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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>
This commit is contained in:
Peter Zijlstra 2009-09-17 19:59:05 +02:00 committed by Ingo Molnar
parent 2667de81f3
commit 8b412664d0
1 changed files with 12 additions and 1 deletions
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13
tools/perf/builtin-record.c
View File

@ -524,6 +524,7 @@ static int __cmd_record(int argc, const char **argv)
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 @@ static int __cmd_record(int argc, const char **argv)
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.
*/