Before this patch we can see very large time in the events before
bpf-output event. For example:
# ./perf trace -vv -T --ev sched:sched_switch \
--ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:channel.event=evt/ \
usleep 10
...
18446744073709.551 (18446564645918.480 ms): usleep/4157 nanosleep(rqtp:
0x7ffd3f0dc4e0 ) ...
18446744073709.551 ( ): evt:Raise a BPF event!..)
179427791.076 ( ): perf_bpf_probe:func_begin:(ffffffff810eb9a0))
179427791.081 ( ): sched:sched_switch:usleep:4157 [120] S ==>
swapper/2:0 [120])
...
We can also see the differences between bpf-output events and
breakpoint events:
For bpf output event:
sample_type IP|TID|RAW|IDENTIFIER
For tracepoint events:
sample_type IP|TID|TIME|CPU|PERIOD|RAW|IDENTIFIER
This patch fix this differences by adding more sample type for
bpf-output events.
After this patch:
# ./perf trace -vv -T --ev sched:sched_switch \
--ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:channel.event=evt/ \
usleep 10
...
179877370.878 ( 0.003 ms): usleep/5336 nanosleep(rqtp: 0x7ffff866c450
) ...
179877370.878 ( ): evt:Raise a BPF event!..)
179877370.878 ( ): perf_bpf_probe:func_begin:(ffffffff810eb9a0))
179877370.882 ( ): sched:sched_switch:usleep:5336 [120] S ==>
swapper/4:0 [120])
179877370.945 ( ): evt:Raise a BPF event!..)
...
# ./perf trace -vv -T --ev sched:sched_switch \
--ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:channel.event=evt/ \
usleep 10 2>&1 | grep sample_type
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
sample_type IP|TID|TIME|ID|CPU|PERIOD|RAW
The 'IDENTIFIER' is not required because all events have the
same sample_type.
Signed-off-by: Wang Nan <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Milian Wolff <[email protected]>
Cc: Namhyung Kim <[email protected]>
---
tools/perf/util/evsel.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 738ce22..3fd7c2c 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -226,7 +226,8 @@ struct perf_evsel *perf_evsel__new_idx(struct
perf_event_attr *attr, int idx)
perf_evsel__init(evsel, attr, idx);
if (perf_evsel__is_bpf_output(evsel)) {
- evsel->attr.sample_type |= PERF_SAMPLE_RAW;
+ evsel->attr.sample_type |= (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
+ PERF_SAMPLE_CPU |
PERF_SAMPLE_PERIOD),
evsel->attr.sample_period = 1;
}
--
1.8.3.4
