[PATCH 5.15 15/73] io_uring: kill poll linking optimisation

From: Greg Kroah-Hartman
Date: Fri Sep 02 2022 - 08:42:53 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

[ upstream commmit ab1dab960b8352cee082db0f8a54dc92a948bfd7 ]

With IORING_FEAT_FAST_POLL in place, io_put_req_find_next() for poll
requests doesn't make much sense, and in any case re-adding it
shouldn't be a problem considering batching in tctx_task_work(). We can
remove it.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/15699682bf81610ec901d4e79d6da64baa9f70be.1639605189.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
[pavel: backport]
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5460,7 +5460,6 @@ static inline bool io_poll_complete(stru
static void io_poll_task_func(struct io_kiocb *req, bool *locked)
{
struct io_ring_ctx *ctx = req->ctx;
- struct io_kiocb *nxt;

if (io_poll_rewait(req, &req->poll)) {
spin_unlock(&ctx->completion_lock);
@@ -5484,11 +5483,8 @@ static void io_poll_task_func(struct io_
spin_unlock(&ctx->completion_lock);
io_cqring_ev_posted(ctx);

- if (done) {
- nxt = io_put_req_find_next(req);
- if (nxt)
- io_req_task_submit(nxt, locked);
- }
+ if (done)
+ io_put_req(req);
}
}