just not instrumented, validate that again, should be equivalent with f9528ec980

pageserver/src/page_service.rs

@@ -1076,6 +1076,13 @@ impl PageServerHandler {
 
             // what we want to do
             let flush_fut = pgb_writer.flush();
+            // metric for how long flushing takes
+            let flush_fut = match flushing_timer {
+                Some(flushing_timer) => {
+                    futures::future::Either::Left(flushing_timer.measure(flush_fut))
+                }
+                None => futures::future::Either::Right(flush_fut),
+            };
             // do it while respecting cancellation
             let _: () = async move {
                 tokio::select! {