Jens Axboe <axboe@xxxxxxxxx> writes:
> We currently merge async work items if we see a strict sequential hit.
> This helps avoid unnecessary workqueue switches when we don't need
> them. We can extend this merging to cover cases where it's not a strict
> sequential hit, but the IO still fits within the same page. If an
> application is doing multiple requests within the same page, we don't
> want separate workers waiting on the same page to complete IO. It's much
> faster to let the first worker bring in the page, then operate on that
> page from the same worker to complete the next request(s).
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Minor nit below.
> @@ -1994,7 +2014,7 @@ static void io_sq_wq_submit_work(struct work_struct *work)
> */
> static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req)
> {
> - bool ret = false;
> + bool ret;
>
> if (!list)
> return false;
This hunk looks unrelated. Also, I think you could actually change that
to be initialized to true, and get rid of the assignment later:
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 03fcd974fd1d..a94c8584c480 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1994,7 +1994,7 @@ static void io_sq_wq_submit_work(struct work_struct *work)
*/
static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req)
{
- bool ret = false;
+ bool ret = true;
if (!list)
return false;
@@ -2003,7 +2003,6 @@ static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req)
if (!atomic_read(&list->cnt))
return false;
- ret = true;
spin_lock(&list->lock);
list_add_tail(&req->list, &list->list);
/*
Cheers,
Jeff
