io_uring: simplify waking sqo_sq_wait

Going through submission in __io_sq_thread() and still having a full SQ
is rather unexpected, so remove a check for SQ fullness and just wake up
whoever wait on sqo_sq_wait. Also skip if it doesn't do submission in
the first place, likely may to happen for SQPOLL sharing and/or IOPOLL.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e2e91751e87b1a39f8d63ef884aaff578123f61e.1621201931.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d18be5a..3a78899 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6801,10 +6801,10 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
                    !(ctx->flags & IORING_SETUP_R_DISABLED))
                        ret = io_submit_sqes(ctx, to_submit);
                mutex_unlock(&ctx->uring_lock);
-       }
 
-       if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait))
-               wake_up(&ctx->sqo_sq_wait);
+               if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait))
+                       wake_up(&ctx->sqo_sq_wait);
+       }
 
        return ret;
 }