From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762796AbYFFSbU (ORCPT ); Fri, 6 Jun 2008 14:31:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755455AbYFFSbL (ORCPT ); Fri, 6 Jun 2008 14:31:11 -0400 Received: from one.firstfloor.org ([213.235.205.2]:48630 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751713AbYFFSbK (ORCPT ); Fri, 6 Jun 2008 14:31:10 -0400 Date: Fri, 6 Jun 2008 20:40:48 +0200 From: Andi Kleen To: Andrew Morton Cc: Andi Kleen , Denys Fedoryshchenko , linux-kernel@vger.kernel.org Subject: Re: strange timestamp in dmesg Message-ID: <20080606184048.GB13101@one.firstfloor.org> References: <20080605115256.M13181@visp.net.lb> <20080606031939.285679c9.akpm@linux-foundation.org> <87hcc6u109.fsf@basil.nowhere.org> <20080606112547.13b78888.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080606112547.13b78888.akpm@linux-foundation.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 06, 2008 at 11:25:47AM -0700, Andrew Morton wrote: > We've seen a storm of hey-my-timestamps-went-weird reports in just the > past month or so. I don't recall it being (such) a problem before that. > > Did we change something Nominally not, but who really knows with 5 digit number worth of changesets? At least 64bit should have been always like this, but you only see it on specific circumstances. > > I always advocated just always using jiffies for printk. The only drawback would > > be that it won't increase in interrupt off sections, but if you have > > one that is longer than a jiffie then you have enough other problems. > > I forget why, but we _were_ going to have an (arch-overrideable) > printk_clock() function. And we still could. The x86 implementation > of that could fall back to jiffies if the TSCs are out of whack? The rewritten sched_clock I used to plug, but which yielded about zero interest, had one. -Andi