From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755865AbbAIDfB (ORCPT ); Thu, 8 Jan 2015 22:35:01 -0500 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:48199 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754785AbbAIDe7 (ORCPT ); Thu, 8 Jan 2015 22:34:59 -0500 From: Cyril Bur To: linux-kernel@vger.kernel.org Cc: mpe@ellerman.id.au, drjones@redhat.com, dzickus@redhat.com, akpm@linux-foundation.org, mingo@kernel.org, uobergfe@redhat.com, chaiw.fnst@cn.fujitsu.com, fabf@skynet.be, atomlin@redhat.com, benzh@chromium.org, schwidefsky@de.ibm.com, Cyril Bur Subject: [PATCH v2 0/2] Quieten softlockup detector on virtualised kernels Date: Fri, 9 Jan 2015 14:34:36 +1100 Message-Id: <1420774478-16760-1-git-send-email-cyrilbur@gmail.com> X-Mailer: git-send-email 1.9.1 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15010903-0033-0000-0000-000000E60354 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the hypervisor pauses a virtualised kernel the kernel will observe a jump in timebase, this can cause spurious messages from the softlockup detector. Whilst these messages are harmless, they are accompanied with a stack trace which causes undue concern and more problematically the stack trace in the guest has nothing to do with the observed problem and can only be misleading. Futhermore, on POWER8 this is completely avoidable with the introduction of the Virtual Time Base (VTB) register. V2: Remove the export of running_clock Added #ifdef CONFIG_PPC_PSERIES and optimised the non lpar + vtb cases. Replaced the use of sched_clock_with local_clock it was used originally in the softlockup detector. Cyril Bur (2): Add another clock for use with the soft lockup watchdog. powerpc: add running_clock for powerpc to prevent spurious softlockup warnings arch/powerpc/kernel/time.c | 32 ++++++++++++++++++++++++++++++++ include/linux/sched.h | 1 + kernel/sched/clock.c | 13 +++++++++++++ kernel/watchdog.c | 2 +- 4 files changed, 47 insertions(+), 1 deletion(-) -- 1.9.1