From d8020bee1d0caa90e7b9d6f39ac1fdfaaee7f67f Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sun, 10 May 2015 12:22:45 -0700 Subject: [PATCH] perf/x86/intel: Handle new arch perfmon v4 status bits ArchPerfmon v4 has some new status bits in GLOBAL_STATUS. These need to be ignored when deciding whether a NMI was an NMI, to avoid eating all NMIs when they stay set, see: b292d7a10487 ("perf/x86/intel: ignore CondChgd bit to avoid false NMI handling") This patch ignores the new ASIF bit, which indicates that SGX interfered with the PMU, and also the new LBR freezing bits, which are set when the LBRs get frozen, plus the existing CondChange (set by JTAG debuggers and some buggy BIOSes) Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-8-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index cb112bffcf70..52c9ded70f6c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1611,13 +1611,14 @@ again: intel_pmu_lbr_read(); /* - * CondChgd bit 63 doesn't mean any overflow status. Ignore - * and clear the bit. + * Ignore a range of extra bits in status that do not indicate + * overflow by themselves. */ - if (__test_and_clear_bit(63, (unsigned long *)&status)) { - if (!status) - goto done; - } + status &= ~(GLOBAL_STATUS_COND_CHG | + GLOBAL_STATUS_ASIF | + GLOBAL_STATUS_LBRS_FROZEN); + if (!status) + goto done; /* * PEBS overflow sets bit 62 in the global status register -- 2.20.1