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Ashok Raj authored
commit d90167a9 upstream. Intel's MCA implementation broadcasts MCEs to all CPUs on the node. This poses a problem for offlined CPUs which cannot participate in the rendezvous process: Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler Kernel Offset: disabled Rebooting in 100 seconds.. More specifically, Linux does a soft offline of a CPU when writing a 0 to /sys/devices/system/cpu/cpuX/online, which doesn't prevent the #MC exception from being broadcasted to that CPU. Ensure that offline CPUs don't participate in the MCE rendezvous and clear the RIP valid status bit so that a second MCE won't cause a shutdown. Without the patch, mce_start() will increment mce_callin and wait for all CPUs. Offlined CPUs should avoid participating in the rendezvous process altogether. Signed-off-by:
Ashok Raj <ashok.raj@intel.com> [ Massage commit message. ] Signed-off-by:
Borislav Petkov <bp@suse.de> Reviewed-by:
Tony Luck <tony.luck@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1449742346-21470-2-git-send-email-bp@alien8.deSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> [ luis: backported to 3.16: adjusted context ] Signed-off-by:
Luis Henriques <luis.henriques@canonical.com>
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