Messages in this thread Patch in this message | | | Date | Tue, 4 Dec 2012 11:10:57 -0800 | From | tip-bot for Thomas Gleixner <> | Subject | [tip:core/urgent] watchdog: Fix CPU hotplug regression |
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Commit-ID: 8d4516904b39507458bee8115793528e12b1d8dd Gitweb: http://git.kernel.org/tip/8d4516904b39507458bee8115793528e12b1d8dd Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Tue, 4 Dec 2012 18:59:34 +0100 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 4 Dec 2012 19:56:59 +0100
watchdog: Fix CPU hotplug regression
Norbert reported: "3.7-rc6 booted with nmi_watchdog=0 fails to suspend to RAM or offline CPUs. It's reproducable with a KVM guest and physical system."
The reason is that commit bcd951cf(watchdog: Use hotplug thread infrastructure) missed to take this into account. So the cpu offline code gets stuck in the teardown function because it accesses non initialized data structures.
Add a check for watchdog_enabled into that path to cure the issue.
Reported-and-tested-by: Norbert Warmuth <nwarmuth@t-online.de> Tested-by: Joseph Salisbury <joseph.salisbury@canonical.com> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1211231033230.2701@ionos Link: http://bugs.launchpad.net/bugs/1079534 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/watchdog.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index dd4b80a..c8c21be 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -368,6 +368,9 @@ static void watchdog_disable(unsigned int cpu) { struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer); + if (!watchdog_enabled) + return; + watchdog_set_prio(SCHED_NORMAL, 0); hrtimer_cancel(hrtimer); /* disable the perf event */
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