Add support for modifying the randomness of a workload
Fio supports random or sequential IO, or random IO with a number of
sequential IOs in between. The percentage_random options allows
more fine grained control over this. It defaults to 100, which would
make any random workload still purely random. If set below 100,
there will be some percentage of sequential IOs. This happens randomly,
but at the specified percentages.
The percentage_sequential option is just the complement of that, it
is guaranteed that:
percentage_sequential + percentage_random == 100%
The later setting has priority, each will adjust the other.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/options.c b/options.c
index 1219803..97c5b6f 100644
--- a/options.c
+++ b/options.c
@@ -376,6 +376,25 @@
return 0;
}
+static int str_perc_rand_cb(void *data, unsigned long long *val)
+{
+ struct thread_data *td = data;
+
+ td->o.perc_rand = *val;
+ td->o.perc_seq = 100 - *val;
+ return 0;
+}
+
+static int str_perc_seq_cb(void *data, unsigned long long *val)
+{
+ struct thread_data *td = data;
+
+ td->o.perc_seq = *val;
+ td->o.perc_rand = 100 - *val;
+ return 0;
+}
+
+
static int str_exitall_cb(void)
{
exitall_on_terminate = 1;
@@ -1643,6 +1662,32 @@
.group = FIO_OPT_G_RANDOM,
},
{
+ .name = "percentage_random",
+ .lname = "Percentage Random",
+ .type = FIO_OPT_INT,
+ .cb = str_perc_rand_cb,
+ .maxval = 100,
+ .help = "Percentage of seq/random mix that should be random",
+ .def = "100",
+ .interval = 5,
+ .inverse = "percentage_sequential",
+ .category = FIO_OPT_C_IO,
+ .group = FIO_OPT_G_RANDOM,
+ },
+ {
+ .name = "percentage_sequential",
+ .lname = "Percentage Sequential",
+ .type = FIO_OPT_INT,
+ .cb = str_perc_seq_cb,
+ .maxval = 100,
+ .help = "Percentage of seq/random mix that should be sequential",
+ .def = "0",
+ .interval = 5,
+ .inverse = "percentage_random",
+ .category = FIO_OPT_C_IO,
+ .group = FIO_OPT_G_RANDOM,
+ },
+ {
.name = "nrfiles",
.lname = "Number of files",
.alias = "nr_files",