Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261468AbUDVWX2 (ORCPT ); Thu, 22 Apr 2004 18:23:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263355AbUDVWX2 (ORCPT ); Thu, 22 Apr 2004 18:23:28 -0400 Received: from colin2.muc.de ([193.149.48.15]:50706 "HELO colin2.muc.de") by vger.kernel.org with SMTP id S261468AbUDVWX1 (ORCPT ); Thu, 22 Apr 2004 18:23:27 -0400 Date: 23 Apr 2004 00:23:26 +0200 Date: Fri, 23 Apr 2004 00:23:26 +0200 From: Andi Kleen 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 Message-ID: <20040422222326.GA81305@colin2.muc.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1023 Lines: 24 On Thu, Apr 22, 2004 at 11:15:47AM -0400, 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. It's useless in this case. networking is dominated by cache misses and locks and a modern CPU can do hundreds of function calls in a single cache miss. -Andi - 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/