Clarify in comment Perfetto binary size flags.
It's not obvious from code how the simple false value reduces the binary
size. Adds a comment to explain how it works and a warning about
changing the flag value.
Bug: 272207884
Test: It's a comment
Change-Id: I5ea733ef879e8e6ea1a2a6bfb3aa22b1fbedd6da
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
index dc5732f..6aa0fb4 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
@@ -101,6 +101,11 @@
void NetworkTraceHandler::InitPerfettoTracing() {
perfetto::TracingInitArgs args = {};
args.backends |= perfetto::kSystemBackend;
+ // The following line disables the Perfetto system consumer. Perfetto inlines
+ // the call to `Initialize` which allows the compiler to see that the branch
+ // with the SystemConsumerTracingBackend is not used. With LTO enabled, this
+ // strips the Perfetto consumer code and reduces the size of this binary by
+ // around 270KB total. Be careful when changing this value.
args.enable_system_consumer = false;
perfetto::Tracing::Initialize(args);
NetworkTraceHandler::RegisterDataSource();