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

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

             reply	other threads:[~2014-07-24 10:13 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-24 10:13 Andrew Jones [this message]
2014-07-24 10:13 ` [PATCH 1/3] watchdog: fix print-once on enable Andrew Jones
2014-07-24 10:13 ` [PATCH 2/3] watchdog: control hard lockup detection default Andrew Jones
2014-07-24 10:46   ` Paolo Bonzini
2014-07-24 11:18     ` Ulrich Obergfell
2014-07-24 11:26       ` Paolo Bonzini
2014-07-24 11:44         ` Ulrich Obergfell
2014-07-24 11:45           ` Paolo Bonzini
2014-07-24 12:02             ` Ulrich Obergfell
2014-07-25  8:32   ` Ulrich Obergfell
2014-07-25 11:25     ` Andrew Jones
2014-07-30 13:43       ` Don Zickus
2014-07-30 14:16         ` Paolo Bonzini
2014-07-30 17:07           ` Don Zickus
2014-08-08 13:53   ` [PATCH v2 " Andrew Jones
2014-07-24 10:13 ` [PATCH 3/3] kvm: ensure hard lockup detection is disabled by default Andrew Jones

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