Add Tracy allocation profiling feature flag

Cargo.toml

@@ -124,6 +124,8 @@ xdp-gnome-screencast = ["dbus", "pipewire"]
 profile-with-tracy = ["profiling/profile-with-tracy", "tracy-client/default"]
 # Enables the on-demand Tracy profiler instrumentation.
 profile-with-tracy-ondemand = ["profile-with-tracy", "tracy-client/ondemand", "tracy-client/manual-lifetime"]
+# Enables Tracy allocation profiling.
+profile-with-tracy-allocations = ["profile-with-tracy"]
 # Enables dinit integration (global environment).
 dinit = []
 

src/main.rs

@@ -33,6 +33,11 @@ use tracing_subscriber::EnvFilter;
 
 const DEFAULT_LOG_FILTER: &str = "niri=debug,smithay::backend::renderer::gles=error";
 
+#[cfg(feature = "profile-with-tracy-allocations")]
+#[global_allocator]
+static GLOBAL: tracy_client::ProfiledAllocator<std::alloc::System> =
+    tracy_client::ProfiledAllocator::new(std::alloc::System, 100);
+
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     // Set backtrace defaults if not set.
     if env::var_os("RUST_BACKTRACE").is_none() {

wiki/Developing-niri.md

@@ -72,3 +72,5 @@ pub fn some_function() {
     // Code of the function.
 }
 ```
+
+You can also enable Rust memory allocation profiling with `--features=profile-with-tracy-allocations`.