From efd0f0cd10c73d82bfc35be1532820c79f13fc4e Mon Sep 17 00:00:00 2001
From: oech3 <79379754+oech3@users.noreply.github.com>
Date: Mon, 6 Apr 2026 15:40:04 +0900
Subject: [PATCH] cat: avoid unnecessary allocation

---
 src/uu/cat/src/cat.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/uu/cat/src/cat.rs b/src/uu/cat/src/cat.rs
index a572e56d2..f9916ef40 100644
--- a/src/uu/cat/src/cat.rs
+++ b/src/uu/cat/src/cat.rs
@@ -489,6 +489,10 @@ fn write_fast<R: FdReadable>(handle: &mut InputHandle<R>) -> CatResult<()> {
     // If we're not on Linux or Android, or the splice() call failed,
     // fall back on slower writing.
     let mut stdout_lock = stdout.lock();
+    // stack allocation is overhead when splice succeed
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    let mut buf = vec![0; 1024 * 64];
+    #[cfg(not(any(target_os = "linux", target_os = "android")))]
     let mut buf = [0; 1024 * 64];
     loop {
         match handle.reader.read(&mut buf) {