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Zhou Chengming
75e8387685
When running perf on the ftrace:function tracepoint, there is a bug
which can be reproduced by:
perf record -e ftrace:function -a sleep 20 &
perf record -e ftrace:function ls
perf script
ls 10304 [005] 171.853235: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853237: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853239: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853240: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853242: ftrace:function:
__task_pid_nr_ns
ls 10304 [005] 171.853244: ftrace:function:
__task_pid_nr_ns
We can see that all the function traces are doubled.
The problem is caused by the inconsistency of the register
function perf_ftrace_event_register() with the probe function
perf_ftrace_function_call(). The former registers one probe
for every perf_event. And the latter handles all perf_events
on the current cpu. So when two perf_events on the current cpu,
the traces of them will be doubled.
So this patch adds an extra parameter "event" for perf_tp_event,
only send sample data to this event when it's not NULL.
Signed-off-by: Zhou Chengming <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>