[ovs-dev] [xlate 2/2] ofproto: Optimize datapath actions.

Ben Pfaff blp at nicira.com
Wed Jun 1 21:29:29 UTC 2011


On Wed, Jun 01, 2011 at 02:26:11PM -0700, Ethan Jackson wrote:
> > fewer ODP actions, anyhow. ?"fewest" might involve reordering
> > to reduce the number of changes.
> 
> True True, I think this is the fewest possible without reordering the
> output actions, but it is not in fact the fewest possible.
> 
> I changed the commit message to the following:
> 
>     ofproto: Optimize datapath actions.
> 
>     The translation from ofproto to datapath actions has historically
>     been fairly naive.  Since redundant ODP actions result in more code
>     execution in the fast path, this patch changes xlate_actions() to
>     emit fewer ODP actions for a given flow.
> 
>     This change is not simply a theoretical optimization.  It actually
>     reduces the number of ODP actions for real flow tables which
>     Nicira's controllers use in practice.  Furthermore, removing
>     unnecessary modification actions after the last output action has
>     the added benefit of saving a whole sk_clone() in the fast path.

sk_clone() -> skb_clone().

Otherwise looks good, thank you.



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