Subject: Re: RTL8169 hw IP4CSUM_Tx workaround
To: Izumi Tsutsui <firstname.lastname@example.org>
From: Manuel Bouyer <email@example.com>
Date: 10/26/2006 17:53:39
On Thu, Oct 26, 2006 at 11:12:15PM +0900, Izumi Tsutsui wrote:
> > > - There are quite few packets which require padding.
> > It depends on the workload I guess.
> Could you take any statistics on real machiens?
> I wonder what type of application will require such packets
> since on my macppc (mostly client) there are only less than
> 0.01% short packets on TX.
Lots of TCP ACK for example.
> > > - Such zeroed memory for padding has to be allocated by
> > > bus_dmamem_alloc(9) and it wastes resouces only for rare packets.
> > > (though most drivers have some room for padding in thier DMA descriptor
> > > structures)
> > It's only 64 bytes, and only one time (you don't need one per interface)
> But it also requires bus_dmamap_create() and bus_dmamap_load() calls
> which may consume some more resources and they are never freed.
Yes, but only once for the life of the system.
Manuel Bouyer <firstname.lastname@example.org>
NetBSD: 26 ans d'experience feront toujours la difference