| Message ID | 1491495496-1524-5-git-send-email-will.deacon@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add support for the ARMv8.2 Statistical Profiling Extension | expand |
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)
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(+) -- 2.1.4