From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755870Ab3JHWI2 (ORCPT ); Tue, 8 Oct 2013 18:08:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25054 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753397Ab3JHWI0 (ORCPT ); Tue, 8 Oct 2013 18:08:26 -0400 Date: Tue, 8 Oct 2013 19:08:11 -0300 From: Marcelo Tosatti To: Don Zickus Cc: kvm@vger.kernel.org, pbonzini@redhat.com, gleb@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [patch 2/3] pvclock: detect watchdog reset at pvclock read Message-ID: <20131008220811.GC16625@amt.cnet> References: <20131008010515.516032211@amt.cnet> <20131008010552.779616517@amt.cnet> <20131008133705.GR227855@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131008133705.GR227855@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 08, 2013 at 09:37:05AM -0400, Don Zickus wrote: > On Mon, Oct 07, 2013 at 10:05:17PM -0300, Marcelo Tosatti wrote: > > Implement reset of kernel watchdogs at pvclock read time. This avoids > > adding special code to every watchdog. > > > > This is possible for watchdogs which measure time based on sched_clock() or > > ktime_get() variants. > > > > Suggested by Don Zickus. > > > > Signed-off-by: Marcelo Tosatti > > Awesome. Thanks for figuring this out Marcelo. Does that mean we can > revert commit 5d1c0f4a now? :-) Unfortunately no: soft lockup watchdog does not measure time based on sched_clock but on hrtimer interrupt count :-( (see the the softlockup code in question, perhaps you can point to something that i'm missing). BTW, are you OK with printing additional steal time information? https://lkml.org/lkml/2013/6/27/755 > This meets my expectations. I'll leave it to the virt folks to figure out > if this covers all the corner cases or not. > > Cheers, > Don Thanks