Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 03/11] perf tool: Use PERF_EVENT_IOC_ID perf ioctl to read event id | Date | Sat, 20 Oct 2012 16:33:11 +0200 |
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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.
Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/evlist.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 561bdfb..ef13aab 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -290,19 +290,33 @@ static int perf_evlist__id_add_fd(struct perf_evlist *evlist, struct perf_evsel *evsel, int cpu, int thread, int fd) { - u64 read_data[4] = { 0, }; - int id_idx = 1; /* The first entry is the counter value */ + u64 id; + int ret; - if (!(evsel->attr.read_format & PERF_FORMAT_ID) || - read(fd, &read_data, sizeof(read_data)) == -1) - return -1; + ret = ioctl(fd, PERF_EVENT_IOC_ID, &id); + if (!ret) + goto add; + + /* Legacy way to get event id.. All hail to old kernels! */ + if (errno == ENOTTY) { + u64 read_data[4] = { 0, }; + int id_idx = 1; /* The first entry is the counter value */ + + if (!(evsel->attr.read_format & PERF_FORMAT_ID) || + read(fd, &read_data, sizeof(read_data)) == -1) + return -1; - if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) - ++id_idx; - if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) - ++id_idx; + if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + ++id_idx; + if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + ++id_idx; + + id = read_data[id_idx]; + } else if (errno) + return -1; - perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]); + add: + perf_evlist__id_add(evlist, evsel, cpu, thread, id); return 0; } -- 1.7.11.4
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