From 957ea1fdbcdb909e1540f06f06f1a9ce6e696efa Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 3 Dec 2015 13:22:19 -0800 Subject: [PATCH] perf/x86: Remove warning for zero PEBS status The recent commit: 75f80859b130 ("perf/x86/intel/pebs: Robustify PEBS buffer drain") causes lots of warnings on different CPUs before Skylake when running PEBS intensive workloads. They can have a zero status field in the PEBS record when PEBS is racing with clearing of GLOBAl_STATUS. This also can cause hangs (it seems there are still problems with printk in NMI). Disable the warning, but still ignore the record. Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Link: http://lkml.kernel.org/r/1449177740-5422-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel_ds.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 5db1c7755548..0e3a9c73187d 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -1232,10 +1232,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) bit = find_first_bit((unsigned long *)&pebs_status, x86_pmu.max_pebs_events); - if (WARN(bit >= x86_pmu.max_pebs_events, - "PEBS record without PEBS event! status=%Lx pebs_enabled=%Lx active_mask=%Lx", - (unsigned long long)p->status, (unsigned long long)cpuc->pebs_enabled, - *(unsigned long long *)cpuc->active_mask)) + if (bit >= x86_pmu.max_pebs_events) continue; /* -- 2.20.1