From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 12 Oct 2017 16:54:27 +0000 (-0600)
Subject: flow: fix bad overflowing math
X-Git-Tag: fio-3.2~27
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=c13a60ce72aaf5b07b93977ab86e7522d167ec28

flow: fix bad overflowing math

No point in multiplying with a 1/-1 integer, just assign a local
variable appropriately.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/flow.c b/flow.c
index 42b6dd75..384187ef 100644
--- a/flow.c
+++ b/flow.c
@@ -16,13 +16,17 @@ static struct fio_mutex *flow_lock;
 int flow_threshold_exceeded(struct thread_data *td)
 {
 	struct fio_flow *flow = td->flow;
-	int sign;
+	long long flow_counter;
 
 	if (!flow)
 		return 0;
 
-	sign = td->o.flow > 0 ? 1 : -1;
-	if (sign * flow->flow_counter > td->o.flow_watermark) {
+	if (td->o.flow > 0)
+		flow_counter = flow->flow_counter;
+	else
+		flow_counter = -flow->flow_counter;
+
+	if (flow_counter > td->o.flow_watermark) {
 		if (td->o.flow_sleep) {
 			io_u_quiesce(td);
 			usleep(td->o.flow_sleep);