Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 3 Jul 2002 08:28:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 3 Jul 2002 08:28:12 -0400 Received: from cpe-66-1-218-52.fl.sprintbbd.net ([66.1.218.52]:42765 "EHLO daytona.compro.net") by vger.kernel.org with ESMTP id ; Wed, 3 Jul 2002 08:28:10 -0400 Message-ID: <3D22EEB0.B3266763@compro.net> Date: Wed, 03 Jul 2002 08:31:44 -0400 From: Mark Hounschell Reply-To: markh@compro.net Organization: Compro Computer Svcs. X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.18-lcrs i686) X-Accept-Language: en MIME-Version: 1.0 To: Stephane Charette CC: "linux-kernel@vger.kernel.org" Subject: Re: performance impact of using noapic References: <20020702192006Z316884-686+254@vger.kernel.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 865 Lines: 31 Stephane Charette wrote: > > My questions are: > > 1) am I right in thinking that "noapic" will force all interrupts to be handled by 1 CPU? Yes. > > 2) how would you force all interrupts from only 1 hardware device (and not all devices) to be handled by 1 processor, as hinted in the paragraph quoted above? echo "00000001" > /proc/irq/19/smp_affinity Will cause irq 19 to be serviced by processor 1 echo "00000003" > /proc/irq/19/smp_affinity Will allow irq 19 to be serviced by processor 1 and 2 You could also do this in the driver if you wanted. Note that this will not work when noapic is used.. Mark - 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/