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

[John Nemeth <jnemeth%cue.bc.ca@localhost>]

The following reply was made to PR kern/55663; it has been noted by GNATS.

From: John Nemeth <jnemeth%cue.bc.ca@localhost>
To: matthew green <mrg%eterna.com.au@localhost>,
        Ruslan Nikolaev <nruslan_devel%yahoo.com@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: re: kern/55663 (Support for EVFILT_USER in kqueue(2))
Date: Fri, 30 Oct 2020 13:31:24 -0700

 On Oct 30, 20:24, matthew green wrote:
 }
 } just to throw my hat in here as well -
 } 
 } i am interested in a solution for EVFILT_USER support.
 } there are many apps that would benefit from it.  (there
 } are a few more events like directory updates, close,
 } and write in freebsd i'd also like to see added.)
 } 
 } i believe it could live in userspace, and that would be
 } strongly preferably, but unless it's actually compatible
 } with existing implementations (ie, they just start to
 } work without patching beyond "use this freebsd path"),
 } it seems not nearly as useful as it should be.
 
      We've seen cases where libc is bypassed by major things such
 as Rust or Go (I recall one of those having problems due to using
 syscalls directly, but I don't recall which one).  If we're going
 to be compatible with other BSDs then I strongly believe it has to
 be at the syscall level as much as possible and not at the API
 level.  For this reason, I believe that it must go in the kernel.
 
 }-- End of excerpt from matthew green