On 11/24/22 19:29, Jens Axboe wrote:
On 11/24/22 12:17?PM, 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??? #
Doubled checked here, and you're actually right:
55bc: 94000000 bl 4760 <io_cq_unlock_post>
Huh, that's very odd that it doesn't inline it. It doesn't even it I
mark it inline, __always_inline gets it done.
That's odd as well for a function of this size
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.
Doesn't seem to be inlined here either. Compiler:
gcc (Debian 12.2.0-9) 12.2.0
__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.
io_submit_flush_completions() doesn't get inlined,
__io_submit_flush_completions() gets inlined in
io_submit_flush_completions().
Then the compiler is drunk. It doesn't inline the function
explicitly marked inline but does it for a non-inline one.
Unless it's PGO'ed I can't think of a sane reason for it.
--
Pavel Begunkov
