Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261754AbVAYCPj (ORCPT ); Mon, 24 Jan 2005 21:15:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261759AbVAYCPj (ORCPT ); Mon, 24 Jan 2005 21:15:39 -0500 Received: from gateway-1237.mvista.com ([12.44.186.158]:4852 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S261754AbVAYCPc (ORCPT ); Mon, 24 Jan 2005 21:15:32 -0500 Message-ID: <41F5ABB8.8070308@mvista.com> Date: Mon, 24 Jan 2005 18:15:20 -0800 From: George Anzinger Reply-To: george@mvista.com Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.2) Gecko/20040308 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Roland McGrath CC: Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org, Christoph Lameter , Ulrich Drepper Subject: Re: [PATCH 1/7] posix-timers: tidy up clock interfaces and consolidate dispatch logic References: <200501232322.j0NNMcxe006476@magilla.sf.frob.com> In-Reply-To: <200501232322.j0NNMcxe006476@magilla.sf.frob.com> 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: 1254 Lines: 28 Where were you when I was writing this stuff :). I agree with most all of it, save the following: > /* > + * Define this to initialize every k_clock function table so all its > + * function pointers are non-null, and always do indirect calls through the > + * table. Leave it undefined to instead leave null function pointers and > + * decide at the call sites between a direct call (maybe inlined) to the > + * default function and an indirect call through the table when it's filled > + * in. Which style is preferable is whichever performs better in the > + * common case of using the default functions. > +#define CLOCK_DISPATCH_DIRECT As I understand it modern machines, the indirect call does really bad things to the pipeline. The default call, even preceeded by the if, will be much faster by this reasoning. I would, therefor, prefer not defining CLOCK_DISPATCH_DIRECT. -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ - 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/