Add max_latency option

If set, fio will exit if it sees a total IO latency that exceeds
this value.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fio.1 b/fio.1
index bf65551..08d6c0f 100644
--- a/fio.1
+++ b/fio.1
@@ -639,6 +639,10 @@
 Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of
 milliseconds.  Default: 1000ms.
 .TP
+.BI max_latency \fR=\fPint
+If set, fio will exit the job if it exceeds this maximum latency. It will exit
+with an ETIME error.
+.TP
 .BI cpumask \fR=\fPint
 Set CPU affinity for this job. \fIint\fR is a bitmask of allowed CPUs the job
 may run on.  See \fBsched_setaffinity\fR\|(2).