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 8eda99d00bd057a8199107e5508a5fa7d3ebd415..a7bd1fb07da4a9ad872e054958ee39514fadc0dc 100644 (file)
--- 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 bf65551811a91b931ba66ebddda7392dc41e2133..08d6c0f4ba3da66191ba855de21f60a4ed0b838c 100644 (file)
--- 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 03e4da1427d251fa5059900cfda102aba411f444..139b9383f9fbd3ebaf1598b77ecbce244926465a 100644 (file)
--- 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 e047677e1b507d0923dfe781f5c354f63248a62c..b049b61853fdfbd305ad01d857046be88dc68671 100644 (file)
--- 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 e0b7fec2e4970bcd383451c74a6da53dd803984b..380df36afd29f527d33d3949930ebe5f33d676a9 100644 (file)
--- 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,