svn commit: r353129 - in head/sys: kern sys

[Kyle Evans]

On Sat, Oct 5, 2019 at 4:52 PM Kyle Evans <kevans at freebsd.org> wrote:
>
> Author: kevans
> Date: Sat Oct  5 21:52:06 2019
> New Revision: 353129
> URL: https://svnweb.freebsd.org/changeset/base/353129
>
> Log:
>   Remove the remnants of SI_CHEAPCLONE
>
>   SI_CHEAPCLONE was introduced in r66067 for use with cloned bpfs. It was
>   later also used in tty, tun, tap at points. The rough timeline for being
>   removed in each of these is as follows:
>
>   - r181690: bpf switched to use cdevpriv API by ed@
>   - r181905: ed@ rewrote the TTY later to be mpsafe
>   - r204464: kib@ removes it from tun/tap, declaring it unused
>
>   I've not yet been able to dig up any other consumers in the intervening 9
>   years. It is no longer set on any devices in the tree and leaves an
>   interesting situation in make_dev_sv where we're ok with the device already
>   being set SI_NAMED.
>

I guess a follow-up question to the list... do we consider
SI_CHEAPCLONE imperative to keep around in stable/ branches? It hasn't
been used in head for years, and I'd guess downstream projects don't
intentionally use it either.

I don't care enough to axe it, but I'd like to MFC my newdev() change
since that was driven by some plans to use make_dev_s in if_tuntap...
newdev will need a slight ~2 line addition in stable if SI_CHEAPCLONE
sticks around.

Thanks,

Kyle Evans