From: Arnaldo Carvalho de Melo <[email protected]> The evsel->idx field is used mainly to access the right bucket in per-event arrays such as the annotation ones, but also to set evsel->tracking, that in turn will decide what of the events will ask for PERF_RECORD_{MMAP,COMM,EXEC} to be generated, i.e. which perf_event_attr will have its mmap, etc fields set.
When we were adding the "dummy" event using perf_evlist__add_dummy() we were not setting it correctly, which could result in multiple tracking events. Now that I'll try using a dummy event to be the tracking one when using 'perf record --delay', i.e. when we process the --delay setting we may already have the evlist set up, like with: perf record -e cycles,instructions --delay 1000 ./workload We will need to add a "dummy" event, then reset evsel->tracking for the first event, "cycles", and set it instead to the dummy one, and also setting its attr.enable_on_exec, so that we get the PERF_RECORD_MMAP, etc metadata events while waiting to enable the explicitely requested events, so lets get this straight and set the right evsel->idx. Cc: Adrian Hunter <[email protected]> Cc: Bram Stolk <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/evlist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index c6c891e154a6..ccb749f9a83f 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -257,7 +257,7 @@ int perf_evlist__add_dummy(struct perf_evlist *evlist) .config = PERF_COUNT_SW_DUMMY, .size = sizeof(attr), /* to capture ABI version */ }; - struct perf_evsel *evsel = perf_evsel__new(&attr); + struct perf_evsel *evsel = perf_evsel__new_idx(&attr, evlist->nr_entries); if (evsel == NULL) return -ENOMEM; -- 2.13.6
