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Subject[PATCH 1/2] x86, perf: Remove warning for zero PEBS status
Date
From: Andi Kleen <ak@linux.intel.com>

The recent change 75f80859b1 (... 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 <ak@linux.intel.com>
---
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 7f11784..da294de 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -1237,10 +1237,7 @@ 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;

/*
--
2.4.3


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