perf tools: Add an option to multiplex counters in a single channel

Add an option to multiplex counters output in the channel of
the group leader, ie: the first counter opened:

	-M --multiplex

The effect is better serialized samples. This is especially
useful for tracepoint samples that need to be well serialized
for their post-processing.

Also make use of this option in 'perf sched'.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2009-09-14 08:57:15 +02:00 committed by Ingo Molnar
parent f977bb4937
commit d13025222c
2 changed files with 8 additions and 0 deletions

View file

@ -48,6 +48,7 @@ static int call_graph = 0;
static int inherit_stat = 0;
static int no_samples = 0;
static int sample_address = 0;
static int multiplex = 0;
static long samples;
static struct timeval last_read;
@ -485,6 +486,9 @@ try_again:
exit(-1);
}
if (multiplex && fd[nr_cpu][counter] != group_fd)
ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_SET_OUTPUT, group_fd);
ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
}
@ -681,6 +685,8 @@ static const struct option options[] = {
"Sample addresses"),
OPT_BOOLEAN('n', "no-samples", &no_samples,
"don't sample"),
OPT_BOOLEAN('M', "multiplex", &multiplex,
"multiplex counter output in a single channel"),
OPT_END()
};

View file

@ -1660,6 +1660,8 @@ static const char *record_args[] = {
"record",
"-a",
"-R",
"-M",
"-g",
"-c", "1",
"-e", "sched:sched_switch:r",
"-e", "sched:sched_stat_wait:r",