Re: [PATCH] Improve behaviour of Netlink Sockets

[jamal <hadi@xxxxxxxxxx>]

On Thu, 2004-09-23 at 08:07, Herbert Xu wrote:
> On Wed, Sep 22, 2004 at 08:08:40AM -0400, jamal wrote:
> >
> > Since netlink is being used for a lot of things now, it may be time to
> > obsolete those assumptions. 
> 
> I'm not against changes.  But so far I haven't seen anything concrete
> about what these new things are yet :)

So lets start by using the following logic:
1) If you made the socket buffers small enough compared to message
size/arrival rate, then an overrun will happen
corrollary:
2) If you made the message size/arrival fast enough relative to socket
size, an overrun will happen

If you agree that #1 is equivalent to #2, then you can experiment by #1
to see the issue.

> > Note also, theres a lot of wastage of that scarce sock buffer via page
> > sized skbs - its not as trivial to fix, but would go some way to improve
> > overrunning of the socket.
> 
> I wasn't aware of this scarcity problem.  Can you elaborate?

The NLM_GOODSIZE allocation done for each netlink skb,
In the case of the dump you dont apriori know how much space you need,
so it is fair. 

cheers,
jamal