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authorWang Nan <wangnan0@huawei.com>2016-05-23 07:13:38 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-05-23 18:22:00 -0300
commit65aea2338765da1a58cc26eeb84d72308492ecb5 (patch)
tree90998c4711d3349fbe05bc15ac60ece597c92f3c /tools
parent12f3ca4fc8e27aa602c9c3c717d755b1e8f7fd47 (diff)
downloadlinux-65aea2338765da1a58cc26eeb84d72308492ecb5.tar.gz
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>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/evlist.c27
-rw-r--r--tools/perf/util/evlist.h2
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);