Messages in this thread Patch in this message | | | Date | Fri, 20 May 2016 15:05:07 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2 03/13] perf tools: Add API to pause a evlist |
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Em Fri, May 20, 2016 at 04:38:25PM +0000, Wang Nan escreveu: > perf_evlist__toggle_paused() is introduced to pause/resume events > in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following > commits use perf_evlist__toggle_paused() to ensure overwrite > ring buffer is paused before reading. > +{
int perf_evlist__toggle_paused(struct perf_evlist *evlist, bool pause)
Humm, toggle means, 1 -> 0 or 0 -> 1, not set(n), i.e. you either call this:
int perf_evlist__toggle_paused(struct perf_evlist *evlist)
and keep an evsel->paused that starts with false and then you, in this function, use:
err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, evsel->pause ? 1 : 0); if (!err) evsel->paused = !evsel->paused;
Or:
int perf_evlist__set_paused(struct perf_evlist *evlist, bool pause)
and do as you did below.
And you could do, to make it shorter, more intuitive:
static inline int perf_evlist__pause(struct perf_evlist *evlist) { return perf_evlist__set_paused(evlist, true); }
static inline int perf_evlist__continue(struct perf_evlist *evlist) { return perf_evlist__set_paused(evlist, false); }
I applied the first two patches.
- Arnaldo > 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 | 22 ++++++++++++++++++++++ > tools/perf/util/evlist.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index 1a370db..f4bb8be 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -679,6 +679,28 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, > return NULL; > } > > +int perf_evlist__toggle_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; > +} > + > /* 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..13234dc 100644 > --- a/tools/perf/util/evlist.h > +++ b/tools/perf/util/evlist.h > @@ -136,6 +136,7 @@ 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__toggle_paused(struct perf_evlist *evlist, bool pause); > int perf_evlist__open(struct perf_evlist *evlist); > void perf_evlist__close(struct perf_evlist *evlist); > > -- > 1.8.3.4
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