Re: [PATCH] io_uring: kill io_cqring_ev_posted() and __io_cq_unlock_post()

[Pavel Begunkov <asml.silence@gmail.com>]

On 11/24/22 19:17, Pavel Begunkov wrote:
> On 11/24/22 18:46, Jens Axboe wrote:
>> On 11/24/22 9:16?AM, Pavel Begunkov wrote:
>>> On 11/21/22 14:52, Jens Axboe wrote:
>>>> __io_cq_unlock_post() is identical to io_cq_unlock_post(), and
>>>> io_cqring_ev_posted() has a single caller so migth as well just inline
>>>> it there.
>>>
>>> It was there for one purpose, to inline it in the hottest path,
>>> i.e. __io_submit_flush_completions(). I'll be reverting it back
>>
>> The compiler is most certainly already doing that, in fact even
> 
> .L1493:
> # io_uring/io_uring.c:631:     io_cq_unlock_post(ctx);
>      movq    %r15, %rdi    # ctx,
>      call    io_cq_unlock_post    #

wrong one,

__io_submit_flush_completions:
	pushq	%rbp	#
...
.L1793:
# io_uring/io_uring.c:1394: 	io_cq_unlock_post(ctx);
	movq	%r12, %rdi	# ctx,
	call	io_cq_unlock_post	#


> Even more, after IORING_SETUP_CQE32 was added I didn't see
> once __io_fill_cqe_req actually inlined even though it's marked
> so.
> 
>> __io_submit_flush_completions() is inlined in
>> io_submit_flush_completions() for me here.
> 
> And io_submit_flush_completions is inlined as well, right?
> That would be quite odd, __io_submit_flush_completions() is not
> small by any means and there are 3 call sites.
> 

-- 
Pavel Begunkov