Tie the process to a single CPU while profiling

To mitigate the effect of migration between big.LITTLE cores
Javier-varez · May 22, 2024 · d9fdcd2 · d9fdcd2
1 parent 6b2441e
commit d9fdcd2
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Showing 3 changed files with 41 additions and 2 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/rusty-boy-sdl/Cargo.toml b/rusty-boy-sdl/Cargo.toml
@@ -13,6 +13,7 @@ readme = "../README.md"
 
 [features]
 approximate = []
+profile = ["nix"]
 
 [dependencies]
 cartridge = { path = "../cartridge" }
@@ -25,3 +26,4 @@ sdl2 = "0.36"
 clap = { version = "4.5.4", features = ["derive"] }
 env_logger = "0.11.3"
 log = "0.4"
+nix = { version = "0.28", features = ["sched"], optional = true }
diff --git a/rusty-boy-sdl/src/main.rs b/rusty-boy-sdl/src/main.rs
@@ -128,7 +128,19 @@ fn save_file(rom_path: &Path, data: &[u8]) -> anyhow::Result<()> {
     Ok(())
 }
 
+#[cfg(feature = "profile")]
+fn configure_sched_affinity() -> anyhow::Result<()> {
+    log::info!("Setting CPU affinity");
+    let mut cpuset = nix::sched::CpuSet::new();
+    cpuset.set(0)?; // Just one cpu
+    nix::sched::sched_setaffinity(nix::unistd::Pid::this(), &cpuset)?;
+    Ok(())
+}
+
 fn main() -> anyhow::Result<()> {
+    #[cfg(feature = "profile")]
+    configure_sched_affinity()?;
+
     env_logger::init();
 
     let args = Args::parse();