From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 24 Oct 2012 14:37:45 +0000 (+0200)
Subject: Add max_latency option
X-Git-Tag: fio-2.0.11~41
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=155015351132ad00e2e21cb63f52fee91e56e92a

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/HOWTO b/HOWTO
index 8eda99d0..a7bd1fb0 100644
--- a/HOWTO
+++ b/HOWTO
@@ -780,6 +780,9 @@ rate_iops_min=int If fio doesn't meet this rate of IO, it will cause
 		the job to exit. The same format as rate is used for read vs
 		write seperation.
 
+max_latency=int	If set, fio will exit the job if it exceeds this maximum
+		latency. It will exit with an ETIME error.
+
 ratecycle=int	Average bandwidth for 'rate' and 'ratemin' over this number
 		of milliseconds.
 
diff --git a/fio.1 b/fio.1
index bf655518..08d6c0f4 100644
--- a/fio.1
+++ b/fio.1
@@ -639,6 +639,10 @@ is used for read vs write seperation.
 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).
diff --git a/fio.h b/fio.h
index 03e4da14..139b9383 100644
--- a/fio.h
+++ b/fio.h
@@ -198,6 +198,8 @@ struct thread_options {
 	enum fio_memtype mem_type;
 	unsigned int mem_align;
 
+	unsigned int max_latency;
+
 	unsigned int stonewall;
 	unsigned int new_group;
 	unsigned int numjobs;
diff --git a/io_u.c b/io_u.c
index e047677e..b049b618 100644
--- a/io_u.c
+++ b/io_u.c
@@ -1325,6 +1325,13 @@ static void account_io_completion(struct thread_data *td, struct io_u *io_u,
 
 		tusec = utime_since(&io_u->start_time, &icd->time);
 		add_lat_sample(td, idx, tusec, bytes);
+
+		if (td->o.max_latency && tusec > td->o.max_latency) {
+			if (!td->error)
+				log_err("fio: latency of %lu usec exceeds specified max (%u usec)\n", tusec, td->o.max_latency);
+			td_verror(td, ETIME, "max latency exceeded");
+			icd->error = ETIME;
+		}
 	}
 
 	if (!td->o.disable_clat) {
diff --git a/options.c b/options.c
index e0b7fec2..380df36a 100644
--- a/options.c
+++ b/options.c
@@ -2098,6 +2098,12 @@ static struct fio_option options[FIO_MAX_OPTS] = {
 		.def	= "1000",
 		.parent = "rate",
 	},
+	{
+		.name	= "max_latency",
+		.type	= FIO_OPT_INT,
+		.off1	= td_var_offset(max_latency),
+		.help	= "Maximum tolerated IO latency (usec)",
+	},
 	{
 		.name	= "invalidate",
 		.type	= FIO_OPT_BOOL,