From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: Re: [PATCH net-next-2.6] rps: shortcut net_rps_action() Date: Tue, 20 Apr 2010 08:32:38 +0800 Message-ID: References: <1271590476.16881.4925.camel@edumazet-laptop> <1271669822.16881.7520.camel@edumazet-laptop> <1271679244.3845.43.camel@edumazet-laptop> <1271683627.3845.44.camel@edumazet-laptop> <1271686957.3845.49.camel@edumazet-laptop> <1271689653.3845.73.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , Tom Herbert , netdev To: Eric Dumazet Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:41505 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752454Ab0DTAdB convert rfc822-to-8bit (ORCPT ); Mon, 19 Apr 2010 20:33:01 -0400 Received: by gyg13 with SMTP id 13so2900699gyg.19 for ; Mon, 19 Apr 2010 17:32:59 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Apr 20, 2010 at 7:56 AM, Changli Gao wrote: > > It seems you prefetch rps_ipi_next. I think it isn't necessary, as th= e > list should be short. If you insist on this, is the macro prefetch() > better? Oh, I read the code again and got the answer. After the IPI is sent, this softnet will be queued by the other CPUs. We prefetch the pointer rps_ipi_next to avoid this race condition. Sorry for noise :) --=20 Regards=EF=BC=8C Changli Gao(xiaosuo@gmail.com)