From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754258AbYAIU0r (ORCPT ); Wed, 9 Jan 2008 15:26:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753884AbYAIU0d (ORCPT ); Wed, 9 Jan 2008 15:26:33 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:54158 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756233AbYAIU0b (ORCPT ); Wed, 9 Jan 2008 15:26:31 -0500 Date: Wed, 9 Jan 2008 12:25:59 -0800 From: Arjan van de Ven To: Andi Kleen Cc: Ingo Molnar , Andi Kleen , tglx@linutronix.de, linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: More breakage in native_rdtsc out of line in git-x86 Message-ID: <20080109122559.38bc8c33@laptopd505.fenrus.org> In-Reply-To: <20080109174800.GA15346@one.firstfloor.org> References: <20080109035534.GA30321@basil.nowhere.org> <20080109090956.GA14274@elte.hu> <20080109141908.GB12855@one.firstfloor.org> <20080109152208.GA21280@elte.hu> <20080109155124.GB12923@one.firstfloor.org> <20080109163017.GG17739@elte.hu> <20080109174800.GA15346@one.firstfloor.org> Organization: Intel X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.1; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Jan 2008 18:48:00 +0100 > And after all that's still by far the most common system call > (not only for databases; i profiled this using systemtap in some > loads some time ago and it usually came up with >50%) > and quite important for many workloads. > btw be careful with this; the X server uses gettimeofday in it's equivalent of udelay()... (and we all know how useful it is to make the delay loops faster ;-)