engines/io_uring: use non-vectored read/write if available

[fio.git] / engines / io_uring.c

diff --git a/engines/io_uring.c b/engines/io_uring.c
index 2b1b13570d91972e7f3a30d8e4782132afffbfcf..ec8cb18a354ee9f7ea6a29d31744a9a71836b24a 100644 (file)
--- a/engines/io_uring.c
+++ b/engines/io_uring.c
@@ -174,6 +174,7 @@ static struct fio_option options[] = {
                .lname  = "Non-vectored",
                .type   = FIO_OPT_INT,
                .off1   = offsetof(struct ioring_options, nonvectored),
+               .def    = "-1",
                .help   = "Use non-vectored read/write commands",
                .category = FIO_OPT_C_ENGINE,
                .group  = FIO_OPT_G_IOURING,
@@ -547,6 +548,40 @@ static int fio_ioring_mmap(struct ioring_data *ld, struct io_uring_params *p)
        return 0;
 }
 
+static void fio_ioring_probe(struct thread_data *td)
+{
+       struct ioring_data *ld = td->io_ops_data;
+       struct ioring_options *o = td->eo;
+       struct io_uring_probe *p;
+       int ret;
+
+       /* already set by user, don't touch */
+       if (o->nonvectored != -1)
+               return;
+
+       /* default to off, as that's always safe */
+       o->nonvectored = 0;
+
+       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, ld->ring_fd,
+                       IORING_REGISTER_PROBE, p, 256);
+       if (ret < 0)
+               goto out;
+
+       if (IORING_OP_WRITE > p->ops_len)
+               goto out;
+
+       if ((p->ops[IORING_OP_READ].flags & IO_URING_OP_SUPPORTED) &&
+           (p->ops[IORING_OP_WRITE].flags & IO_URING_OP_SUPPORTED))
+               o->nonvectored = 1;
+out:
+       free(p);
+}
+
 static int fio_ioring_queue_init(struct thread_data *td)
 {
        struct ioring_data *ld = td->io_ops_data;
@@ -573,6 +608,8 @@ static int fio_ioring_queue_init(struct thread_data *td)
 
        ld->ring_fd = ret;
 
+       fio_ioring_probe(td);
+
        if (o->fixedbufs) {
                ret = syscall(__NR_io_uring_register, ld->ring_fd,
                                IORING_REGISTER_BUFFERS, ld->iovecs, depth);