perf evlist: Add API to pause/resume (65aea233) · Commits · 戴 / test

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>

tools/perf/util/evlist.c

+27 −0

Original line number	Diff line number	Diff line
		@@ -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,

tools/perf/util/evlist.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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);

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