RE: Scaling problem with a lot of AF_PACKET sockets on differentinterfaces

From: Eric Dumazet
Date: Fri Jun 07 2013 - 09:54:58 EST

On Fri, 2013-06-07 at 14:30 +0100, David Laight wrote:

> Looks like the ptype_base[] should be per 'dev'?
> Or just put entries where ptype->dev != null_or_dev on a per-interface
> list and do two searches?

Yes, but then we would have two searches instead of one in fast path.

ptype_base[] is currently 16 slots, 256 bytes on x86_64.
Presumably the per device list could be a single list, instead of a hash
table, but still...

If the application creating hundred or thousand of AF_PACKET sockets is
a single process, I really question why using a single AF_PACKET was not

We now have a FANOUT capability on AF_PACKET, so that its scalable to
million of packets per second.

I would rather try this way before adding yet another section in

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