test(tunnel): add netns bench warmup (#2623)

easytier/src/tunnel/common.rs

@@ -495,14 +495,16 @@ pub(crate) mod tests {
             let (mut r, _s) = ret.split();
             let now = Instant::now();
             let mut count = 0;
+            let warmup = std::time::Duration::from_secs(1);
             while let Some(Ok(p)) = r.next().await {
+                let elapsed = now.elapsed();
+                if elapsed < warmup {
+                    continue;
+                }
                 count += p.payload_len();
-                let elapsed_sec = now.elapsed().as_secs();
-                if elapsed_sec > 0 {
-                    bps_clone.store(
-                        count as u64 / now.elapsed().as_secs(),
-                        std::sync::atomic::Ordering::Relaxed,
-                    );
+                let elapsed = (elapsed - warmup).as_secs();
+                if elapsed >= 1 {
+                    bps_clone.store(count as u64 / elapsed, std::sync::atomic::Ordering::Relaxed);
                 }
             }
         });