From f3b8306b3436ed0537558ddb7340534f9e2c42ef Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Mon, 26 May 2025 10:31:00 -0400
Subject: bench/ioq: Don't track the latency of failed requests

This fixes a hang observed with low queue depths like -d32.
---
 bench/ioq.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

(limited to 'bench/ioq.c')

diff --git a/bench/ioq.c b/bench/ioq.c
index 61c9714..aca97dd 100644
--- a/bench/ioq.c
+++ b/bench/ioq.c
@@ -63,14 +63,8 @@ static void times_init(struct times *times) {
 	gettime(&times->start);
 }
 
-/** Start timing a single request. */
-static void start_request(struct times *times) {
-	gettime(&times->req_start);
-	times->timing = true;
-}
-
 /** Finish timing a request. */
-static void finish_request(struct times *times) {
+static void track_latency(struct times *times) {
 	struct timespec elapsed;
 	gettime(&elapsed);
 	timespec_sub(&elapsed, &times->req_start);
@@ -127,8 +121,8 @@ static bool push(struct ioq *ioq, enum ioq_nop_type type, struct times *lap) {
 
 	// Track latency for a small fraction of requests
 	if (!lap->timing && (lap->pushed + 1) % 128 == 0) {
-		start_request(lap);
 		ptr = lap;
+		gettime(&lap->req_start);
 	}
 
 	int ret = ioq_nop(ioq, type, ptr);
@@ -138,6 +132,9 @@ static bool push(struct ioq *ioq, enum ioq_nop_type type, struct times *lap) {
 	}
 
 	++lap->pushed;
+	if (ptr) {
+		lap->timing = true;
+	}
 	return true;
 }
 
@@ -149,7 +146,7 @@ static bool pop(struct ioq *ioq, struct times *lap, bool block) {
 	}
 
 	if (ent->ptr) {
-		finish_request(lap);
+		track_latency(lap);
 	}
 
 	ioq_free(ioq, ent);
-- 
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