Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [PATCH v3 01/11] perf tools: Add API to pause/resume a evlist | Date | Mon, 23 May 2016 07:13:38 +0000 |
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perf_evlist__toggle_{pause,resume}() are introduced to pause/resume events in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following commits use them to ensure overwrite ring buffer is paused before reading.
Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: He Kuang <hekuang@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/util/evlist.c | 32 ++++++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 2 ++ 2 files changed, 34 insertions(+)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 1a370db..9303525 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -679,6 +679,38 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, return NULL; } +static int perf_evlist__set_paused(struct perf_evlist *evlist, bool pause) +{ + int i; + + for (i = 0; i < evlist->nr_mmaps; i++) { + int fd = evlist->mmap[i].fd; + int err; + + if (fd < 0) + continue; + err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, + pause ? 1 : 0); + if (err) { + err = (errno == 0 ? -EINVAL : -errno); + pr_err("Unable to pause output on %d: %s\n", + fd, strerror(-err)); + return err; + } + } + return 0; +} + +int perf_evlist__pause(struct perf_evlist *evlist) +{ + return perf_evlist__set_paused(evlist, true); +} + +int perf_evlist__resume(struct perf_evlist *evlist) +{ + return perf_evlist__set_paused(evlist, false); +} + /* When check_messup is true, 'end' must points to a good entry */ static union perf_event * perf_mmap__read(struct perf_mmap *md, bool check_messup, u64 start, diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 0d165b1..97090b7 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -136,6 +136,8 @@ void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx); void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); +int perf_evlist__pause(struct perf_evlist *evlist); +int perf_evlist__resume(struct perf_evlist *evlist); int perf_evlist__open(struct perf_evlist *evlist); void perf_evlist__close(struct perf_evlist *evlist); -- 1.8.3.4
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