netdev - Re: [PATCH net-next-2.6] pktgen: Optionally leak kernel memory

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Date:	Sun, 25 Jul 2010 10:27:52 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	David Miller <davem@...emloft.net>
Cc:	greearb@...delatech.com, netdev@...r.kernel.org
Subject: Re: [PATCH net-next-2.6] pktgen: Optionally leak kernel memory

Le samedi 24 juillet 2010 à 21:35 -0700, David Miller a écrit :
> From: Eric Dumazet <eric.dumazet@...il.com>
> Date: Sat, 24 Jul 2010 16:13:15 +0200
> 
> > I am not sure David will accept the patch !
> 
> I don't think I can apply this, sorry :-)

Absolutely.

It might be possible for pktgen to use a pool of prebuilt pages to avoid
the cost of clearing pages. This wont work for skb without frags, unless
we change skb_release_data() (it calls kfree(skb->head), I dont think we
can trap this one...)

One better idea would be to take an extra reference on skb before giving
it to transmit, and maintain a list of skbs to recycle once their
refcount hits 1 (our reference). We could avoid most of the skb
setup/freeing costs (no more memory allocations/freeing)

I'll take a look after my vacations, unless someone motivated enough
beats me of course :)

Thanks !

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