perfetto: Throttle rss_stat event
If the ftrace config sets 'throttle_rss_stat' to true and the device
supports throttling trace events with synthetic events, use the
'synthetic/rss_stat_throttled' event instead of 'rss_stat'
Bug: 145972256
Test: out/android/trace_to_text <trace-w/-throttle_rss_stat>
| grep rss_stat_throttled
Change-Id: I304999fa53a02f4fdcd9011c2d9fd133c6551319
diff --git a/src/traced/probes/ftrace/ftrace_config_muxer.cc b/src/traced/probes/ftrace/ftrace_config_muxer.cc
index a19564f..9e8ba42 100644
--- a/src/traced/probes/ftrace/ftrace_config_muxer.cc
+++ b/src/traced/probes/ftrace/ftrace_config_muxer.cc
@@ -93,6 +93,12 @@
*out = std::move(v);
}
+bool SupportsRssStatThrottled(const FtraceProcfs& ftrace_procfs) {
+ const auto trigger_info = ftrace_procfs.ReadEventTrigger("kmem", "rss_stat");
+
+ return trigger_info.find("rss_stat_throttled") != std::string::npos;
+}
+
// This is just to reduce binary size and stack frame size of the insertions.
// It effectively undoes STL's set::insert inlining.
void PERFETTO_NO_INLINE InsertEvent(const char* group,
@@ -407,7 +413,12 @@
}
if (category == "memory") {
- InsertEvent("kmem", "rss_stat", &events);
+ // Use rss_stat_throttled if supported
+ if (SupportsRssStatThrottled(*ftrace_)) {
+ InsertEvent("synthetic", "rss_stat_throttled", &events);
+ } else {
+ InsertEvent("kmem", "rss_stat", &events);
+ }
InsertEvent("kmem", "ion_heap_grow", &events);
InsertEvent("kmem", "ion_heap_shrink", &events);
// ion_stat supersedes ion_heap_grow / shrink for kernel 4.19+
@@ -424,6 +435,20 @@
}
}
}
+
+ // If throttle_rss_stat: true, use the rss_stat_throttled event if supported
+ if (request.throttle_rss_stat() && SupportsRssStatThrottled(*ftrace_)) {
+ auto it = std::find_if(
+ events.begin(), events.end(), [](const GroupAndName& event) {
+ return event.group() == "kmem" && event.name() == "rss_stat";
+ });
+
+ if (it != events.end()) {
+ events.erase(it);
+ InsertEvent("synthetic", "rss_stat_throttled", &events);
+ }
+ }
+
return events;
}
diff --git a/src/traced/probes/ftrace/ftrace_procfs.cc b/src/traced/probes/ftrace/ftrace_procfs.cc
index c6d21d5..e393648 100644
--- a/src/traced/probes/ftrace/ftrace_procfs.cc
+++ b/src/traced/probes/ftrace/ftrace_procfs.cc
@@ -130,6 +130,12 @@
return ReadFileIntoString(path);
}
+std::string FtraceProcfs::ReadEventTrigger(const std::string& group,
+ const std::string& name) const {
+ std::string path = root_ + "events/" + group + "/" + name + "/trigger";
+ return ReadFileIntoString(path);
+}
+
std::string FtraceProcfs::ReadPrintkFormats() const {
std::string path = root_ + "printk_formats";
return ReadFileIntoString(path);
diff --git a/src/traced/probes/ftrace/ftrace_procfs.h b/src/traced/probes/ftrace/ftrace_procfs.h
index 81d3063..6e0791b 100644
--- a/src/traced/probes/ftrace/ftrace_procfs.h
+++ b/src/traced/probes/ftrace/ftrace_procfs.h
@@ -58,6 +58,10 @@
virtual std::string ReadPageHeaderFormat() const;
+ // Read the triggers for event with the given |group| and |name|.
+ std::string ReadEventTrigger(const std::string& group,
+ const std::string& name) const;
+
// Read the printk formats file.
std::string ReadPrintkFormats() const;
