perf record: Disable profiling before draining the buffer
I noticed that perf-record continues profiling itself after the
child terminated and we're draining the buffer.
This can cause a _lot_ of overhead with --all recording - we keep
and keep recording, which produces new and new events.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 5f3127e..2459e5a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -524,6 +524,7 @@
pid_t pid = 0;
int flags;
int ret;
+ unsigned long waking = 0;
page_size = sysconf(_SC_PAGE_SIZE);
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
@@ -634,10 +635,20 @@
if (hits == samples) {
if (done)
break;
- ret = poll(event_array, nr_poll, 100);
+ ret = poll(event_array, nr_poll, -1);
+ waking++;
+ }
+
+ if (done) {
+ for (i = 0; i < nr_cpu; i++) {
+ for (counter = 0; counter < nr_counters; counter++)
+ ioctl(fd[i][counter], PERF_COUNTER_IOC_DISABLE);
+ }
}
}
+ fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
+
/*
* Approximate RIP event size: 24 bytes.
*/