linux-kernel - [PATCH 0/3] watchdog: kvm: disable hard lockup detection by default

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Message-Id: <1406196811-5384-1-git-send-email-drjones@redhat.com>
Date:	Thu, 24 Jul 2014 12:13:28 +0200
From:	Andrew Jones <drjones@...hat.com>
To:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:	uobergfe@...hat.com, dzickus@...hat.com, pbonzini@...hat.com,
	akpm@...ux-foundation.org, mingo@...hat.com
Subject: [PATCH 0/3] watchdog: kvm: disable hard lockup detection by default

It's not recommended for KVM guests to enable hard lockup detection, as
false positives may be easily triggered by, for example, vcpu overcommit.
However any kernel compiled with HARDLOCKUP_DETECTOR that detects a PMU
on boot will by default enable hard lockup detection. This series gives
a kernel a mechanism to opt out of this default. Users can still force
hard lockup detection on using the kernel command line option
'nmi_watchdog=1'.

The first patch is a watchdog fix, and can be taken separately. The next
patch provides the default opt out mechanism, and the final patch applies
it to kvm guests.

Thanks in advance for reviews,
drew

Ulrich Obergfell (3):
  watchdog: fix print-once on enable
  watchdog: control hard lockup detection default
  kvm: ensure hard lockup detection is disabled by default

 arch/x86/kernel/kvm.c |  8 ++++++++
 include/linux/nmi.h   |  9 +++++++++
 kernel/watchdog.c     | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 63 insertions(+), 2 deletions(-)

-- 
1.9.3

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