From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030634AbXDLR5O (ORCPT ); Thu, 12 Apr 2007 13:57:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030636AbXDLR5O (ORCPT ); Thu, 12 Apr 2007 13:57:14 -0400 Received: from smtp.osdl.org ([65.172.181.24]:52928 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030634AbXDLR5N (ORCPT ); Thu, 12 Apr 2007 13:57:13 -0400 Date: Thu, 12 Apr 2007 10:55:59 -0700 From: Andrew Morton To: Jeremy Fitzhardinge Cc: Andi Kleen , Daniel Walker , linux-kernel@vger.kernel.org, johnstul@us.ibm.com, tglx@linutronix.de Subject: Re: [PATCH] i386 tsc: remove xtime_lock'ing around cpufreq notifier Message-Id: <20070412105559.385789dd.akpm@linux-foundation.org> In-Reply-To: <461E6FA7.5080605@goop.org> References: <20070411162904.232696302@mvista.com> <200704121136.03098.ak@novell.com> <20070412092348.70a4de05.akpm@linux-foundation.org> <200704121845.39961.ak@novell.com> <20070412100039.00ace23f.akpm@linux-foundation.org> <461E6FA7.5080605@goop.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 12 Apr 2007 10:43:03 -0700 Jeremy Fitzhardinge wrote: > Andrew Morton wrote: > > hm. People (ab)use sched_clock() for all sorts of things nowadays. I wouldn't > > do anything to degrade it just on behalf of printk-timestamping. > > > > printk was the only non-scheduler-ish use I could find. Are there others? > blktrace. I've seen a couple of trace/debug-style things which use sched_clock for timestamping event collection. I think lttng does exotic things with TSCs, performing private skew correction, although that might have changed now.