From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 9 Mar 2007 12:45:11 +0000 (+0100)
Subject: null engine: fix queue bug with repeated commit() calls before event retrieval
X-Git-Tag: fio-1.14~49
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=7401c088106ba35dcfba62ec753b6b20b72ad0e2;hp=65afa5f2146ee010b7129934f68e691faee54982

null engine: fix queue bug with repeated commit() calls before event retrieval

Don't return anything if min_events == 0. This exposed a bug in
the commit handler, it needs to add to ->events, not set it.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/engines/null.c b/engines/null.c
index 19886789..67ac4535 100644
--- a/engines/null.c
+++ b/engines/null.c
@@ -24,14 +24,17 @@ static struct io_u *fio_null_event(struct thread_data *td, int event)
 	return nd->io_us[event];
 }
 
-static int fio_null_getevents(struct thread_data *td, int fio_unused min,
+static int fio_null_getevents(struct thread_data *td, int min_events,
 			      int fio_unused max, struct timespec fio_unused *t)
 {
 	struct null_data *nd = td->io_ops->data;
-	int ret;
+	int ret = 0;
+	
+	if (min_events) {
+		ret = nd->events;
+		nd->events = 0;
+	}
 
-	ret = nd->events;
-	nd->events = 0;
 	return ret;
 }
 
@@ -39,7 +42,7 @@ static int fio_null_commit(struct thread_data *td)
 {
 	struct null_data *nd = td->io_ops->data;
 
-	nd->events = nd->queued;
+	nd->events += nd->queued;
 	nd->queued = 0;
 	return 0;
 }