Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754135AbXFYWtk (ORCPT ); Mon, 25 Jun 2007 18:49:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752631AbXFYWtd (ORCPT ); Mon, 25 Jun 2007 18:49:33 -0400 Received: from scrub.xs4all.nl ([194.109.195.176]:2514 "EHLO scrub.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558AbXFYWtd (ORCPT ); Mon, 25 Jun 2007 18:49:33 -0400 Date: Tue, 26 Jun 2007 00:49:47 +0200 (CEST) From: Roman Zippel X-X-Sender: roman@scrub.home To: Jesper Juhl cc: Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton , John Stultz , Thomas Gleixner Subject: Re: [patch, v2.6.22-rc6] sys_time() speedup In-Reply-To: <9a8748490706251520g24ff7a9dk716d73e7dbfd9ec3@mail.gmail.com> Message-ID: References: <20070625200601.GA18980@elte.hu> <200706252309.47467.zippel@linux-m68k.org> <9a8748490706251417v10b3f24bwdf7ebd44093eaddf@mail.gmail.com> <9a8748490706251520g24ff7a9dk716d73e7dbfd9ec3@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 918 Lines: 25 Hi, On Tue, 26 Jun 2007, Jesper Juhl wrote: > Even if it is not faster, what would make it slower? Have you spotted > something I have not? There are other ways to read the clock and would require similiar synchronization hooks. Some archs can implement sys_time() in userspace, so there this change would be useless. I don't know what clock was used in the test, so maybe it can be replaced with a faster clock. AFAICT OLTP is not really a common application for most users, so there may be other ways to optimize this special case. Just reading the patch isn't enough here, you have to look at the whole picture and some pieces are still missing... bye, Roman - 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/