From e2b5abe0c82b45980b95ead22678861a2013c0df Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 4 Apr 2012 19:32:27 +0200 Subject: [PATCH] perf evlist: Use PERF_EVENT_IOC_ID perf ioctl to read event id Changing the way we retrieve the event ID. Instead of parsing out the ID out of the read data, using the PERF_EVENT_IOC_ID ioctl. Keeping the old way in place to support kernels without PERF_EVENT_IOC_ID ioctl support. This will be useful for retrieving the event ID for events with PERF_FORMAT_GROUP read format set, where it's impossible to get correct event id out of the read call data. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Corey Ashford Cc: Frederic Weisbecker Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-psgb4n7kte8e6tfenbe7nj2h@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 42ea4e947eb8..0d3b73996255 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -302,6 +302,17 @@ static int perf_evlist__id_add_fd(struct perf_evlist *evlist, { u64 read_data[4] = { 0, }; int id_idx = 1; /* The first entry is the counter value */ + u64 id; + int ret; + + ret = ioctl(fd, PERF_EVENT_IOC_ID, &id); + if (!ret) + goto add; + + if (errno != ENOTTY) + return -1; + + /* Legacy way to get event id.. All hail to old kernels! */ if (!(evsel->attr.read_format & PERF_FORMAT_ID) || read(fd, &read_data, sizeof(read_data)) == -1) @@ -312,7 +323,10 @@ static int perf_evlist__id_add_fd(struct perf_evlist *evlist, if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) ++id_idx; - perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]); + id = read_data[id_idx]; + + add: + perf_evlist__id_add(evlist, evsel, cpu, thread, id); return 0; } -- 2.20.1