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| author | Wang Nan <wangnan0@huawei.com> | 2016-05-23 09:13:38 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-23 23:22:00 +0200 |
| commit | 65aea2338765da1a58cc26eeb84d72308492ecb5 (patch) | |
| tree | 90998c4711d3349fbe05bc15ac60ece597c92f3c | |
| parent | perf trace: Use the ptr->name beautifier as default for "filename" args (diff) | |
| download | linux-65aea2338765da1a58cc26eeb84d72308492ecb5.tar.xz linux-65aea2338765da1a58cc26eeb84d72308492ecb5.zip | |
perf evlist: Add API to pause/resume
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>
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
Link: http://lkml.kernel.org/r/1463987628-163563-2-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
[ Return -1, like all other ioctl() usage in evlist.c, rename 'pause'
arg to avoid breaking the build on ubuntu 12.04 and other old systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/evlist.c | 27 | ||||
| -rw-r--r-- | tools/perf/util/evlist.h | 2 |
2 files changed, 29 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 1a370db02a8c..904523a2be90 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -679,6 +679,33 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, return NULL; } +static int perf_evlist__set_paused(struct perf_evlist *evlist, bool value) +{ + 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, value ? 1 : 0); + if (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 0d165b1d8f77..97090b70976d 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); |