Add sample zipf distribution randomizer

[fio.git] / io_u.c

diff --git a/io_u.c b/io_u.c
index a2c583df26bb43943d7bda1ebf05e6999d9432b6..8f2ce302080c4ba8c1b54d5e8f41a7e408d5c902 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -157,8 +157,8 @@ static int get_next_free_block(struct thread_data *td, struct fio_file *f,
        return 1;
 }
 
-static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
-                               enum fio_ddir ddir, unsigned long long *b)
+static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
+                                 enum fio_ddir ddir, unsigned long long *b)
 {
        unsigned long long rmax, r, lastb;
        int loops = 5;
@@ -234,6 +234,25 @@ ret:
        return 0;
 }
 
+static int __get_next_rand_offset_zipf(struct thread_data *td, struct fio_file *f,
+                                 enum fio_ddir ddir, unsigned long long *b)
+{
+       *b = zipf_next(&td->zipf);
+       return 0;
+}
+
+static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
+                               enum fio_ddir ddir, unsigned long long *b)
+{
+       if (td->o.random_distribution == FIO_RAND_DIST_RANDOM)
+               return __get_next_rand_offset(td, f, ddir, b);
+       else if (td->o.random_distribution == FIO_RAND_DIST_ZIPF)
+               return __get_next_rand_offset_zipf(td, f, ddir, b);
+
+       log_err("fio: unknown random distribution: %d\n", td->o.random_distribution);
+       return 1;
+}
+
 static int get_next_rand_block(struct thread_data *td, struct fio_file *f,
                               enum fio_ddir ddir, unsigned long long *b)
 {
@@ -1096,7 +1115,7 @@ again:
 
                io_u->error = 0;
                flist_del(&io_u->list);
-               flist_add(&io_u->list, &td->io_u_busylist);
+               flist_add_tail(&io_u->list, &td->io_u_busylist);
                td->cur_depth++;
                io_u->flags |= IO_U_F_IN_CUR_DEPTH;
        } else if (td->o.verify_async) {
@@ -1325,6 +1344,13 @@ 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) {