Subject: Re: [RFC] restore netdev_priv optimization (planb)

From: "Kok, Auke" <[email-masked]>
Date: Fri, 17 Aug 2007 18:21:25 -0700

David Miller wrote:
> From: Stephen Hemminger <[email-masked]>
> Date: Fri, 17 Aug 2007 17:49:09 -0700
> 
>> Fix optimization of netdev_priv() lost by the addition of multiqueue.
>>
>> Only configurations that define MULITQUEUE need the extra overhead in
>> netdevice structure and the loss of the netdev_priv optimization.
>>
>> Signed-off-by: Stephen Hemminger <[email-masked]>
> 
> Every distribution vendor is going to turn MULTIQUEUE on.  Therefore
> %99 of Linux users will not see any gain from your patch.
> 
> You're walking around in a dark room and hitting walls every
> few seconds.  Take a moment and think about how to really deal
> with this generically for a second before churning out another
> patch.
> 
> For example, how about making the multiqueue limit fixed, say at 64
> queues, and declare the egress_queues as an array of 64 entries.  Then
> you can get constant pointer formation for both the netdev priv and
> the queues.

this sounds highly optimistic ("64 queues is enough for everyone"?) and probably 
will be quickly outdated by both hardware and demand...

Auke