From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934008AbXC0Fs7 (ORCPT ); Tue, 27 Mar 2007 01:48:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934030AbXC0Fs7 (ORCPT ); Tue, 27 Mar 2007 01:48:59 -0400 Received: from gw.goop.org ([64.81.55.164]:59342 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934008AbXC0Fs6 (ORCPT ); Tue, 27 Mar 2007 01:48:58 -0400 Message-Id: <20070327053816.881735237@goop.org> User-Agent: quilt/0.46-1 Date: Mon, 26 Mar 2007 22:38:16 -0700 From: Jeremy Fitzhardinge To: Andrew Morton Cc: Linux Kernel , virtualization@lists.osdl.org, Ingo Molnar , Thomas Gleixner , john stultz Subject: [patch 0/2] softlockup watchdog improvements Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Here's couple of patches to improve the softlockup watchdog. The first changes the softlockup timer from using jiffies to sched_clock() as a timebase. Xen and VMI implement sched_clock() as counting unstolen time, so time stolen by the hypervisor won't cause the watchdog to bite. The second adds per-cpu enable flags for the watchdog timer. This allows the timer to be disabled when the CPU goes into a (potentially unbounded) tickless sleep. I know this conflicts with fix-bogus-softlockup-warning-with-sysrq-t.patch in -mm2. I think that patch incorrectly changes the behaviour of the softlockup watchdog, and a better solution is to temporarily disable the watchdog while doing something known to be cpu-consuming, like a long sysreq output. J --