From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: question about softirqs Date: Wed, 13 May 2009 17:02:42 +0200 Message-ID: <20090513150242.GX19296@one.firstfloor.org> References: <20090511.162436.193717082.davem@davemloft.net> <4A08C62F.1050105@nortel.com> <20090512081237.GA16403@elte.hu> <4A09933B.8010606@nortel.com> <874ovpmmdq.fsf@basil.nowhere.org> <4A0AC9EC.6070908@nortel.com> <20090513141532.GT19296@one.firstfloor.org> <87my9hkrmw.fsf@basil.nowhere.org> <4A0ADF34.2040001@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , Thomas Gleixner , Chris Friesen , Ingo Molnar , Peter Zijlstra , Steven Rostedt , David Miller , linuxppc-dev@ozlabs.org, paulus@samba.org, netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from one.firstfloor.org ([213.235.205.2]:53916 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752139AbZEMO5T (ORCPT ); Wed, 13 May 2009 10:57:19 -0400 Content-Disposition: inline In-Reply-To: <4A0ADF34.2040001@cosmosbay.com> Sender: netdev-owner@vger.kernel.org List-ID: > I have one machine SMP flooded by network frames, CPU0 handling all Yes that's the case softirqd is supposed to handle. When you spend a significant part of your CPU time in softirq context it kicks in to provide somewhat fair additional CPU time. But most systems (like mine) don't do that. -Andi -- ak@linux.intel.com -- Speaking for myself only. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from one.firstfloor.org (one.firstfloor.org [213.235.205.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1B9BFDDFDC for ; Thu, 14 May 2009 00:57:25 +1000 (EST) Date: Wed, 13 May 2009 17:02:42 +0200 From: Andi Kleen To: Eric Dumazet Subject: Re: question about softirqs Message-ID: <20090513150242.GX19296@one.firstfloor.org> References: <20090511.162436.193717082.davem@davemloft.net> <4A08C62F.1050105@nortel.com> <20090512081237.GA16403@elte.hu> <4A09933B.8010606@nortel.com> <874ovpmmdq.fsf@basil.nowhere.org> <4A0AC9EC.6070908@nortel.com> <20090513141532.GT19296@one.firstfloor.org> <87my9hkrmw.fsf@basil.nowhere.org> <4A0ADF34.2040001@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4A0ADF34.2040001@cosmosbay.com> Cc: Peter Zijlstra , linuxppc-dev@ozlabs.org, netdev@vger.kernel.org, Steven Rostedt , David Miller , Andi Kleen , paulus@samba.org, Thomas Gleixner , Ingo Molnar List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > I have one machine SMP flooded by network frames, CPU0 handling all Yes that's the case softirqd is supposed to handle. When you spend a significant part of your CPU time in softirq context it kicks in to provide somewhat fair additional CPU time. But most systems (like mine) don't do that. -Andi -- ak@linux.intel.com -- Speaking for myself only.