From 8b412664d0a487c2e16ac43f4fcede346df33254 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 19:59:05 +0200 Subject: [PATCH] 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 LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/builtin-record.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 5f3127e7a615..2459e5a22ed8 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -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. */ -- 2.20.1