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authorDavid Ahern <dsahern@gmail.com>2011-08-25 10:17:55 -0600
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-09-23 14:36:53 -0300
commit764e16a30a77a9c8346fbae6615e7c818ce9d00f (patch)
tree584d41f3bd611dfbf1345396b47629971fa035fd /tools/perf/util
parent694bf407b06113f5e0f71764756f11903126fec0 (diff)
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')
-rw-r--r--tools/perf/util/evlist.c13
-rw-r--r--tools/perf/util/evlist.h1
2 files changed, 14 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index c12bd476c6f..72e9f4886b6 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;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index ce85ae9ae57..f3491500274 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -54,6 +54,7 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite);
void perf_evlist__munmap(struct perf_evlist *evlist);
void perf_evlist__disable(struct perf_evlist *evlist);
+void perf_evlist__enable(struct perf_evlist *evlist);
static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
struct cpu_map *cpus,