svn commit: r289279 - in head/sys: kern vm

[Eric van Gyzen]

On 10/29/2015 15:25, Tijl Coosemans wrote:
> On Wed, 14 Oct 2015 02:10:07 +0000 (UTC) Jeff Roberson <jeff at FreeBSD.org> wrote:
>> Author: jeff
>> Date: Wed Oct 14 02:10:07 2015
>> New Revision: 289279
>> URL: https://svnweb.freebsd.org/changeset/base/289279
>>
>> Log:
>>   Parallelize the buffer cache and rewrite getnewbuf().  This results in a
>>   8x performance improvement in a micro benchmark on a 4 socket machine.
>>   
>>    - Get buffer headers from a per-cpu uma cache that sits in from of the
>>      free queue.
>>    - Use a per-cpu quantum cache in vmem to eliminate contention for kva.
>>    - Use multiple clean queues according to buffer cache size to eliminate
>>      clean queue lock contention.
>>    - Introduce a bufspace daemon that attempts to prevent getnewbuf() callers
>>      from blocking or doing direct recycling.
>>    - Close some bufspace allocation races that could lead to endless
>>      recycling.
>>    - Further the transition to a more modern style of small functions grouped
>>      by prefix in order to improve growing complexity.
> 
> I have an i386 system that locks up easily after this commit.  Booting
> into single user and running make installkernel triggers it consistently.

I can't help you debug this, but I noticed a follow-up commit that fixed
an uninitialized pointer introduced by this commit:

	https://svnweb.freebsd.org/changeset/base/290155

Pending comments from more enlightened folk, you might try updating to
that rev (if you can do so without a lockup...).

Eric