From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCN net-next] net: use jump_label for netstamp_needed Date: Wed, 16 Nov 2011 17:47:46 -0500 (EST) Message-ID: <20111116.174746.405217012331368263.davem@davemloft.net> References: <1321366375.2856.12.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:57698 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988Ab1KPWrs (ORCPT ); Wed, 16 Nov 2011 17:47:48 -0500 In-Reply-To: <1321366375.2856.12.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Tue, 15 Nov 2011 15:12:55 +0100 > netstamp_needed seems a good candidate to jump_label conversion. > > This avoids 3 conditional branches per incoming packet in fast path. > > No measurable difference, given that these conditional branches are > predicted on modern cpus. Only a small icache reduction, thanks to the > unlikely() stuff. > > Signed-off-by: Eric Dumazet Applied.