svn commit: r279539 - head/sys/sys

[Neel Natu]

Hi Davide,

On Mon, Mar 2, 2015 at 12:26 PM, Davide Italiano <davide at freebsd.org> wrote:
> 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 A rather outdated (and maybe not completely functional) version of the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.
>

This would be a very welcome improvement.

best
Neel

> --
> Davide
>