Re: [Bridge] Re: [PATCH] (6/6) bridge: receive path optimization

[Stephen Hemminger <shemminger@xxxxxxxx>]

On Thu, 26 May 2005 14:46:38 -0700 (PDT)
"David S. Miller" <davem@xxxxxxxxxxxxx> wrote:

> From: Stephen Hemminger <shemminger@xxxxxxxx>
> Date: Thu, 26 May 2005 11:04:25 -0700
> 
> > This improves the bridge local receive path by avoiding going
> > through another softirq.  The bridge receive path is already being called 
> > from a netif_receive_skb() there is no point in going through another
> > receiveq round trip. 
> > 
> > Recursion is limited because bridge can never be a port of a bridge
> > so handle_bridge() always returns.
> 
> I applied all 6 patches, but this one in particular I'd like
> to comment on.
> 
> Remember all of those bridge netfilter stack usage issues
> we have a few months ago?  This could edge us back into
> those problems again.

no, because the br_frame_finish is called after the netfilter
decision:
        netif_receive_skb
           handle_bridge
               br_handle_frame 
                  br_handle_frame_finish
                     br_pass_frame_up
                        br_pass_frame_up_finish
                           netif_receive_skb  <---- change
                                (normal receive path)

So the call chain is bounded (ie not related to number of filters)
but slightly longer.