microsoft
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WSL2-Linux-Kernel
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io_uring: do not recalculate ppos unnecessarily 

There is a slight optimisation to be had by calculating the correct pos
pointer inside io_kiocb_update_pos and then using that later.

It seems code size drops by a bit:
000000000000a1b0 0000000000000400 t io_read
000000000000a5b0 0000000000000319 t io_write

vs
000000000000a1b0 00000000000003f6 t io_read
000000000000a5b0 0000000000000310 t io_write

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Dylan Yudaken 2022-02-22 02:55:03 -08:00 коммит произвёл Jens Axboe
Родитель d34e1e5b39
Коммит b4aec40015
1 изменённых файлов: 12 добавлений и 6 удалений
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18
fs/io_uring.c
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@ -3086,18 +3086,22 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
}
}
static inline void io_kiocb_update_pos(struct io_kiocb *req)
static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
{
struct kiocb *kiocb = &req->rw.kiocb;
bool is_stream = req->file->f_mode & FMODE_STREAM;
if (kiocb->ki_pos == -1) {
if (!(req->file->f_mode & FMODE_STREAM)) {
if (!is_stream) {
req->flags |= REQ_F_CUR_POS;
kiocb->ki_pos = req->file->f_pos;
return &kiocb->ki_pos;
} else {
kiocb->ki_pos = 0;
return NULL;
}
}
return is_stream ? NULL : &kiocb->ki_pos;
}
static void kiocb_done(struct io_kiocb *req, ssize_t ret,
@ -3658,6 +3662,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
struct io_async_rw *rw;
ssize_t ret, ret2;
loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
@ -3688,9 +3693,9 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
kiocb->ki_flags &= ~IOCB_NOWAIT;
}
io_kiocb_update_pos(req);
ppos = io_kiocb_update_pos(req);
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
ret = rw_verify_area(READ, req->file, ppos, req->result);
if (unlikely(ret)) {
kfree(iovec);
return ret;
@ -3789,6 +3794,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
struct kiocb *kiocb = &req->rw.kiocb;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
ssize_t ret, ret2;
loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(WRITE, req, &iovec, s, issue_flags);
@ -3819,9 +3825,9 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
kiocb->ki_flags &= ~IOCB_NOWAIT;
}
io_kiocb_update_pos(req);
ppos = io_kiocb_update_pos(req);
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
ret = rw_verify_area(WRITE, req->file, ppos, req->result);
if (unlikely(ret))
goto out_free;