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| author |   Zhou Chengming <zhouchengming1@huawei.com> | 2017-08-25 21:49:37 +0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-08-29 13:29:29 +0200 |
| commit | 75e8387685f6c65feb195a4556110b58f852b848 (patch) | |
| tree | 1c8f8318f1fe76197a2a0d2fcfc53992b1855b30 /include/linux/trace_events.h | |
| parent | perf/core: Fix potential double-fetch bug (diff) | |
| download | linux-dev-75e8387685f6c65feb195a4556110b58f852b848.tar.xz linux-dev-75e8387685f6c65feb195a4556110b58f852b848.zip | |
perf/ftrace: Fix double traces of perf on ftrace:function
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 <zhouchengming1@huawei.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/trace_events.h')
| -rw-r--r-- | include/linux/trace_events.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 536c80ff7ad9..5012b524283d 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -508,9 +508,9 @@ void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, static inline void perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type, u64 count, struct pt_regs *regs, void *head, - struct task_struct *task) + struct task_struct *task, struct perf_event *event) { - perf_tp_event(type, count, raw_data, size, regs, head, rctx, task); + perf_tp_event(type, count, raw_data, size, regs, head, rctx, task, event); } #endif |