lkml.org 
[lkml]   [2017]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 3/7] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples
Date
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 140ae638cfd6..7ca1b22ea417 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -941,6 +941,7 @@ 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_PARTIAL 0x04 /* record contains gaps */
+#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
\
 
 \ /
  Last update: 2017-09-28 16:10    [W:0.082 / U:11.180 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site