Re: [patch] Real-Time Preemption, -RT-2.6.12-rc1-V0.7.41-01

Magnus Naeslund(t)
2005-03-21T23:16:56Z

Ingo Molnar wrote:
>
> i've uploaded my current tree (-V0.7.41-01) to:
>
> http://redhat.com/~mingo/realtime-preempt/
>
> it includes the latest round of RCU fixes - but doesnt solve the SMP
> bootup crash.
>
> Ingo

With this kernel I can run for some 20 minutes, then the ip_dst_cache
overflows.
I gather it has something to do with RCU...

If I just let it run and grep ip_dst_cache /proc/slab it goes up to 4096
(max) and then the printk's are starting, and the networks stops.
After i up the limit to the double (echo "8192" >
/proc/sys/net/ipv4/route/max_size) network starts to work again.
But of course, after a while it overflows again:

# grep ip_dst_cache /proc/slabinfo
ip_dst_cache 8192 8205 256 15 1 : tunables 16 8
0 : slabdata 547 547 0

I haven't tried the vanilla 2.6.12-rc2 kernel, and I don't have the time
to do that right now, but i figured it would have something to do with
your patch. Older 2.6.8 works just fine.

Regards,
Magnus