netdev - Re: Hight speed data sending from custom IP out of kernel

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Message-ID: <1303734625.2747.121.camel@edumazet-laptop>
Date:	Mon, 25 Apr 2011 14:30:25 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	monstr@...str.eu
Cc:	juice@...gman.org, netdev@...r.kernel.org
Subject: Re: Hight speed data sending from custom IP out of kernel

Le lundi 25 avril 2011 à 14:27 +0200, Eric Dumazet a écrit :
> Le lundi 25 avril 2011 à 14:18 +0200, Michal Simek a écrit :
> 
> > > 
> > > Now, if all you want to do is send many packets from pktgen (with only
> > > ID changing), you could add a fast path to not rebuild from scratch new
> > > packets.
> > 
> > What do you mean?
> 
> 
> If you know your device has X slots in its TX ring buffer, you would
> have to maintain at least X+1 skbs in pktgen to make sure you reuse an
> skb while its previous logical content was sent on wire.
> 
> Then you are free to only change iph->id and iph->check very fast.
> 

Checking skb->users would also be a good way to know if TX completion
released skb reference. If your module owns the last reference, it can
do a recycle.




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