Re: [PATCH] perf util: Use target->per_thread and target->system_wide flags

[Jin, Yao]

On 1/23/2018 7:56 AM, Mathieu Poirier wrote:
> On 22 January 2018 at 15:15, Jin Yao <yao.jin@xxxxxxxxxxxxxxx> wrote:
> > Mathieu Poirier reports issue in commit ("73c0ca1eee3d perf thread_map:
> > Enumerate all threads from /proc") that it has negative impact on
> > 'perf record --per-thread'. It has the effect of creating a kernel event
> > for each thread in the system for 'perf record --per-thread'.
> >
> > Mathieu Poirier's patch ("perf util: Do not reuse target->per_thread flag")
> > can fix this issue by creating a new target->all_threads flag.
> >
> > This patch is based on Mathieu Poirier's patch but it doesn't use a new
> > target->all_threads flag. This patch just uses 'target->per_thread &&
> > target->system_wide' as a condition to check for all threads case.
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/util/evlist.c     | 2 +-
> >   tools/perf/util/thread_map.c | 4 ++--
> >   tools/perf/util/thread_map.h | 2 +-
> >   3 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> > index 120efd8..9dff74a 100644
> > --- a/tools/perf/util/evlist.c
> > +++ b/tools/perf/util/evlist.c
> > @@ -1106,7 +1106,7 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
> >          struct thread_map *threads;
> >
> >          threads = thread_map__new_str(target->pid, target->tid, target->uid,
> > -                                     target->per_thread);
> > +                                     target->per_thread && target->system_wide);
> >
> >          if (!threads)
> >                  return -1;
> > diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
> > index 3e1038f..729dad8 100644
> > --- a/tools/perf/util/thread_map.c
> > +++ b/tools/perf/util/thread_map.c
> > @@ -323,7 +323,7 @@ struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
> >   }
> >
> >   struct thread_map *thread_map__new_str(const char *pid, const char *tid,
> > -                                      uid_t uid, bool per_thread)
> > +                                      uid_t uid, bool all_threads)
> >   {
> >          if (pid)
> >                  return thread_map__new_by_pid_str(pid);
> > @@ -331,7 +331,7 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid,
> >          if (!tid && uid != UINT_MAX)
> >                  return thread_map__new_by_uid(uid);
> >
> > -       if (per_thread)
> > +       if (all_threads)
> >                  return thread_map__new_all_cpus();
> >
> >          return thread_map__new_by_tid_str(tid);
> > diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
> > index 0a806b9..5ec91cf 100644
> > --- a/tools/perf/util/thread_map.h
> > +++ b/tools/perf/util/thread_map.h
> > @@ -31,7 +31,7 @@ struct thread_map *thread_map__get(struct thread_map *map);
> >   void thread_map__put(struct thread_map *map);
> >
> >   struct thread_map *thread_map__new_str(const char *pid,
> > -               const char *tid, uid_t uid, bool per_thread);
> > +               const char *tid, uid_t uid, bool all_threads);
> >
> >   struct thread_map *thread_map__new_by_tid_str(const char *tid_str);
>
> Reviewed-and-tested-by: Mathieu Poirier "mathieu.poirier@xxxxxxxxxx"

Thanks a lot for reviewing the patch.

Thanks
Jin Yao