Re: Kernel panic: Route cache, RCU, possibly FIB trie.

[Dipankar Sarma <dipankar@in.ibm.com>]

On Tue, Mar 21, 2006 at 04:37:19PM +0100, Eric Dumazet wrote:
> Jesper Dangaard Brouer a écrit :
> >There is definitly high memory pressure on this machine!
> >Slab memory usage, range from 39Mb to 205Mb (at the moment on the 
> >production servers).
> >
> 
> Did you tried 2.6.16 ?
> 
> It contains changes in kernel/rcupdate.c so that not too many RCU elems are 
> queued (force_quiescent_state()). So in the case a rt_cache_flush is done, 
> you have the guarantee all entries are not pushed into rcu at once.

Well, memory pressure or not, the oopses shouldn't be happening :)
Perhaps we should look at them before we work around memory
pressure through the rcu batch tuning stuff in 2.6.16 ?

One of the oopses looked like the rcu callback function pointer 
getting corrupted indicating that it was double freed or
problem with RCU itself.

Thanks
Dipankar