From a4faf00d994c40e64f656805ac375c65e324eefb Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Fri, 25 Oct 2019 17:08:33 +0300 Subject: perf/aux: Allow using AUX data in perf samples AUX data can be used to annotate perf events such as performance counters or tracepoints/breakpoints by including it in sample records when PERF_SAMPLE_AUX flag is set. Such samples would be instrumental in debugging and profiling by providing, for example, a history of instruction flow leading up to the event's overflow. The implementation makes use of grouping an AUX event with all the events that wish to take samples of the AUX data, such that the former is the group leader. The samplees should also specify the desired size of the AUX sample via attr.aux_sample_size. AUX capable PMUs need to explicitly add support for sampling, because it relies on a new callback to take a snapshot of the buffer without touching the event states. Signed-off-by: Alexander Shishkin Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mark Rutland Cc: Namhyung Kim Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: adrian.hunter@intel.com Cc: mathieu.poirier@linaro.org Link: https://lkml.kernel.org/r/20191025140835.53665-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar --- include/uapi/linux/perf_event.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index bb7b271397a6..377d794d3105 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -141,8 +141,9 @@ enum perf_event_sample_format { PERF_SAMPLE_TRANSACTION = 1U << 17, PERF_SAMPLE_REGS_INTR = 1U << 18, PERF_SAMPLE_PHYS_ADDR = 1U << 19, + PERF_SAMPLE_AUX = 1U << 20, - PERF_SAMPLE_MAX = 1U << 20, /* non-ABI */ + PERF_SAMPLE_MAX = 1U << 21, /* non-ABI */ __PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63, /* non-ABI; internal use */ }; @@ -300,6 +301,7 @@ enum perf_event_read_format { /* add: sample_stack_user */ #define PERF_ATTR_SIZE_VER4 104 /* add: sample_regs_intr */ #define PERF_ATTR_SIZE_VER5 112 /* add: aux_watermark */ +#define PERF_ATTR_SIZE_VER6 120 /* add: aux_sample_size */ /* * Hardware event_id to monitor via a performance monitoring event: @@ -424,7 +426,9 @@ struct perf_event_attr { */ __u32 aux_watermark; __u16 sample_max_stack; - __u16 __reserved_2; /* align to __u64 */ + __u16 __reserved_2; + __u32 aux_sample_size; + __u32 __reserved_3; }; /* @@ -864,6 +868,8 @@ enum perf_event_type { * { u64 abi; # enum perf_sample_regs_abi * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR * { u64 phys_addr;} && PERF_SAMPLE_PHYS_ADDR + * { u64 size; + * char data[size]; } && PERF_SAMPLE_AUX * }; */ PERF_RECORD_SAMPLE = 9, -- cgit v1.2.3