Re: [PATCH 0/2]: Remote softirq invocation infrastructure.

[David Miller <davem@davemloft.net>]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Sun, 21 Sep 2008 15:05:45 +0900

> Unfortunately doing this with IPsec is going to be non-trivial
> since we still want to maintain packet ordering inside IPsec
> and you don't get the inner flow information until you decrypt
> the packet.

Steffen has mechanisms by which to deal with this in his patches.

> So if we want to process IPsec packets in parallel it's best to
> implement that from within the crypto API where we can queue the
> result in order to ensure proper ordering.

That's another option, of course.  And crypto could use remote
softirqs even for that :-)

> Of course, we need to balance any effort spent on this with the
> likelihood that hardware improvements will soon make this obsolete
> (for IPsec anyway).

True, but old hardware will always exist.

A lot of very reasonable machines out there will benefit from software
RX flow seperation.