Re: [net-next v2 1/1] tipc: improve link resiliency when rps is activated

[David Miller <davem@davemloft.net>]

From: Jon Maloy <jon.maloy@ericsson.com>
Date: Wed, 8 Nov 2017 09:59:26 +0100

> Currently, the TIPC RPS dissector is based only on the incoming packets'
> source node address, hence steering all traffic from a node to the same
> core. We have seen that this makes the links vulnerable to starvation
> and unnecessary resets when we turn down the link tolerance to very low
> values.
> 
> To reduce the risk of this happening, we exempt probe and probe replies
> packets from the convergence to one core per source node. Instead, we do
> the opposite, - we try to diverge those packets across as many cores as
> possible, by randomizing the flow selector key.
> 
> To make such packets identifiable to the dissector, we add a new
> 'is_keepalive' bit to word 0 of the LINK_PROTOCOL header. This bit is
> set both for PROBE and PROBE_REPLY messages, and only for those.
> 
> It should be noted that these packets are not part of any flow anyway,
> and only constitute a minuscule fraction of all packets sent across a
> link. Hence, there is no risk that this will affect overall performance.
> 
> Acked-by: Ying Xue <ying.xue@windriver.com>
> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>

Applied, thanks.