t/io_uring: add support for registering the ring fd

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

diff --git a/t/io_uring.c b/t/io_uring.c
index ed405fa146f6494db8c21843846eeb14cb78937a..b160f5d4a1af3b14ed073725e771b7792e4c220b 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -76,6 +76,7 @@ struct file {
 struct submitter {
        pthread_t thread;
        int ring_fd;
+       int enter_ring_fd;
        int index;
        struct io_sq_ring sq_ring;
        struct io_uring_sqe *sqes;
@@ -127,6 +128,7 @@ static int stats = 0;               /* generate IO stats */
 static int aio = 0;            /* use libaio */
 static int runtime = 0;                /* runtime */
 static int random_io = 1;      /* random or sequential IO */
+static int register_ring = 1;  /* register ring */
 
 static unsigned long tsc_rate;
 
@@ -420,12 +422,14 @@ out:
 static int io_uring_enter(struct submitter *s, unsigned int to_submit,
                          unsigned int min_complete, unsigned int flags)
 {
+       if (register_ring)
+               flags |= IORING_ENTER_REGISTERED_RING;
 #ifdef FIO_ARCH_HAS_SYSCALL
-       return __do_syscall6(__NR_io_uring_enter, s->ring_fd, to_submit,
+       return __do_syscall6(__NR_io_uring_enter, s->enter_ring_fd, to_submit,
                                min_complete, flags, NULL, 0);
 #else
-       return syscall(__NR_io_uring_enter, s->ring_fd, to_submit, min_complete,
-                       flags, NULL, 0);
+       return syscall(__NR_io_uring_enter, s->enter_ring_fd, to_submit,
+                       min_complete, flags, NULL, 0);
 #endif
 }
 
@@ -793,6 +797,34 @@ static void *submitter_aio_fn(void *data)
 }
 #endif
 
+static void io_uring_unregister_ring(struct submitter *s)
+{
+       struct io_uring_rsrc_update up = {
+               .offset = s->enter_ring_fd,
+       };
+
+       syscall(__NR_io_uring_register, s->ring_fd, IORING_UNREGISTER_RING_FDS,
+               &up, 1);
+}
+
+static int io_uring_register_ring(struct submitter *s)
+{
+       struct io_uring_rsrc_update up = {
+               .data   = s->ring_fd,
+               .offset = -1U,
+       };
+       int ret;
+
+       ret = syscall(__NR_io_uring_register, s->ring_fd,
+                       IORING_REGISTER_RING_FDS, &up, 1);
+       if (ret == 1) {
+               s->enter_ring_fd = up.offset;
+               return 0;
+       }
+       register_ring = 0;
+       return -1;
+}
+
 static void *submitter_uring_fn(void *data)
 {
        struct submitter *s = data;
@@ -804,6 +836,9 @@ static void *submitter_uring_fn(void *data)
        submitter_init(s);
 #endif
 
+       if (register_ring)
+               io_uring_register_ring(s);
+
        prepped = 0;
        do {
                int to_wait, to_submit, this_reap, to_prep;
@@ -896,6 +931,9 @@ submit:
                }
        } while (!s->finish);
 
+       if (register_ring)
+               io_uring_unregister_ring(s);
+
        finish = 1;
        return NULL;
 }
@@ -998,7 +1036,7 @@ static int setup_ring(struct submitter *s)
                perror("io_uring_setup");
                return 1;
        }
-       s->ring_fd = fd;
+       s->ring_fd = s->enter_ring_fd = fd;
 
        io_uring_probe(fd);
 
@@ -1103,10 +1141,12 @@ static void usage(char *argv, int status)
                " -T <int>  : TSC rate in HZ\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",
+               " -a <bool> : Use legacy aio, default %d\n"
+               " -X <bool> : Use registered ring %d\n",
                argv, DEPTH, BATCH_SUBMIT, BATCH_COMPLETE, BS, polled,
                fixedbufs, dma_map, register_files, nthreads, !buffered, do_nop,
-               stats, runtime == 0 ? "unlimited" : runtime_str, random_io, aio);
+               stats, runtime == 0 ? "unlimited" : runtime_str, random_io, aio,
+               register_ring);
        exit(status);
 }
 
@@ -1167,7 +1207,7 @@ 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:R:h?")) != -1) {
+       while ((opt = getopt(argc, argv, "d:s:c:b:p:B:F:n:N:O:t:T:a:r:D:R:X:h?")) != -1) {
                switch (opt) {
                case 'a':
                        aio = !!atoi(optarg);
@@ -1234,6 +1274,9 @@ int main(int argc, char *argv[])
                case 'R':
                        random_io = !!atoi(optarg);
                        break;
+               case 'X':
+                       register_ring = !!atoi(optarg);
+                       break;
                case 'h':
                case '?':
                default: