io_uring: mark having different creds unlikely

Hint the compiler that it's not as likely to have creds different from
current attached to a request. The current code generation is far from
ideal, hopefully it can help to some compilers to remove duplicated jump
tables and so.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e7815251ac4bf5a4a23d298c752f029ae19f3837.1632516769.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 3ced6a7bdf2b5245bd8aa86153756b555eb19ee3..bda302bedeeff5e06137013201bc609466fb4941 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6638,7 +6638,7 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
        const struct cred *creds = NULL;
        int ret;
 
-       if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())
+       if (unlikely((req->flags & REQ_F_CREDS) && req->creds != current_cred()))
                creds = override_creds(req->creds);
 
        switch (req->opcode) {