On 4/16/21 7:25 AM, Pavel Begunkov wrote:
> On 16/04/2021 02:25, Jens Axboe wrote:
>> We have this in two spots right now, which is a bit fragile. In
>> preparation for moving REQ_F_POLLED cleanup into the same spot, move
>> the check into io_clean_op() itself so we only have it once.
>>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>> ---
>> fs/io_uring.c | 19 ++++++++-----------
>> 1 file changed, 8 insertions(+), 11 deletions(-)
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index 87ce3dbcd4ca..a668d6a3319c 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -1601,8 +1601,7 @@ static void io_req_complete_post(struct io_kiocb *req, long res,
>> static void io_req_complete_state(struct io_kiocb *req, long res,
>> unsigned int cflags)
>> {
>> - if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED))
>> - io_clean_op(req);
>> + io_clean_op(req);
>> req->result = res;
>> req->compl.cflags = cflags;
>> req->flags |= REQ_F_COMPLETE_INLINE;
>> @@ -1713,16 +1712,12 @@ static void io_dismantle_req(struct io_kiocb *req)
>>
>> if (!(flags & REQ_F_FIXED_FILE))
>> io_put_file(req->file);
>> - if (flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED |
>> - REQ_F_INFLIGHT)) {
>> - io_clean_op(req);
>> + io_clean_op(req);
>> + if (req->flags & REQ_F_INFLIGHT) {
>> + struct io_uring_task *tctx = req->task->io_uring;
>
> Not in particular happy about it.
> 1. adds extra if
> 2. adds extra function call
> 3. extra memory load in that function call.
>
> Pushes us back in terms of performance. I'd suggest to have
> a helper, which is pretty much optimisable and may be coalesced by a compiler with
> adjacent flag checks.
>
> static inline bool io_need_cleanup(unsigned flags)
> {
> return flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED);
> }
>
> if (io_need_cleanup(flags) || (flags & INFLIGHT)) {
> io_clean_op();
> if (INFLIGHT) {}
> }
Sure, we can do that. Particularly because of needing to rearrange
to get it inlined, but no big deal. I'll fiddle it.
--
Jens Axboe
