Commit 63a809a2 authored May 01, 2009 by Peter Zijlstra Committed by Ingo Molnar May 01, 2009

perf_counter: fix nmi-watchdog interaction



When we don't have any perf-counters active, don't act like we know
what the NMI is for.

[ Impact: fix hard hang with nmi_watchdog=2 ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.109867793@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent c33a0bc4

arch/x86/kernel/cpu/perf_counter.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -871,6 +871,9 @@ perf_counter_nmi_handler(struct notifier_block *self,
		struct pt_regs *regs;
		int ret;

		if (!atomic_read(&num_counters))
		return NOTIFY_DONE;

		switch (cmd) {
		case DIE_NMI:
		case DIE_NMI_IPI: