Re: [RFC] make per interface sysctl entries configurable

[Octavian Purdila <opurdila@ixiacom.com>]

On Sunday 25 October 2009 23:37:19 you wrote:
> Octavian Purdila a écrit :
> > RFC patches are attached.
> >
> > Another possible approach: add an interface flag and use it to decide
> > whether we want per interface sysctl entries or not.
> 
> Hmm, could we speedup sysctl instead, adding rbtree or something ?
> 

Very good point, I think this is the best solution for people using a 
moderately high number of interfaces (a few thousand).

But for really large setups there is another issue: memory consumption. In 
fact, in order to be able to scale to 128K interfaces and still have a 
significant amount of memory available to applications we also had to disable 
sysfs and #ifdef CONFIG_SYSFS struct device from net_device.

I would also argue that when you have such a large number of interfaces you 
don't need to change setting on a per interface basis. Or at least this is our 
case :)  and I suspect that the case with a large number of PPP interfaces is 
similar.