Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761889AbXH1U1x (ORCPT ); Tue, 28 Aug 2007 16:27:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754545AbXH1U1o (ORCPT ); Tue, 28 Aug 2007 16:27:44 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:50413 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753036AbXH1U1n (ORCPT ); Tue, 28 Aug 2007 16:27:43 -0400 Date: Tue, 28 Aug 2007 13:27:41 -0700 (PDT) Message-Id: <20070828.132741.118957759.davem@davemloft.net> To: ossthema@de.ibm.com Cc: jchapman@katalix.com, shemminger@linux-foundation.org, akepner@sgi.com, netdev@vger.kernel.org, raisch@de.ibm.com, themann@de.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, meder@de.ibm.com, tklein@de.ibm.com, stefan.roscher@de.ibm.com Subject: Re: RFC: issues concerning the next NAPI interface From: David Miller In-Reply-To: <200708281321.10679.ossthema@de.ibm.com> References: <46D2F301.7050105@katalix.com> <20070827.140251.95055210.davem@davemloft.net> <200708281321.10679.ossthema@de.ibm.com> X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 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: 896 Lines: 22 From: Jan-Bernd Themann Date: Tue, 28 Aug 2007 13:21:09 +0200 > So I guess one solution is to "force" an HW interrupt when two many > RQs are processed on the same CPU (when no IRQ pinning is > used). This is something the driver has to handle. No, the solution is to lock the interrupts onto one specific processor and don't move it around. That's what's causing all of the problems. And you can enforce this policy now in the driver even if just for testing by calling the set_affinity() interfaces on the interrupts your driver has. You can even walk over the cpu_online_map and choose a load distribution of your liking. - 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/