From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936753AbXGSPF4 (ORCPT ); Thu, 19 Jul 2007 11:05:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763252AbXGSPF0 (ORCPT ); Thu, 19 Jul 2007 11:05:26 -0400 Received: from gw.goop.org ([64.81.55.164]:53309 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965083AbXGSPFV (ORCPT ); Thu, 19 Jul 2007 11:05:21 -0400 Message-ID: <469F7D7A.204@goop.org> Date: Thu, 19 Jul 2007 08:04:26 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.4 (X11/20070615) MIME-Version: 1.0 To: Ingo Molnar CC: Andrew Morton , linux-kernel@vger.kernel.org, Linus Torvalds , stable@kernel.org, Greg KH , Chris Wright Subject: Re: [patch] fix the softlockup watchdog to actually work References: <20070717114453.GA8212@elte.hu> <469CCF8F.4010107@goop.org> <20070717154934.GA24231@elte.hu> <20070719002231.069ebbdd.akpm@linux-foundation.org> <20070719075152.GB12760@elte.hu> <469F75AF.5080000@goop.org> <20070719143528.GA8278@elte.hu> <469F793E.6030006@goop.org> <20070719145058.GA11971@elte.hu> In-Reply-To: <20070719145058.GA11971@elte.hu> X-Enigmail-Version: 0.95.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > no, the return value after idling can be completely random on some > boxes, on a 64-bit scale - triggering the softlockup watchdog randomly. > (some boxes return random TSC values, etc.) Again, it's fine for the > scheduler's purpose, that's why i named it sched_clock(). > > the proper clocksource use within the kernel is ktime_get() [or > ktime_get_ts()]. Do not abuse sched_clock() for such things. Well, my observation is that both softlockup and the scheduler really want to measure unstolen time, so it seemed to me that sched_clock was a nice common place to implement that, rather than implementing a whole new time interface. At the time that seemed OK, and nobody had any objections. But it's a bit beside the point unless it does turn out to be making Andrew's Vaio sad. J