Raise default jemalloc muzzy threshold.

Signed-off-by: Jason Volk <jason@zemos.net>

src/main/args.rs

@@ -155,7 +155,7 @@ pub struct Args {
 	/// memory to the operating system using MADV_FREE without MADV_DONTNEED.
 	/// Setting to false increases performance by reducing pagefaults, but
 	/// resident memory usage appears high until there is memory pressure. The
-	/// default is true unless the system has four or more cores.
+	/// default is true unless the system has eight or more cores.
 	#[arg(
 		long,
 		hide(true),

src/main/runtime.rs

@@ -25,7 +25,7 @@ const WORKER_KEEPALIVE: u64 = 36;
 const MAX_BLOCKING_THREADS: usize = 1024;
 const SHUTDOWN_TIMEOUT: Duration = Duration::from_millis(10000);
 #[cfg(all(not(target_env = "msvc"), feature = "jemalloc"))]
-const DISABLE_MUZZY_THRESHOLD: usize = 4;
+const DISABLE_MUZZY_THRESHOLD: usize = 8;
 
 static WORKER_AFFINITY: OnceLock<bool> = OnceLock::new();
 static GC_ON_PARK: OnceLock<Option<bool>> = OnceLock::new();