter P Waskiewicz Jr To: "Eric W. Biederman" Cc: Arjan van de Ven , Thomas Gleixner , Peter Zijlstra , Dimitri Sivanich , Ingo Molnar , "Siddha, Suresh B" , Yinghai Lu , LKML , Jesse Barnes , David Miller , "H. Peter Anvin" In-Reply-To: References: <20091120211139.GB19106@sgi.com> <20091122011457.GA16910@sgi.com> <1259069986.4531.1453.camel@laptop> <20091124065022.6933be1a@infradead.org> Content-Type: text/plain Date: Tue, 24 Nov 2009 10:00:56 -0800 Message-Id: <1259085656.2631.50.camel@ppwaskie-mobl2> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1540 Lines: 42 On Tue, 2009-11-24 at 09:41 -0800, Eric W. Biederman wrote: > Arjan van de Ven writes: > > > On Tue, 24 Nov 2009 14:55:15 +0100 (CET) > >> > Furthermore, the /sysfs topology information should include IRQ > >> > routing data in this case. > >> > >> Hmm, not sure about that. You'd need to scan through all the nodes to > >> find the set of CPUs where an irq can be routed to. I prefer to have > >> the information exposed by the irq enumeration (which is currently in > >> /proc/irq though). > > > > yes please. > > > > one device can have multiple irqs > > one irq can be servicing multiple devices > > > > expressing that in sysfs is a nightmare, while > > sticking it in /proc/irq *where the rest of the info is* is > > much nicer for apps like irqbalance > > Oii. > > I don't think it is bad to export information to applications like irqbalance. > > I think it pretty horrible that one of the standard ways I have heard > to improve performance on 10G nics is to kill irqbalance. > This is something I'm actively trying to fix (see thread "irq: Add node_affinity CPU masks for smarter irqbalance hints"). That patch may not be the final answer, but whatever comes of it will fix the recommendation of "killall irqbalance" for performance boosts. Cheers, -PJ -- 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/