t/io_uring: use non-vectored reads if available

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

diff --git a/t/io_uring.c b/t/io_uring.c
index 7fa84f99075bb8fb2f7c9ad0120edba911889a72..175095cfbc975000956753989f444092449e3189 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -94,6 +94,8 @@ static int sq_thread_poll = 0;        /* use kernel submission/poller thread */
 static int sq_thread_cpu = -1; /* pin above thread to this CPU */
 static int do_nop = 0;         /* no-op SQ ring commands */
 
+static int read_op = IORING_OP_READV;
+
 static int io_uring_register_buffers(struct submitter *s)
 {
        if (do_nop)
@@ -125,6 +127,29 @@ static int io_uring_setup(unsigned entries, struct io_uring_params *p)
        return syscall(__NR_io_uring_setup, entries, p);
 }
 
+static void io_uring_probe(int fd)
+{
+       struct io_uring_probe *p;
+       int ret;
+
+       p = malloc(sizeof(*p) + 256 * sizeof(struct io_uring_probe_op));
+       if (!p)
+               return;
+
+       memset(p, 0, sizeof(*p) + 256 * sizeof(struct io_uring_probe_op));
+       ret = syscall(__NR_io_uring_register, fd, IORING_REGISTER_PROBE, p, 256);
+       if (ret < 0)
+               goto out;
+
+       if (IORING_OP_READ > p->ops_len)
+               goto out;
+
+       if ((p->ops[IORING_OP_READ].flags & IO_URING_OP_SUPPORTED))
+               read_op = IORING_OP_READ;
+out:
+       free(p);
+}
+
 static int io_uring_enter(struct submitter *s, unsigned int to_submit,
                          unsigned int min_complete, unsigned int flags)
 {
@@ -184,11 +209,16 @@ static void init_io(struct submitter *s, unsigned index)
                sqe->addr = (unsigned long) s->iovecs[index].iov_base;
                sqe->len = bs;
                sqe->buf_index = index;
-       } else {
+       } else if (read_op == IORING_OP_READV) {
                sqe->opcode = IORING_OP_READV;
                sqe->addr = (unsigned long) &s->iovecs[index];
                sqe->len = 1;
                sqe->buf_index = 0;
+       } else {
+               sqe->opcode = IORING_OP_READ;
+               sqe->addr = (unsigned long) s->iovecs[index].iov_base;
+               sqe->len = bs;
+               sqe->buf_index = 0;
        }
        sqe->ioprio = 0;
        sqe->off = offset;
@@ -414,6 +444,8 @@ static int setup_ring(struct submitter *s)
        }
        s->ring_fd = fd;
 
+       io_uring_probe(fd);
+
        if (fixedbufs) {
                ret = io_uring_register_buffers(s);
                if (ret < 0) {