Hello!
> so i guess supporting at least scatter/gather
> should give some performance improvements in order to get rid of
> skb_linearize() on xmit?
I beg pardon but before strating to fight problems, it is necessary
to force kernel to prepare something different of linear skbs. :-)
What's about checksumming? Do you plan to ignore it?
> since transmission is done completely by the
> local cpu, all of F_SG/FRAGLIST/HIGHDMA look relatively easy to
> implemement to me.=20
I see no connection between "cpu locality" and frgamtn hadling at all.
> frag_list seems to be the list involved with keeping track of ip
> fragmentation. so dev->hard_start_xmit() with frag_list set would only
> happen on routers or when??
In stock kernels: _never_. Packets are not defragmented by routers,
and netfilter linearizes everything in any case.
Anyway, if the driver is able to provide some facility, why not to do this?
> when is nr_frags>0? i've found some postings indicating sendfile(2) will
> benefit here. is this the only case?
Yes.
Which means that the task is not so sexy. :-)
Alexey
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This archive was generated by hypermail 2b29 : Mon Dec 31 2001 - 21:00:20 EST