netdev - Re: [PATCH] Implementation of the sendgroup() system call

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Message-ID: <20090504095300.GF23223@one.firstfloor.org>
Date:	Mon, 4 May 2009 11:53:00 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Avi Kivity <avi@...hat.com>
Cc:	Andi Kleen <andi@...stfloor.org>, Elad Lahav <elahav@...terloo.ca>,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH] Implementation of the sendgroup() system call

> >My guess it's more the copies than the calls? It sounds like
> >you want sendfile() for UDP. I think that would be a cleaner solution
> >than such a specific hack for your application. It would
> >have the advantage of saving the first copy too and be 
> >truly zero copy on capable NICs.
> >  
> 
> An aio udp send could accomplish both multiple packets per call, and 

AIO sockets are a lot of work. There have been various attempts
over the years, but they are very difficult. This was mostly
for TCP -- possibly UDP would be a bit easier -- but still
many complications. It would also need a lot of changes and
you would need to convince the network maintainers that they
are a good idea.

> >Or perhaps simple send to a local multicast group and let
> >some netfilter module turn that into regular UDP.
> >  
> 
> Sounds hacky and rooty.

rooty? Everyone can send to all directions anyways.

It wouldn't be perfect, but quite usable as a short term solution
for a production server.


-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
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