Re: [PATCH] io-wq: expose IO_WQ_ACCT_* enumeration items to UAPI

[Jens Axboe]

On 9/12/21 4:24 PM, Dmitry V. Levin wrote:
> On Sun, Sep 12, 2021 at 12:29:41PM -0600, Jens Axboe wrote:
>> On 9/12/21 6:24 AM, Eugene Syromiatnikov wrote:
>>> These are used to index aargument of IORING_REGISTER_IOWQ_MAX_WORKERS
>>> io_uring_register command, so they are to be exposed in UAPI.
>>
>> Not sure that's necessary, as it's really just a boolean values - is
>> the worker type bounded or not. That said, not against making it
>> available for userspace, but definitely not IO_WQ_ACCT_NR. It
>> should probably just go in liburing, I guess.
> 
> If IO_WQ_ACCT_* were just boolean values, no enum would have been
> introduced in the first place.  What's the benefit of hiding
> the API in the implementation, or burying it inside liburing?

Because it's easier to grok internally with an enum instead of
using 0/1. And you could argue that's the case too for an app,
and as I said, I'm not against making them exposed, but the _NR
part is strictly internal.

Just add separate defines or an enum in io_uring.h:

enum {
	IO_WQ_BOUND,
	IO_WQ_UNBOUND,
};

and be done with it.

-- 
Jens Axboe