From: Pavel Begunkov Date: Thu, 14 Oct 2021 15:10:14 +0000 (+0100) Subject: io_uring: optimise rw comletion handlers X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=258f3a7f84d11ce1d6cb1f60fe524bb37f7c1019;p=linux.git io_uring: optimise rw comletion handlers Don't override req->result in io_complete_rw_iopoll() when it's already of the same value, we have an if just above it, so move the assignment there. Also, add one simle unlikely() in __io_complete_rw_common(). Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/8dfeb4f84026a20172bcf82c05010abe955874ae.1634144845.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index 86ef803db27a0..18a91d268fb6b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2640,7 +2640,7 @@ static bool __io_complete_rw_common(struct io_kiocb *req, long res) { if (req->rw.kiocb.ki_flags & IOCB_WRITE) kiocb_end_write(req); - if (res != req->result) { + if (unlikely(res != req->result)) { if ((res == -EAGAIN || res == -EOPNOTSUPP) && io_rw_should_reissue(req)) { req->flags |= REQ_F_REISSUE; @@ -2695,9 +2695,9 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) req->flags |= REQ_F_REISSUE; return; } + req->result = res; } - req->result = res; /* order with io_iopoll_complete() checking ->iopoll_completed */ smp_store_release(&req->iopoll_completed, 1); }