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From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH v2] net: avoid the unnecessary kmalloc
Date: Tue, 30 Nov 2010 09:16:49 +0100
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Cc: "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org
To: Changli Gao <xiaosuo@gmail.com>
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Le mardi 30 novembre 2010 =C3=A0 15:45 +0800, Changli Gao a =C3=A9crit =
:

> I don't think it is a good idea, If it is, why not use
> ksize(skb->head) to set the tail pointer of skb when allocating a new
> skb.
>=20

Calling ksize() for all allocated skb would be overkill, since most of
them are correctly sized and dont need expand() at all.

In what situation do you notice this being expand_head() ever called ?


> If we do sth. like this, more cache lines maybe involved.
>=20

This has same number of _touched_ cache lines actually, and this is wha=
t
matters.

Actually I dont have strong feeling, this is a detail.