On 9/4/19 2:10 PM, Jens Axboe wrote:
> On 9/3/19 5:49 AM, Jeff Moyer wrote:
>> Jens Axboe <axboe@xxxxxxxxx> writes:
>>
>>> On 8/29/19 10:38 AM, Jeff Moyer wrote:
>>>> Hi,
>>>>
>>>> sqthread_poll requires registered files in order to work. That's not
>>>> implemented in fio, and I don't see how one would go about it (but I'm
>>>> not all that familiar with fio's architecture). We basically need all
>>>> files to be opened before we can register them. It looks to me as
>>>> though the files are opened on demand, after the io engine is
>>>> initialized.
>>>>
>>>> Any suggestions?
>>>
>>> Leftover from previously, when that requirement wasn't there... Using
>>> it from fio would require a little bit of footwork, but it's not
>>> impossible.
>>
>> OK, if you can point me in the right direction, I'll take a stab at it.
>
> I think if we impose the restriction that the total number of files used
> must fit in a registered file set, it isn't too hard. Just have the
> engine open the files when it starts, and provide a new ->open_file()
> (and ->close_file()) in the engine ops.
>
> I'll take a stab at it.
Here's a quick 10 min hack to get this going, if you want to run with
this, that'd be great. What is still needed:
1) Test it... I just ran a basic test to verify it does what I think it
should, that's all.
2) Keep the standalone option, but make sqthread_poll imply this option
as well.
3) Probably add a check whether o->nr_files fits in a set. Or maybe it's
fine not to, the system call will complain anyway.
4) Ensure it works with things like loops= that restart things.
5) Probably various things I didn't think of yet.
diff --git a/engines/io_uring.c b/engines/io_uring.c
index 9bcfec1726b0..5d051c62d0ea 100644
--- a/engines/io_uring.c
+++ b/engines/io_uring.c
@@ -50,6 +50,8 @@ struct ioring_data {
struct io_u **io_u_index;
+ int *fds;
+
struct io_sq_ring sq_ring;
struct io_uring_sqe *sqes;
struct iovec *iovecs;
@@ -69,6 +71,7 @@ struct ioring_options {
void *pad;
unsigned int hipri;
unsigned int fixedbufs;
+ unsigned int registerfiles;
unsigned int sqpoll_thread;
unsigned int sqpoll_set;
unsigned int sqpoll_cpu;
@@ -102,6 +105,15 @@ static struct fio_option options[] = {
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_LIBAIO,
},
+ {
+ .name = "registerfiles",
+ .lname = "Register file set",
+ .type = FIO_OPT_STR_SET,
+ .off1 = offsetof(struct ioring_options, registerfiles),
+ .help = "Pre-open/register files",
+ .category = FIO_OPT_C_ENGINE,
+ .group = FIO_OPT_G_LIBAIO,
+ },
{
.name = "sqthread_poll",
.lname = "Kernel SQ thread polling",
@@ -140,8 +152,13 @@ static int fio_ioring_prep(struct thread_data *td, struct io_u *io_u)
struct io_uring_sqe *sqe;
sqe = &ld->sqes[io_u->index];
- sqe->fd = f->fd;
- sqe->flags = 0;
+ if (o->registerfiles) {
+ sqe->fd = f->engine_pos;
+ sqe->flags = IOSQE_FIXED_FILE;
+ } else {
+ sqe->fd = f->fd;
+ sqe->flags = 0;
+ }
sqe->ioprio = 0;
sqe->buf_index = 0;
@@ -388,6 +405,7 @@ static void fio_ioring_cleanup(struct thread_data *td)
free(ld->io_u_index);
free(ld->iovecs);
+ free(ld->fds);
free(ld);
}
}
@@ -476,9 +494,44 @@ static int fio_ioring_queue_init(struct thread_data *td)
return fio_ioring_mmap(ld, &p);
}
+static int fio_ioring_register_files(struct thread_data *td)
+{
+ struct ioring_data *ld = td->io_ops_data;
+ struct fio_file *f;
+ unsigned int i;
+ int ret;
+
+ ld->fds = calloc(td->o.nr_files, sizeof(int));
+
+ for_each_file(td, f, i) {
+ ret = generic_open_file(td, f);
+ if (ret)
+ goto err;
+ ld->fds[i] = f->fd;
+ f->engine_pos = i;
+ }
+
+ ret = syscall(__NR_sys_io_uring_register, ld->ring_fd,
+ IORING_REGISTER_FILES, ld->fds, td->o.nr_files);
+ if (ret) {
+err:
+ free(ld->fds);
+ ld->fds = NULL;
+ }
+
+ /*
+ * Pretend the file is closed again
+ */
+ for_each_file(td, f, i)
+ f->fd = -1;
+
+ return ret;
+}
+
static int fio_ioring_post_init(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
+ struct ioring_options *o = td->eo;
struct io_u *io_u;
int err, i;
@@ -496,6 +549,14 @@ static int fio_ioring_post_init(struct thread_data *td)
return 1;
}
+ if (o->registerfiles) {
+ err = fio_ioring_register_files(td);
+ if (err) {
+ td_verror(td, errno, "ioring_register_files");
+ return 1;
+ }
+ }
+
return 0;
}
@@ -530,6 +591,29 @@ static int fio_ioring_io_u_init(struct thread_data *td, struct io_u *io_u)
return 0;
}
+static int fio_ioring_open_file(struct thread_data *td, struct fio_file *f)
+{
+ struct ioring_data *ld = td->io_ops_data;
+ struct ioring_options *o = td->eo;
+
+ if (!o->registerfiles)
+ return generic_open_file(td, f);
+
+ f->fd = ld->fds[f->engine_pos];
+ return 0;
+}
+
+static int fio_ioring_close_file(struct thread_data *td, struct fio_file *f)
+{
+ struct ioring_options *o = td->eo;
+
+ if (!o->registerfiles)
+ return generic_close_file(td, f);
+
+ f->fd = -1;
+ return 0;
+}
+
static struct ioengine_ops ioengine = {
.name = "io_uring",
.version = FIO_IOOPS_VERSION,
@@ -543,8 +627,8 @@ static struct ioengine_ops ioengine = {
.getevents = fio_ioring_getevents,
.event = fio_ioring_event,
.cleanup = fio_ioring_cleanup,
- .open_file = generic_open_file,
- .close_file = generic_close_file,
+ .open_file = fio_ioring_open_file,
+ .close_file = fio_ioring_close_file,
.get_file_size = generic_get_file_size,
.options = options,
.option_struct_size = sizeof(struct ioring_options),
--
Jens Axboe
