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[PATCH v2 4/6] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples

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The ARM SPE architecture permits an implementation to ignore a sample
if the sample is due to be taken whilst another sample is already being
produced. In this case, it is desirable to report the collision to
userspace, as they may want to lower the sample period.

This patch adds a PERF_AUX_FLAG_COLLISION flag, so that such events can
be relayed to userspace.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 include/uapi/linux/perf_event.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index c66a485a24ac..f4e3a21cade5 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -885,6 +885,7 @@ enum perf_callchain_context {
  */
 #define PERF_AUX_FLAG_TRUNCATED		0x01	/* record was truncated to fit */
 #define PERF_AUX_FLAG_OVERWRITE		0x02	/* snapshot from overwrite mode */
+#define PERF_AUX_FLAG_COLLISION		0x08	/* sample collided with another */
 
 #define PERF_FLAG_FD_NO_GROUP		(1UL << 0)
 #define PERF_FLAG_FD_OUTPUT		(1UL << 1)
-- 
2.1.4

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[PATCH v2 0/6] Add support for the ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200
  [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200
    Re: [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2  Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-04-06 20:40 +0200
      Re: [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2 Statistical  Profiling Extension Mark Rutland <mark.rutland@arm.com> - 2017-04-06 20:50 +0200
        Re: [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2  Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-04-07 13:00 +0200
          Re: [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2 Statistical  Profiling Extension Mark Rutland <mark.rutland@arm.com> - 2017-04-07 13:40 +0200
            Re: [PATCH v2 5/6] drivers/perf: Add support for ARMv8.2  Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-04-07 17:30 +0200
  [PATCH v2 2/6] genirq: export irq_get_percpu_devid_partition to modules Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200
  [PATCH v2 1/6] perf/core: Keep AUX flags in the output handle Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200
  [PATCH v2 4/6] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200
  [PATCH v2 6/6] dt-bindings: Document devicetree binding for ARM SPE Will Deacon <will.deacon@arm.com> - 2017-04-06 18:20 +0200

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