From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH net-next-2.6] filter: optimize sk_run_filter Date: Fri, 19 Nov 2010 09:15:37 -0800 Message-ID: <20101119091537.5d1fed2e@nehalam> References: <1290165472.3034.109.camel@edumazet-laptop> <20101119.082125.193710226.davem@davemloft.net> <1290185759.3034.179.camel@edumazet-laptop> <20101119.090516.104057453.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, hagen@jauu.net, netdev@vger.kernel.org, xiaosuo@gmail.com To: David Miller Return-path: Received: from mail.vyatta.com ([76.74.103.46]:60876 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755811Ab0KSRPk (ORCPT ); Fri, 19 Nov 2010 12:15:40 -0500 In-Reply-To: <20101119.090516.104057453.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 19 Nov 2010 09:05:16 -0800 (PST) David Miller wrote: > From: Eric Dumazet > Date: Fri, 19 Nov 2010 17:55:59 +0100 > > > Unfortunatly on x86_32 it also chose that f_k was more valuable in a cpu > > register and accumulator A lost its register to get a stack slot > > instead. > > Ok that tradeoff is terrible, but it depends upon knowledge we haven't > given to the compiler (yet). > > Let me think about this a bit... Are 'register' modifiers a no-op on current GCC?