Re: [PATCH 2/2] io_uring/nop: use io_find_buf_node()

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

On 3/1/25 02:21, Jens Axboe wrote:
> On 2/28/25 7:15 PM, Pavel Begunkov wrote:
>> On 3/1/25 01:41, Pavel Begunkov wrote:
>>> On 3/1/25 00:16, Caleb Sander Mateos wrote:
>>>> Call io_find_buf_node() to avoid duplicating it in io_nop().
>>>
>>> IORING_NOP_FIXED_BUFFER interface looks odd, instead of pretending
>>> to use a buffer, it basically pokes directly into internal infra,
>>> it's not something userspace should be able to do.
>>>
>>> Jens, did use it anywhere? It's new, I'd rather kill it or align with
>>> how requests consume buffers, i.e. addr+len, and then do
>>> io_import_reg_buf() instead. That'd break the api though, but would
>>> anyone care?
>>
>> 3rd option is to ignore the flag and let the req succeed.
> 
> Honestly what is the problem here? NOP isn't doing anything that
> other commands types can't or aren't already. So no, it should stay,

It completely ignores any checking and buffer importing stopping
half way at looking at nodes, the behaviour other requests don't
do. We can also add a request that take a lock and releases it
back because other requests do that as well but as a part of some
useful sequence of actions.

> it's been handy for testing overheads, which is why it was added in
> the first place.



-- 
Pavel Begunkov