Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759325AbXH1MRT (ORCPT ); Tue, 28 Aug 2007 08:17:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753381AbXH1MRG (ORCPT ); Tue, 28 Aug 2007 08:17:06 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:57597 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752335AbXH1MRE (ORCPT ); Tue, 28 Aug 2007 08:17:04 -0400 Date: Tue, 28 Aug 2007 16:16:19 +0400 From: Evgeniy Polyakov To: Jan-Bernd Themann Cc: James Chapman , David Miller , 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 Message-ID: <20070828121617.GA4160@2ka.mipt.ru> References: <46D2F301.7050105@katalix.com> <20070827.145600.102570576.davem@davemloft.net> <46D3E971.4010909@katalix.com> <200708281348.21302.ossthema@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200708281348.21302.ossthema@de.ibm.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1213 Lines: 23 On Tue, Aug 28, 2007 at 01:48:20PM +0200, Jan-Bernd Themann (ossthema@de.ibm.com) wrote: > I'm not sure if I understand your approach correctly. > This approach may reduce the number of interrupts, but it does so > by blocking the CPU for up to 1 jiffy (that can be quite some time > on some platforms). So no other application / tasklet / softIRQ type > can do anything in between. The CPU utilization does not drop at all, > and I thought that is one reason why we try to reduce the number of interrupts. Only NICs interrupts are suposed to be stopped, system will continue to work as usual, since all others are alive. Having hrtimer to reshcedule NIC procesing can work only if number of timer's interrupts are much less than NICs and if rate of the timer's starts/changes (presumbly in NICs interrupt) is small too, otherwise having too many NIC interrupts will not gain anything (actually it is what is supposed to be dropped noticebly). -- Evgeniy Polyakov - 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/