From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pablo Neira <pablo@eurodev.net>
Subject: Re: [PATCH]: 1st step to remove skb_linearize() in ip6_tables.c and
 optimization
Date: Wed, 07 Jul 2004 00:59:23 +0200
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Cc: Harald Welte <laforge@netfilter.org>,
 Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>,
  netfilter-devel@lists.netfilter.org,  kisza@securityaudit.hu,
 usagi-core@linux-ipv6.org
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To: Patrick McHardy <kaber@trash.net>
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Hi Patrick,

Patrick McHardy wrote:

> skb_copy_bits is taking about twice as much cycles as tcp_match
> and 20% of total cycles.


AFAIK we are using skb_copy_bits because it walks through fragment list 
in a safe way, I read an old thread (Harald and DaveM discussion) about 
this. If I'm not wrong, that's why this was the method selected when 
conntrack started handling fragments in 2.6 in a different way.

Well, I wonder if we could check if current skb is fragmented (something 
like skb->data_len!=0), in that case use skb_copy_bits, if not walk 
through skb payload directly as we use to do in 2.4 and save that memcpy.

regards,
Pablo