Messages in this thread | | | Date | Fri, 12 Aug 2011 18:59:12 +0100 | From | Matthew Garrett <> | Subject | Re: pstore: change mutex locking to spin_locks |
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On Fri, Aug 12, 2011 at 10:54:51AM -0700, Luck, Tony wrote: > From: Don Zickus <dzickus@redhat.com> > > pstore was using mutex locking to protect read/write access to the > backend plug-ins. This causes problems when pstore is executed in > an NMI context through panic() -> kmsg_dump(). > > This patch changes the mutex to a spin_lock_irqsave then also checks to > see if we are in an NMI context. If we are in an NMI and can't get the > lock, just print a message stating that and blow by the locking. > > All this is probably a hack around the bigger locking problem but it > solves my current situation of trying to sleep in an NMI context. > > Tested by loading the lkdtm module and executing a HARDLOCKUP which > will cause the machine to panic inside the nmi handler. > > Signed-off-by: Don Zickus <dzickus@redhat.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> Acked-by: Matthew Garrett <mjg@redhat.com>
-- Matthew Garrett | mjg59@srcf.ucam.org
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