diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-10-15 17:09:13 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-19 05:49:55 -0600 |
| commit | d1d681b0846af8585904be562610bdfc70bf21aa (patch) | |
| tree | f3400d315fe383f3feccf36af9944072289374b7 | |
| parent | 9882131cd9de525d484de117644e5008c6557ac7 (diff) | |
io_uring: optimise io_import_iovec fixed path
Delay loading req->rw.{addr,len} in io_import_iovec until it's really
needed, so removing extra loads for the fixed path, which doesn't use
them.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3cc48dd0c4f1a37c4ce9aab5784281a2d83ad8be.1634314022.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 348e587524cf..00267e799ac2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3159,9 +3159,9 @@ static int __io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, struct io_rw_state *s, unsigned int issue_flags) { struct iov_iter *iter = &s->iter; - void __user *buf = u64_to_user_ptr(req->rw.addr); - size_t sqe_len = req->rw.len; u8 opcode = req->opcode; + void __user *buf; + size_t sqe_len; ssize_t ret; if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { @@ -3170,9 +3170,12 @@ static int __io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, } /* buffer index only valid with fixed read/write, or buffer select */ - if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT)) + if (unlikely(req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))) return -EINVAL; + buf = u64_to_user_ptr(req->rw.addr); + sqe_len = req->rw.len; + if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) { if (req->flags & REQ_F_BUFFER_SELECT) { buf = io_rw_buffer_select(req, &sqe_len, issue_flags); |