From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next-2.6] pktgen: speedup fragmented skbs
Date: Tue, 25 Jan 2011 18:47:33 +0100
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Cc: David Miller <davem@davemloft.net>, netdev <netdev@vger.kernel.org>
To: Ben Greear <greearb@candelatech.com>
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Le mardi 25 janvier 2011 =C3=A0 09:22 -0800, Ben Greear a =C3=A9crit :
> On 01/25/2011 09:13 AM, Eric Dumazet wrote:
> > We spend lot of time clearing pages in pktgen.
> > (Or not clearing them on ipv6 and leaking kernel memory)
> >
> > Since we dont modify them, we can use one zeroed page, and get
> > references on it. This page can use NUMA affinity as well.
> >
> > Define pktgen_finalize_skb() helper, used both in ipv4 and ipv6
>=20
> Some devices, like vlans, can change the skb, but perhaps they
> will not actually mess with the paged data?

Yes, its absolutely forbidden to write on paged data.

If necessary, a COW must be done.