Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030399AbWHRN4m (ORCPT ); Fri, 18 Aug 2006 09:56:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030407AbWHRN4m (ORCPT ); Fri, 18 Aug 2006 09:56:42 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:16291 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1030399AbWHRN4l (ORCPT ); Fri, 18 Aug 2006 09:56:41 -0400 Subject: Re: [2.6.19 PATCH 1/7] ehea: interface to network stack From: Arjan van de Ven To: Alexey Dobriyan Cc: Jan-Bernd Themann , netdev@vger.kernel.org, Christoph Raisch , Jan-Bernd Themann , linux-kernel , linux-ppc , Marcus Eder , Thomas Klein , Thomas Klein In-Reply-To: <20060818134728.GB5201@martell.zuzino.mipt.ru> References: <200608181329.02042.ossthema@de.ibm.com> <20060818134728.GB5201@martell.zuzino.mipt.ru> Content-Type: text/plain Organization: Intel International BV Date: Fri, 18 Aug 2006 15:56:17 +0200 Message-Id: <1155909377.4494.192.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 909 Lines: 22 On Fri, 2006-08-18 at 17:47 +0400, Alexey Dobriyan wrote: > On Fri, Aug 18, 2006 at 01:29:01PM +0200, Jan-Bernd Themann wrote: > > Was there noticeable performance difference when explicit prefetching is > removed? At some (invisible) point CPUs will become smarter about prefetching > than programmers and this code will be slower than possible. Hi, what you say is true in general, however the packet response part of the kernel is special; the cpu just cannot know where your card just dma'd the packet to (and thus cleared it from any caches anywhere in the system) so it's going to be pretty much a 100% cachemiss always... Greetings, Arjan van de Ven - 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/