Re: [PATCH] Improve behaviour of Netlink Sockets

On Thu, 2004-09-23 at 23:24, Herbert Xu wrote:

There are three possible netlink usages:

1) Request/response:

No overruns should occur.

Cant assume this. A request for an ACK is fine. A get is a different
ball game.

2) Dump:

No overruns should occur because of dump only fills in the next one when
the previous one is taken off the queue by the user.

3) Async messages:

Overruns may occur if the arrival rate exceeds the application's
processing capacity or if the queue is too small for a burst.

Now we were discussing about how we can do congestion control for 3).
But to do that we need to know exactly what these messages are.  For
example if they're coming from an external source as is the case in
ip_queue then you can't congestion control it at all.

Oh and never use the same socket for 1+2) and 3) together.  You can
use the socket for 1) and 2), but 3) must be in its own socket.

I think the discussion to have a mini-slab-like allocator for netlink
that i see going on in other thread is what we need. However, so far
that seems to be only useful for 2).

cheers,
jamal