From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755733Ab2FYKil (ORCPT ); Mon, 25 Jun 2012 06:38:41 -0400 Received: from casper.infradead.org ([85.118.1.10]:42263 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753609Ab2FYKik (ORCPT ); Mon, 25 Jun 2012 06:38:40 -0400 Subject: Re: [BUG] sched: clock wrap bug in 2.6.35-stable kills scheduling From: Peter Zijlstra To: Thomas Lange Cc: mingo@redhat.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org In-Reply-To: <1340617541.2507.50.camel@laptop> References: <4FE74F1B.6070803@corelatus.se> <1340617541.2507.50.camel@laptop> Content-Type: text/plain; charset="UTF-8" Date: Mon, 25 Jun 2012 12:38:26 +0200 Message-ID: <1340620706.2507.51.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2012-06-25 at 11:45 +0200, Peter Zijlstra wrote: > On Sun, 2012-06-24 at 19:32 +0200, Thomas Lange wrote: > > Bug was introduced in 2.6.35.12 and is still present in linux-2.6.35.y HEAD. > > Ok, so nobody cares about that.. what does something recent like 3.5-rc4 > do? > > If that's fixed, find the patch that fixes it. If not, we'll have a > look. If anything, I think something like the below ought to cure things. --- kernel/sched/clock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index c685e31..a1a128a 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -74,7 +74,7 @@ */ unsigned long long __attribute__((weak)) sched_clock(void) { - return (unsigned long long)(jiffies - INITIAL_JIFFIES) + return (unsigned long long)(get_jiffies_64() - INITIAL_JIFFIES) * (NSEC_PER_SEC / HZ); } EXPORT_SYMBOL_GPL(sched_clock);