From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH v3] net: batch skb dequeueing from softnet input_pkt_queue Date: Wed, 14 Apr 2010 07:58:24 -0400 Message-ID: <1271246304.3943.60.camel@bigi> References: <1271238738-8386-1-git-send-email-xiaosuo@gmail.com> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Eric Dumazet , netdev@vger.kernel.org To: Changli Gao Return-path: Received: from qw-out-2122.google.com ([74.125.92.26]:51329 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755031Ab0DNL61 (ORCPT ); Wed, 14 Apr 2010 07:58:27 -0400 Received: by qw-out-2122.google.com with SMTP id 8so1939qwh.37 for ; Wed, 14 Apr 2010 04:58:27 -0700 (PDT) In-Reply-To: <1271238738-8386-1-git-send-email-xiaosuo@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2010-04-14 at 17:52 +0800, Changli Gao wrote: > batch skb dequeueing from softnet input_pkt_queue > > batch skb dequeueing from softnet input_pkt_queue to reduce potential lock > contention and irq disabling/enabling. > > Signed-off-by: Changli Gao 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 .. ... ..... 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? cheers, jamal