engines/rbd: add option to busy poll on event completion

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/engines/rbd.c b/engines/rbd.c
index b747e1b95bd0615a73d4503976e157ac8f407c8f..cf7be0acd1e3154e47bc36fcd9bea8a58a1e5433 100644 (file)
--- a/engines/rbd.c
+++ b/engines/rbd.c
@@ -26,6 +26,7 @@ struct rbd_options {
        char *rbd_name;
        char *pool_name;
        char *client_name;
+       int busy_poll;
 };
 
 static struct fio_option options[] = {
@@ -39,22 +40,32 @@ static struct fio_option options[] = {
                .group          = FIO_OPT_G_RBD,
        },
        {
-               .name     = "pool",
-               .lname    = "rbd engine pool",
-               .type     = FIO_OPT_STR_STORE,
-               .help     = "Name of the pool hosting the RBD for the RBD engine",
-               .off1     = offsetof(struct rbd_options, pool_name),
-               .category = FIO_OPT_C_ENGINE,
-               .group    = FIO_OPT_G_RBD,
+               .name           = "pool",
+               .lname          = "rbd engine pool",
+               .type           = FIO_OPT_STR_STORE,
+               .help           = "Name of the pool hosting the RBD for the RBD engine",
+               .off1           = offsetof(struct rbd_options, pool_name),
+               .category       = FIO_OPT_C_ENGINE,
+               .group          = FIO_OPT_G_RBD,
        },
        {
-               .name     = "clientname",
-               .lname    = "rbd engine clientname",
-               .type     = FIO_OPT_STR_STORE,
-               .help     = "Name of the ceph client to access the RBD for the RBD engine",
-               .off1     = offsetof(struct rbd_options, client_name),
-               .category = FIO_OPT_C_ENGINE,
-               .group    = FIO_OPT_G_RBD,
+               .name           = "clientname",
+               .lname          = "rbd engine clientname",
+               .type           = FIO_OPT_STR_STORE,
+               .help           = "Name of the ceph client to access the RBD for the RBD engine",
+               .off1           = offsetof(struct rbd_options, client_name),
+               .category       = FIO_OPT_C_ENGINE,
+               .group          = FIO_OPT_G_RBD,
+       },
+       {
+               .name           = "busy_poll",
+               .lname          = "Busy poll",
+               .type           = FIO_OPT_BOOL,
+               .help           = "Busy poll for completions instead of sleeping",
+               .off1           = offsetof(struct rbd_options, client_name),
+               .def            = "0",
+               .category       = FIO_OPT_C_ENGINE,
+               .group          = FIO_OPT_G_RBD,
        },
        {
                .name = NULL,
@@ -242,6 +253,7 @@ static int fio_rbd_getevents(struct thread_data *td, unsigned int min,
                             unsigned int max, const struct timespec *t)
 {
        unsigned int this_events, events = 0;
+       struct rbd_options *o = td->eo;
        int wait = 0;
 
        do {
@@ -252,7 +264,10 @@ static int fio_rbd_getevents(struct thread_data *td, unsigned int min,
                if (this_events)
                        continue;
 
-               wait = 1;
+               if (!o->busy_poll)
+                       wait = 1;
+               else
+                       nop;
        } while (1);
 
        return events;