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Commit 8d330919 authored by Lin Ming's avatar Lin Ming Committed by Ingo Molnar
Browse files

perf, x86, Pentium4: Clear the P4_CCCR_FORCE_OVF flag 



If on Pentium4 CPUs the FORCE_OVF flag is set then an NMI happens
on every event, which can generate a flood of NMIs. Clear it.

Reported-by: default avatarVince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: default avatarLin Ming <ming.m.lin@intel.com>
Signed-off-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 151772db

arch/x86/kernel/cpu/perf_event_p4.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -497,6 +497,8 @@ static int p4_hw_config(struct perf_event *event) 
		event->hw.config |= event->attr.config &

		event->hw.config |= event->attr.config &

			(p4_config_pack_escr(P4_ESCR_MASK_HT) |

			(p4_config_pack_escr(P4_ESCR_MASK_HT) |

			 p4_config_pack_cccr(P4_CCCR_MASK_HT | P4_CCCR_RESERVED));

			 p4_config_pack_cccr(P4_CCCR_MASK_HT | P4_CCCR_RESERVED));



		event->hw.config &= ~P4_CCCR_FORCE_OVF;

	}

	}





	rc = x86_setup_perfctr(event);

	rc = x86_setup_perfctr(event);