svn commit: r279539 - head/sys/sys

[Davide Italiano]

On Mon, Mar 2, 2015 at 12:05 PM, John-Mark Gurney <jmg at freebsd.org> wrote:
> Author: jmg
> Date: Mon Mar  2 20:05:16 2015
> New Revision: 279539
> URL: https://svnweb.freebsd.org/changeset/base/279539
>
> Log:
>   give others fair warning that _SPARE2 isn't just cxgb, but used by large
>   number of other subsystems, so you probably don't want _SPARE2..
>
>   ktr needs an overhaul to really only compile in the ones you want,
>   we've long passed the 31 bits it provides..
>

If you really want to do the overhaul (which would be honestly great),
I might consider revamping my work for per-cpu KTR buffer and include
that in the change. Originally it was just an exercise, but then it
evolved and I've been sitting with it in my local tree for a while. I
never had the chutzpah to upstream it because it involves fundamental
changes and breaks compatibility with the old ktrdump(1) format.
A rather outdated (and maybe not completely functional) version of the
patch can be found here:
http://people.freebsd.org/~davide/locking/ktr_percpu.4.diff , which
should give you an high level view of the change.
I can update it to the last version and bring up for review, if
somebody think it might be a sane idea avoiding synchronization on a
single buffer for KTR.

--
Davide