Re: kern/55663 (Support for EVFILT_USER in kqueue(2))

[Ruslan Nikolaev <nruslan_devel%yahoo.com@localhost>]

Yes, I know that features should be added more sparingly... However, 
this particular one is implemented more than 10 years ago in OS X and 
FreeBSD. And some well-known applications such as nginx and mysql just 
blindly assume it is present (and they are also probably tested more 
when this option enabled as the mysql bug report suggests). It would be 
good to maintain better NetBSD and FreeBSD compatibility if possible. 
And it still does not fundamentally change the interface, unlike epoll 
which would be a totally different story :)

On 10/20/20 8:10 PM, Joerg Sonnenberger wrote:
> The following reply was made to PR kern/55663; it has been noted by GNATS.
>
> From: Joerg Sonnenberger <joerg%bec.de@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc: jnemeth%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
> 	nruslan_devel%yahoo.com@localhost
> Subject: Re: kern/55663 (Support for EVFILT_USER in kqueue(2))
> Date: Wed, 21 Oct 2020 02:05:26 +0200
>
>   On Tue, Oct 20, 2020 at 09:25:01PM +0000, Ruslan Nikolaev wrote:
>   >  1. Why is it needed?
>   >
>   >  Quite a few applications use it. To be specific, please consider Nginx.
>   >  Although, it *does* compile under NetBSD, several critical features are
>   >  missing without EVFILT_USER.
>   
>   That's a strawman. By that reasoning, we should add epoll(2). There is
>   nothing in Nginx that needs it, just that the code currently requires
>   it. That's a big difference.
>   
>   Joerg
>