From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: Re: [PATCH v3] net: batch skb dequeueing from softnet input_pkt_queue Date: Wed, 14 Apr 2010 20:13:20 +0800 Message-ID: References: <1271238738-8386-1-git-send-email-xiaosuo@gmail.com> <1271246304.3943.60.camel@bigi> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "David S. Miller" , Eric Dumazet , netdev@vger.kernel.org To: hadi@cyberus.ca Return-path: Received: from mail-yx0-f199.google.com ([209.85.210.199]:38966 "EHLO mail-yx0-f199.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755073Ab0DNMNu convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2010 08:13:50 -0400 Received: by yxe37 with SMTP id 37so19910yxe.21 for ; Wed, 14 Apr 2010 05:13:49 -0700 (PDT) In-Reply-To: <1271246304.3943.60.camel@bigi> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Apr 14, 2010 at 7:58 PM, jamal wrote: > > It seems we are now going to generate a lot more IPIs with such a > change. At least this is what i am imagining. > CPU0: packet comes in,queue empty, generate an IPI to CPU1 > CPU0: second packet comes in, enqueue > CPU1: grab two packets to process and run with them > CPU0: packet comes in,queue empty, generate an IPI to CPU1 No extra IPI is needed. + qlen =3D queue->input_pkt_queue.qlen + queue->processing_queue.= qlen; + if (qlen <=3D netdev_max_backlog) { + if (qlen) { the packets in processing_queue are counted too. > > IPIs add to latency (refer to my other email). Did you test this > to reach some conclusion that it improves thing or was it just by > inspection? > :( only insepection. --=20 Regards=EF=BC=8C Changli Gao(xiaosuo@gmail.com)