Re: [PATCH] perf tools: Use tid for finding thread

From: Stephane Eranian
Date: Wed May 07 2014 - 08:01:27 EST


On Wed, May 7, 2014 at 4:26 AM, Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> I believe that passing pid (instead of tid) as the 3rd arg of the
> machine__find*_thread() was to find a main thread so that it can
> search proper map group for symbols. However with the map sharing
> patch applied, it now can do it in any thread.
>
Your patch makes the code more meaningful for sure.
The pid, pid looked like a bug to me at first, but then I realized,
that yes, it is
look for the main thread.

Acked-by: Stephane Eranian <eranian@xxxxxxxxxx>

>
> It fixes a bug when each thread has different name, it only reports a
> main thread for samples in other threads.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Stephane Eranian <eranian@xxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/builtin-inject.c | 2 +-
> tools/perf/builtin-kmem.c | 2 +-
> tools/perf/tests/code-reading.c | 2 +-
> tools/perf/util/build-id.c | 2 +-
> tools/perf/util/event.c | 2 +-
> 5 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
> index 3a7387551369..6a3af0013d68 100644
> --- a/tools/perf/builtin-inject.c
> +++ b/tools/perf/builtin-inject.c
> @@ -209,7 +209,7 @@ static int perf_event__inject_buildid(struct perf_tool *tool,
>
> cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
>
> - thread = machine__findnew_thread(machine, sample->pid, sample->pid);
> + thread = machine__findnew_thread(machine, sample->pid, sample->tid);
> if (thread == NULL) {
> pr_err("problem processing %d event, skipping it.\n",
> event->header.type);
> diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
> index f91fa4376f4b..bef3376bfaf3 100644
> --- a/tools/perf/builtin-kmem.c
> +++ b/tools/perf/builtin-kmem.c
> @@ -235,7 +235,7 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
> struct machine *machine)
> {
> struct thread *thread = machine__findnew_thread(machine, sample->pid,
> - sample->pid);
> + sample->tid);
>
> if (thread == NULL) {
> pr_debug("problem processing %d event, skipping it.\n",
> diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
> index adf3de3e38d6..67f2d6323558 100644
> --- a/tools/perf/tests/code-reading.c
> +++ b/tools/perf/tests/code-reading.c
> @@ -256,7 +256,7 @@ static int process_sample_event(struct machine *machine,
> return -1;
> }
>
> - thread = machine__findnew_thread(machine, sample.pid, sample.pid);
> + thread = machine__findnew_thread(machine, sample.pid, sample.tid);
> if (!thread) {
> pr_debug("machine__findnew_thread failed\n");
> return -1;
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 6baabe63182b..a904a4cfe7d3 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -25,7 +25,7 @@ int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
> struct addr_location al;
> u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
> struct thread *thread = machine__findnew_thread(machine, sample->pid,
> - sample->pid);
> + sample->tid);
>
> if (thread == NULL) {
> pr_err("problem processing %d event, skipping it.\n",
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index dbcaea1a8180..65795b835b39 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -788,7 +788,7 @@ int perf_event__preprocess_sample(const union perf_event *event,
> {
> u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
> struct thread *thread = machine__findnew_thread(machine, sample->pid,
> - sample->pid);
> + sample->tid);
>
> if (thread == NULL)
> return -1;
> --
> 1.9.2
>
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