Commit 5e1c81d9 authored May 13, 2012 by David Ahern Committed by Arnaldo Carvalho de Melo May 18, 2012

perf evsel: Create events initially disabled -- again



764e16a3 changed perf-record to create events disabled by default and
enable them once perf initializations are done. This setting was dropped
by 0f82ebc4. Now perf events are once again generated during perf's
initialization phase (e.g., generating maps).

As an example, perf opens a lot of files at startup. Unpatched:

perf record -e syscalls:sys_enter_open -ga -fo /tmp/perf.data -- sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.087 MB /tmp/perf.data (~3798 samples) ]

Using perf-script to look at the samples shows the perf command generating
563 of the 566 total events.

Patched:

perf record -e syscalls:sys_enter_open -ga -fo /tmp/perf.data -- sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.028 MB /tmp/perf.data (~1206 samples) ]

Using perf-script to look at the samples does not show perf command.

Signed-off-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1336968088-11531-1-git-send-email-dsahern@gmail.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 16ee6576

tools/perf/util/evsel.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -70,6 +70,7 @@ void perf_evsel__config(struct perf_evsel evsel, struct perf_record_opts opts,
		struct perf_event_attr *attr = &evsel->attr;
		int track = !evsel->idx; /* only the first counter needs these */

		attr->disabled = 1;
		attr->sample_id_all = opts->sample_id_all_missing ? 0 : 1;
		attr->inherit = !opts->no_inherit;
		attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED \|
		@@ -138,7 +139,6 @@ void perf_evsel__config(struct perf_evsel evsel, struct perf_record_opts opts,

		if (perf_target__none(&opts->target) &&
		(!opts->group \|\| evsel == first)) {
		attr->disabled = 1;
		attr->enable_on_exec = 1;
		}
		}

Admin message