From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: [RFC 6/7] touch softlockup watchdog Date: Wed, 25 Aug 2010 17:43:16 -0400 Message-ID: <1282772597-4183-7-git-send-email-glommer@redhat.com> References: <1282772597-4183-1-git-send-email-glommer@redhat.com> <1282772597-4183-2-git-send-email-glommer@redhat.com> <1282772597-4183-3-git-send-email-glommer@redhat.com> <1282772597-4183-4-git-send-email-glommer@redhat.com> <1282772597-4183-5-git-send-email-glommer@redhat.com> <1282772597-4183-6-git-send-email-glommer@redhat.com> Cc: avi@redhat.com, zamsden@redhat.com, mtosatti@redhat.com, riel@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:58913 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308Ab0HYV7V (ORCPT ); Wed, 25 Aug 2010 17:59:21 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7PLxKPY022013 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 25 Aug 2010 17:59:21 -0400 In-Reply-To: <1282772597-4183-6-git-send-email-glommer@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: With a reliable steal time mechanism, we can tell if we're out of the cpu for very long, differentiating from the case that we simply got a real softlockup. In the case we were out of cpu, the watchdog is fed, making bogus softlockups disappear. Signed-off-by: Glauber Costa --- arch/x86/kernel/kvmclock.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index a1f4852..1c496c8 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -104,6 +104,9 @@ cputime_t kvm_get_steal_time(void) delta = this_steal_info - *last_steal_info; + if (delta > 1000UL) + touch_softlockup_watchdog(); + *last_steal_info = this_steal_info; put_cpu_var(steal_info); -- 1.6.2.2