Re: [RESEND PATCH] perf sched map: re-annotate shortname if thread comm changed

[Du, Changbin]

On Fri, Mar 02, 2018 at 11:43:12AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, Feb 23, 2018 at 07:40:40PM +0800, changbin.du@xxxxxxxxx escreveu:
> > From: Changbin Du <changbin.du@xxxxxxxxx>
> > 
> > This is to show the real name of thread that created via fork-exec.
> > See below example for shortname *A0*.
> 
> Can you ellaborate a bit more and perhaps provide before and after
> outputs?
> 
> - Arnaldo
>
Arnaldo, please see below diff stat.
              *A0   80393.050639 secs A0 => perf:22368
          *.   A0   80393.050748 secs .  => swapper:0
           .  *.    80393.050887 secs
      *B0  .   .    80393.052735 secs B0 => rcu_sched:8
      *.   .   .    80393.052743 secs
       .  *C0  .    80393.056264 secs C0 => kworker/2:1H:287
       .  *A0  .    80393.056270 secs
       .  *D0  .    80393.056769 secs D0 => ksoftirqd/2:22
-      .  *A0  .    80393.056804 secs
+      .  *A0  .    80393.056804 secs A0 => pi:22368
       .  *.   .    80393.056854 secs


> > $ sudo ./perf sched map
> >               *A0   80393.050639 secs A0 => perf:22368
> >           *.   A0   80393.050748 secs .  => swapper:0
> >            .  *.    80393.050887 secs
> >       *B0  .   .    80393.052735 secs B0 => rcu_sched:8
> >       *.   .   .    80393.052743 secs
> >        .  *C0  .    80393.056264 secs C0 => kworker/2:1H:287
> >        .  *A0  .    80393.056270 secs
> >        .  *D0  .    80393.056769 secs D0 => ksoftirqd/2:22
> >        .  *A0  .    80393.056804 secs A0 => pi:22368
> >        .  *.   .    80393.056854 secs
> >       *B0  .   .    80393.060727 secs
> >       ...
> > 
> > Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> > ---
> >  tools/perf/builtin-sched.c | 4 +++-
> >  tools/perf/util/thread.c   | 1 +
> >  tools/perf/util/thread.h   | 1 +
> >  3 files changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> > index 83283fe..53bb8df 100644
> > --- a/tools/perf/builtin-sched.c
> > +++ b/tools/perf/builtin-sched.c
> > @@ -1580,7 +1580,7 @@ static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
> >  
> >  	timestamp__scnprintf_usec(timestamp, stimestamp, sizeof(stimestamp));
> >  	color_fprintf(stdout, color, "  %12s secs ", stimestamp);
> > -	if (new_shortname || (verbose > 0 && sched_in->tid)) {
> > +	if (new_shortname || sched_in->comm_changed || (verbose > 0 && sched_in->tid)) {
> >  		const char *pid_color = color;
> >  
> >  		if (thread__has_color(sched_in))
> > @@ -1588,6 +1588,8 @@ static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
> >  
> >  		color_fprintf(stdout, pid_color, "%s => %s:%d",
> >  		       sched_in->shortname, thread__comm_str(sched_in), sched_in->tid);
> > +
> > +		sched_in->comm_changed = false;
> >  	}
> >  
> >  	if (sched->map.comp && new_cpu)
> > diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> > index 68b65b1..c660fe6 100644
> > --- a/tools/perf/util/thread.c
> > +++ b/tools/perf/util/thread.c
> > @@ -212,6 +212,7 @@ static int ____thread__set_comm(struct thread *thread, const char *str,
> >  			unwind__flush_access(thread);
> >  	}
> >  
> > +	thread->comm_changed = true;
> >  	thread->comm_set = true;
> >  
> >  	return 0;
> > diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
> > index 40cfa36..b9a328b 100644
> > --- a/tools/perf/util/thread.h
> > +++ b/tools/perf/util/thread.h
> > @@ -27,6 +27,7 @@ struct thread {
> >  	int			cpu;
> >  	refcount_t		refcnt;
> >  	char			shortname[3];
> > +	bool			comm_changed;
> >  	bool			comm_set;
> >  	int			comm_len;
> >  	bool			dead; /* if set thread has exited */
> > -- 
> > 2.7.4

-- 
Thanks,
Changbin Du