[PATCH 3/3] io_uring: inform block layer of how many requests we are submitting

Jens Axboe
2021-10-06T23:13:40Z

The block layer can use this knowledge to make smarter decisions on
how to handle the request, if it knows that N more may be coming. Switch
to using blk_start_plug_nr_ios() to pass in that information.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 73135c5c6168..90af264fdac6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -316,6 +316,7 @@ struct io_submit_state {

bool plug_started;
bool need_plug;
+ unsigned short submit_nr;
struct blk_plug plug;
};

@@ -7027,7 +7028,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
if (state->need_plug && io_op_defs[opcode].plug) {
state->plug_started = true;
state->need_plug = false;
- blk_start_plug(&state->plug);
+ blk_start_plug_nr_ios(&state->plug, state->submit_nr);
}

req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd),
@@ -7148,6 +7149,7 @@ static void io_submit_state_start(struct io_submit_state *state,
{
state->plug_started = false;
state->need_plug = max_ios > 2;
+ state->submit_nr = max_ios;
/* set only head, no need to init link_last in advance */
state->link.head = NULL;
}
--
2.33.0