Add option to select how to service multiple files
Right now we just round robin the open files, but sometimes you
just want to randomly go through the files. Add a 'file_service'
option for that, default to round robin still.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index 959e52f..8c46b3f 100644
--- a/fio.h
+++ b/fio.h
@@ -280,7 +280,10 @@
struct fio_file *files;
unsigned int nr_files;
unsigned int nr_uniq_files;
- unsigned int next_file;
+ union {
+ unsigned int next_file;
+ os_random_state_t next_file_state;
+ };
int error;
pid_t pid;
char *orig_buffer;
@@ -340,6 +343,7 @@
unsigned int rwmixread;
unsigned int rwmixwrite;
unsigned int nice;
+ unsigned int file_service_type;
char *read_iolog_file;
char *write_iolog_file;
@@ -437,6 +441,14 @@
};
/*
+ * roundrobin available files, or choose one at random.
+ */
+enum {
+ FIO_FSERVICE_RANDOM = 1,
+ FIO_FSERVICE_RR = 2,
+};
+
+/*
* 30 second per-io_u timeout, with 5 second intervals to avoid resetting
* the timer on each queue operation.
*/
diff --git a/init.c b/init.c
index c8f27ad..01e615f 100644
--- a/init.c
+++ b/init.c
@@ -33,6 +33,7 @@
#endif
static int str_exitall_cb(void);
static int str_cpumask_cb(void *, unsigned int *);
+static int str_file_service_cb(void *, const char *);
#define __stringify_1(x) #x
#define __stringify(x) __stringify_1(x)
@@ -153,6 +154,14 @@
.def = "1",
},
{
+ .name = "file_service_type",
+ .type = FIO_OPT_STR,
+ .cb = str_file_service_cb,
+ .help = "How to select which file to service next",
+ .def = "roundrobin",
+ .posval = { "random", "roundrobin" },
+ },
+ {
.name = "fsync",
.type = FIO_OPT_INT,
.off1 = td_var_offset(fsync_blocks),
@@ -841,7 +850,7 @@
*/
int init_random_state(struct thread_data *td)
{
- unsigned long seeds[4];
+ unsigned long seeds[5];
int fd, num_maps, blocks, i;
struct fio_file *f;
@@ -865,12 +874,13 @@
os_random_seed(seeds[0], &td->bsrange_state);
os_random_seed(seeds[1], &td->verify_state);
os_random_seed(seeds[2], &td->rwmix_state);
+ os_random_seed(seeds[3], &td->next_file_state);
if (td->sequential)
return 0;
if (td->rand_repeatable)
- seeds[3] = FIO_RANDSEED * td->thread_number;
+ seeds[4] = FIO_RANDSEED * td->thread_number;
if (!td->norandommap) {
for_each_file(td, f, i) {
@@ -882,7 +892,7 @@
}
}
- os_random_seed(seeds[3], &td->random_state);
+ os_random_seed(seeds[4], &td->random_state);
return 0;
}
@@ -1087,6 +1097,22 @@
return 0;
}
+static int str_file_service_cb(void *data, const char *str)
+{
+ struct thread_data *td = data;
+
+ if (!strncmp(str, "random", 6)) {
+ td->file_service_type = FIO_FSERVICE_RANDOM;
+ return 0;
+ } else if (!strncmp(str, "roundrobin", 10)) {
+ td->file_service_type = FIO_FSERVICE_RR;
+ return 0;
+ }
+
+ log_err("fio: file_service= random, roundrobin\n");
+ return 1;
+}
+
/*
* This is our [ini] type file parser.
*/
diff --git a/io_u.c b/io_u.c
index ab85193..6fb754e 100644
--- a/io_u.c
+++ b/io_u.c
@@ -325,7 +325,27 @@
td->io_u_lat[index]++;
}
-static struct fio_file *get_next_file(struct thread_data *td)
+/*
+ * Get next file to service by choosing one at random
+ */
+static struct fio_file *get_next_file_rand(struct thread_data *td)
+{
+ long r = os_random_long(&td->next_file_state);
+ unsigned int fileno;
+ struct fio_file *f;
+
+ do {
+ fileno = (unsigned int) ((double) (td->nr_files - 1) * r / (RAND_MAX + 1.0));
+ f = &td->files[fileno];
+ if (f->fd != -1)
+ return f;
+ } while (1);
+}
+
+/*
+ * Get next file to service by doing round robin between all available ones
+ */
+static struct fio_file *get_next_file_rr(struct thread_data *td)
{
unsigned int old_next_file = td->next_file;
struct fio_file *f;
@@ -393,7 +413,11 @@
if (io_u->file)
goto out;
- f = get_next_file(td);
+ if (td->file_service_type == FIO_FSERVICE_RR)
+ f = get_next_file_rr(td);
+ else
+ f = get_next_file_rand(td);
+
if (!f) {
put_io_u(td, io_u);
return NULL;