Latency spikes on FreeBSD 8.2 with kernel scan function.

[Alexander V. Chernikov]

On 23.11.2011 19:47, Ondrej Zajicek wrote:
> On Wed, Nov 23, 2011 at 07:25:18PM +0400, Alexander V. Chernikov wrote:
>>> On BSD, kernel scan is implemented by requesting a big buffer and
>>> copying several tens of MB of route data from kernel to BIRD.
>>> I am not an expert on BSD, but perhaps there may be some kernel problem
>>> on some BSD version?
>> This looks much more like some shaper configuration problem. There are
>> no global locks in kernel for entire routing table. And no consumer can
>> hold lock that can be acquired by ISR for such a long time.
>
> You think that BSD kernel applies shaping on sysctl() calls?
> (which is how the table scan is implemented in krt_sysctl_scan() ).
>
No. I think that network traffic shaper (which is configured) shapes ALL 
network traffic including local traffic traveling through loopback 
interface. (I've done similar funny things by mistake in the past)

-- 
WBR, Alexander