svn commit: r284343 - in stable: 10/sys/kern 10/sys/sys 9/sys/kern 9/sys/sys

[John Baldwin]

On 6/14/15 6:39 AM, Oliver Pinter wrote:
> On Sat, Jun 13, 2015 at 6:15 PM, John Baldwin <jhb at freebsd.org> wrote:
> 
> Hi John!
> 
> Could you please MFC this commit too:
> 
> commit 4331ca7813ee01d1745c6ff2ced7030329586b30
> Author: jhb <jhb at FreeBSD.org>
> Date:   Fri May 22 11:09:41 2015 +0000
> 
>     Expand ktr_mask to be a 64-bit unsigned integer.
> 
>     The mask does not really need to be updated with atomic operations and
>     the downside of losing races during transitions is not great (it is
>     not marked volatile, so those races are pretty wide open as it is).
> 
>     Differential Revision:      https://reviews.freebsd.org/D2595
>     Reviewed by:        emaste, neel, rpaulo
>     MFC after:  2 weeks

Hmm, I might not get too it in the near future.  The only reason I've
hesitated to do so is that it does slightly break the in-kernel ABI in
that 'ktr_mask' is a public symbol to kernel modules.  (I've used it in
various hackish tests where I would clear ktr_mask to 0 when some unusual
event happened so that the KTR trace buffer contained the events leading
up to the unusual event.)  OTOH, this is a bit of a special case, so I'm
not sure if this is part of the ABI that we really have to worry about.

-- 
John Baldwin