diff options
| author | David Ahern <dsahern@gmail.com> | 2011-08-25 10:17:55 -0600 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2011-09-23 14:36:53 -0300 |
| commit | 764e16a30a77a9c8346fbae6615e7c818ce9d00f (patch) | |
| tree | 584d41f3bd611dfbf1345396b47629971fa035fd /tools/perf/util/evlist.c | |
| parent | 694bf407b06113f5e0f71764756f11903126fec0 (diff) | |
| download | op-kernel-dev-764e16a30a77a9c8346fbae6615e7c818ce9d00f.zip op-kernel-dev-764e16a30a77a9c8346fbae6615e7c818ce9d00f.tar.gz | |
perf record: Create events initially disabled and enable after init
perf-record currently creates events enabled. When doing a system wide
collection (-a arg) this causes data collection for perf's
initialization activities -- eg., perf_event__synthesize_threads().
For some events (e.g., context switch S/W event or tracepoints like
syscalls) perf's initialization causes a lot of events to be captured
frequently generating "Check IO/CPU overload!" warnings on larger
systems (e.g., 2 socket, quad core, hyperthreading).
perf's initialization phase can be skipped by creating events
disabled and then enabling them once the initialization is done.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1314289075-14706-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evlist.c')
| -rw-r--r-- | tools/perf/util/evlist.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index c12bd47..72e9f48 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -113,6 +113,19 @@ void perf_evlist__disable(struct perf_evlist *evlist) } } +void perf_evlist__enable(struct perf_evlist *evlist) +{ + int cpu, thread; + struct perf_evsel *pos; + + for (cpu = 0; cpu < evlist->cpus->nr; cpu++) { + list_for_each_entry(pos, &evlist->entries, node) { + for (thread = 0; thread < evlist->threads->nr; thread++) + ioctl(FD(pos, cpu, thread), PERF_EVENT_IOC_ENABLE); + } + } +} + int perf_evlist__alloc_pollfd(struct perf_evlist *evlist) { int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries; |
