From 57e7986ed142417498155ebcd5eaf617ac37136d Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@samba.org>
Date: Tue, 30 Jun 2009 16:07:19 +1000
Subject: perf_counter: Provide a way to enable counters on exec
This provides a way to mark a counter to be enabled on the next
exec. This is useful for measuring the total activity of a
program without including overhead from the process that
launches it.
This also changes the perf stat command to use this new
facility.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19017.43927.838745.689203@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
tools/perf/builtin-stat.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
(limited to 'tools/perf')
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 201ef2367dc..2e03524a1de 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -116,8 +116,9 @@ static void create_perf_stat_counter(int counter, int pid)
fd[cpu][counter], strerror(errno));
}
} else {
- attr->inherit = inherit;
- attr->disabled = 1;
+ attr->inherit = inherit;
+ attr->disabled = 1;
+ attr->enable_on_exec = 1;
fd[0][counter] = sys_perf_counter_open(attr, pid, -1, -1, 0);
if (fd[0][counter] < 0 && verbose)
@@ -262,7 +263,6 @@ static int run_perf_stat(int argc, const char **argv)
* Enable counters and exec the command:
*/
t0 = rdclock();
- prctl(PR_TASK_PERF_COUNTERS_ENABLE);
close(go_pipe[1]);
wait(&status);
--
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