Re: [PATCH 4/4] udp: memory accounting in IPv4

On Mon, Dec 03, 2007 at 07:14:26PM -0500, Hideo AOKI wrote:

Let me try to use sk_forward_alloc at first, while percpu storage
is an interesting idea.

Actually I don't think sk_forward_alloc would work for UDP because
it runs lockless (unlike TCP which is run under a the socket lock).

So it's either going to be the atomic op or per-cpu counters.  For
me the atomic op isn't the issue, it's the SMP cache-line bouncing
that's more important so having something that did atomic ops on a
socket counter which then feeds into the global counter would solve
my concerns.

But let's wait and see what Dave has to say about this too.

Thanks,
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