[PATCH 1/3] perf tools: Add evlist__disable_evsel/evlist__enable_evsel

Jiri Olsa
2020-12-06T17:06:29Z

Adding interface to enable/disable single event in the
evlist based on its name. It will be used later in new
control enable/disable interface.

Keeping the evlist::enabled true when one or more events
are enabled so the toggle can work properly and toggle
evlist to disabled state.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/evlist.c | 69 ++++++++++++++++++++++++++++++++++++++--
tools/perf/util/evlist.h | 2 ++
2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 493819173a8e..70aff26612a9 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -370,7 +370,30 @@ bool evsel__cpu_iter_skip(struct evsel *ev, int cpu)
return true;
}

-void evlist__disable(struct evlist *evlist)
+static int evsel__strcmp(struct evsel *pos, char *evsel_name)
+{
+ if (!evsel_name)
+ return 0;
+ if (evsel__is_dummy_event(pos))
+ return 1;
+ return strcmp(pos->name, evsel_name);
+}
+
+static int evlist__is_enabled(struct evlist *evlist)
+{
+ struct evsel *pos;
+
+ evlist__for_each_entry(evlist, pos) {
+ if (!evsel__is_group_leader(pos) || !pos->core.fd)
+ continue;
+ /* If at least one event is enabled, evlist is enabled. */
+ if (!pos->disabled)
+ return true;
+ }
+ return false;
+}
+
+static void __evlist__disable(struct evlist *evlist, char *evsel_name)
{
struct evsel *pos;
struct affinity affinity;
@@ -386,6 +409,8 @@ void evlist__disable(struct evlist *evlist)
affinity__set(&affinity, cpu);

evlist__for_each_entry(evlist, pos) {
+ if (evsel__strcmp(pos, evsel_name))
+ continue;
if (evsel__cpu_iter_skip(pos, cpu))
continue;
if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
@@ -403,15 +428,34 @@ void evlist__disable(struct evlist *evlist)

affinity__cleanup(&affinity);
evlist__for_each_entry(evlist, pos) {
+ if (evsel__strcmp(pos, evsel_name))
+ continue;
if (!evsel__is_group_leader(pos) || !pos->core.fd)
continue;
pos->disabled = true;
}

- evlist->enabled = false;
+ /*
+ * If we disabled only single event, we need to check
+ * the enabled state of the evlist manually.
+ */
+ if (evsel_name)
+ evlist->enabled = evlist__is_enabled(evlist);
+ else
+ evlist->enabled = false;
+}
+
+void evlist__disable(struct evlist *evlist)
+{
+ __evlist__disable(evlist, NULL);
+}
+
+void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
+{
+ __evlist__disable(evlist, evsel_name);
}

-void evlist__enable(struct evlist *evlist)
+static void __evlist__enable(struct evlist *evlist, char *evsel_name)
{
struct evsel *pos;
struct affinity affinity;
@@ -424,6 +468,8 @@ void evlist__enable(struct evlist *evlist)
affinity__set(&affinity, cpu);

evlist__for_each_entry(evlist, pos) {
+ if (evsel__strcmp(pos, evsel_name))
+ continue;
if (evsel__cpu_iter_skip(pos, cpu))
continue;
if (!evsel__is_group_leader(pos) || !pos->core.fd)
@@ -433,14 +479,31 @@ void evlist__enable(struct evlist *evlist)
}
affinity__cleanup(&affinity);
evlist__for_each_entry(evlist, pos) {
+ if (evsel__strcmp(pos, evsel_name))
+ continue;
if (!evsel__is_group_leader(pos) || !pos->core.fd)
continue;
pos->disabled = false;
}

+ /*
+ * Even single event sets the 'enabled' for evlist,
+ * so the toggle can work properly and toggle to
+ * 'disabled' state.
+ */
evlist->enabled = true;
}

+void evlist__enable(struct evlist *evlist)
+{
+ __evlist__enable(evlist, NULL);
+}
+
+void evlist__enable_evsel(struct evlist *evlist, char *evsel_name)
+{
+ __evlist__enable(evlist, evsel_name);
+}
+
void evlist__toggle_enable(struct evlist *evlist)
{
(evlist->enabled ? evlist__disable : evlist__enable)(evlist);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 9b0c795736bb..1aae75895dea 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -186,6 +186,8 @@ size_t evlist__mmap_size(unsigned long pages);
void evlist__disable(struct evlist *evlist);
void evlist__enable(struct evlist *evlist);
void evlist__toggle_enable(struct evlist *evlist);
+void evlist__disable_evsel(struct evlist *evlist, char *evsel_name);
+void evlist__enable_evsel(struct evlist *evlist, char *evsel_name);

int evlist__enable_event_idx(struct evlist *evlist, struct evsel *evsel, int idx);

--
2.26.2