Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264136AbUDVPhx (ORCPT ); Thu, 22 Apr 2004 11:37:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264137AbUDVPhx (ORCPT ); Thu, 22 Apr 2004 11:37:53 -0400 Received: from gw1.cosmosbay.com ([62.23.185.226]:62424 "EHLO gw1.cosmosbay.com") by vger.kernel.org with ESMTP id S264136AbUDVPhv (ORCPT ); Thu, 22 Apr 2004 11:37:51 -0400 Message-ID: <4087E6B1.9000606@cosmosbay.com> Date: Thu, 22 Apr 2004 17:37:21 +0200 From: Eric Dumazet User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113 X-Accept-Language: fr, en-us, en MIME-Version: 1.0 To: James Morris CC: Andi Kleen , linux-kernel@vger.kernel.org, vda@port.imtp.ilyichevsk.odessa.ua Subject: Re: Large inlines in include/linux/skbuff.h References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1156 Lines: 38 James Morris wrote: >On Thu, 22 Apr 2004, Andi Kleen wrote: > > > >>>How will these changes impact performance? I asked this last time you >>>posted about inlines and didn't see any response. >>> >>> >>I don't think it will be an issue. The optimization guidelines >>of AMD and Intel recommend to move functions that generate >>more than 30-40 instructions out of line. 100 instructions >>is certainly enough to amortize the call overhead, and you >>safe some icache too so it may be even faster. >> >> > >Of course, but it would be good to see some measurements. > > >- James > > It depends a lot of the workload of the machine. If this a specialized machine, with a small program that mostly uses recv() & send() syscalls, then, inlining functions is a gain, since icache may have a 100% hit ratio. Optimization guidelines are good for the common cases, not every cases. Eric Dumazet - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/