Commit-ID: 65aea2338765da1a58cc26eeb84d72308492ecb5
Gitweb: http://git.kernel.org/tip/65aea2338765da1a58cc26eeb84d72308492ecb5
Author: Wang Nan <wangnan0@xxxxxxxxxx>
AuthorDate: Mon, 23 May 2016 07:13:38 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 23 May 2016 18:22:00 -0300
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@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1463987628-163563-2-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
---
tools/perf/util/evlist.c | 27 +++++++++++++++++++++++++++
tools/perf/util/evlist.h | 2 ++
2 files changed, 29 insertions(+)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 1a370db..904523a 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 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);
--
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