t/io_uring: add -R option for random/sequential IO

If -R1 is used, which is the default, then a random IO pattern is used.
If -R0 is used, then the IO will be sequential.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/io_uring.c b/t/io_uring.c
index 5b8a00fa9a51b002f1c100ac4fa7fb3ef3de3fd1..b79822d72eba16dc85c89d944057cf04f9269200 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -60,6 +60,8 @@ static unsigned sq_ring_mask, cq_ring_mask;
 
 struct file {
        unsigned long max_blocks;
+       unsigned long max_size;
+       unsigned long cur_off;
        unsigned pending_ios;
        int real_fd;
        int fixed_fd;
@@ -123,7 +125,8 @@ static int do_nop = 0;              /* no-op SQ ring commands */
 static int nthreads = 1;
 static int stats = 0;          /* generate IO stats */
 static int aio = 0;            /* use libaio */
-static int runtime = 0;        /* runtime */
+static int runtime = 0;                /* runtime */
+static int random_io = 1;      /* random or sequential IO */
 
 static unsigned long tsc_rate;
 
@@ -451,8 +454,15 @@ static void init_io(struct submitter *s, unsigned index)
        }
        f->pending_ios++;
 
-       r = __rand64(&s->rand_state);
-       offset = (r % (f->max_blocks - 1)) * bs;
+       if (random_io) {
+               r = __rand64(&s->rand_state);
+               offset = (r % (f->max_blocks - 1)) * bs;
+       } else {
+               offset = f->cur_off;
+               f->cur_off += bs;
+               if (f->cur_off + bs > f->max_size)
+                       f->cur_off = 0;
+       }
 
        if (register_files) {
                sqe->flags = IOSQE_FIXED_FILE;
@@ -520,9 +530,11 @@ static int get_file_size(struct file *f)
                        return -1;
 
                f->max_blocks = bytes / bs;
+               f->max_size = bytes;
                return 0;
        } else if (S_ISREG(st.st_mode)) {
                f->max_blocks = st.st_size / bs;
+               f->max_size = st.st_size;
                return 0;
        }
 
@@ -1070,11 +1082,12 @@ static void usage(char *argv, int status)
                " -N <bool> : Perform just no-op requests, default %d\n"
                " -t <bool> : Track IO latencies, default %d\n"
                " -T <int>  : TSC rate in HZ\n"
-               " -a <bool> : Use legacy aio, default %d\n"
-               " -r <int>  : Runtime in seconds, default %s\n",
+               " -r <int>  : Runtime in seconds, default %s\n"
+               " -R <bool> : Use random IO, default %d\n"
+               " -a <bool> : Use legacy aio, default %d\n",
                argv, DEPTH, BATCH_SUBMIT, BATCH_COMPLETE, BS, polled,
                fixedbufs, dma_map, register_files, nthreads, !buffered, do_nop,
-               stats, aio, runtime == 0 ? "unlimited" : runtime_str);
+               stats, runtime == 0 ? "unlimited" : runtime_str, aio, random_io);
        exit(status);
 }
 
@@ -1134,7 +1147,7 @@ int main(int argc, char *argv[])
        if (!do_nop && argc < 2)
                usage(argv[0], 1);
 
-       while ((opt = getopt(argc, argv, "d:s:c:b:p:B:F:n:N:O:t:T:a:r:D:h?")) != -1) {
+       while ((opt = getopt(argc, argv, "d:s:c:b:p:B:F:n:N:O:t:T:a:r:D:R:h?")) != -1) {
                switch (opt) {
                case 'a':
                        aio = !!atoi(optarg);
@@ -1198,6 +1211,9 @@ int main(int argc, char *argv[])
                case 'D':
                        dma_map = !!atoi(optarg);
                        break;
+               case 'R':
+                       random_io = !!atoi(optarg);
+                       break;
                case 'h':
                case '?':
                default: