perf: Process comm events by tid
authorFrederic Weisbecker <fweisbec@gmail.com>
Mon, 31 May 2010 21:38:44 +0000 (23:38 +0200)
committerFrederic Weisbecker <fweisbec@gmail.com>
Mon, 31 May 2010 21:59:50 +0000 (23:59 +0200)
commit13eb04fdbeb9d21dfe4696630daefe18ef6a1a84
tree47edb43ab193dfc99227f760ee70bb9c393d14c4
parent546cf44a1b507c1cbb5cf42bbe6169780567f36f
perf: Process comm events by tid

When we synthetize the existing running tasks though procfs,
we walk through every threads of a process, queuing one comm
events per tid.

But then on report time, event__process_comm() only creates and
sets the comm on a per process granularity. This is the right
thing for comm events that came from the kernel, as they are
only created on exec. Sub-threads then inherit their comm
from fork events. But that doesn't work with our synthetized
comm events taken from procfs informations as the per thread
granularity is done on comm events directly there.

Hence we need event__process_comm() to work with the tid rather
than the pid. It won't change anything for comm events coming
from the kernel but this will fix the synthetized ones.

Before:

$ ./perf report -D | grep COMM | grep firefox

0x2c7b8 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c7d0 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c7e8 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c800 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c818 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c830 [0x18]: PERF_RECORD_COMM: firefox:5297

After:
$ ./perf report -D | grep COMM | grep firefox

0x2c7b8 [0x18]: PERF_RECORD_COMM: firefox:5297
0x2c7d0 [0x18]: PERF_RECORD_COMM: firefox:5299
0x2c7e8 [0x18]: PERF_RECORD_COMM: firefox:5300
0x2c800 [0x18]: PERF_RECORD_COMM: firefox:5308
0x2c818 [0x18]: PERF_RECORD_COMM: firefox:5309
0x2c830 [0x18]: PERF_RECORD_COMM: firefox:5312

This fixes various unresolved pid on perf sched.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
tools/perf/util/event.c