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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Ward <david.ward@ll.mit.edu>, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] xfrm: Call IP receive handler directly for inbound tunnel-mode packets
Date: Mon, 02 Jan 2012 09:18:02 +0100	[thread overview]
Message-ID: <1325492282.2526.32.camel@edumazet-laptop> (raw)
In-Reply-To: <20120102072828.GA5380@gondor.apana.org.au>

Le lundi 02 janvier 2012 à 18:28 +1100, Herbert Xu a écrit :

> You can't do this as this may cause stack overruns if we nest
> too deeply.
> 

I was considering adding a generic helper, for tunneling,
taking into account the depth for current packet.

[ calling netif_receive_skb() instead of netif_rx(), to solve the OOO
problem occurring on SMP when interrupts are spreaded on several cpus ]


We could use the delta between skb->data and skb->head as an estimation
of this depth, in order not adding a new skb field ?

#define DEPTH_THRESHOLD (NET_SKB_PAD + 64)

static inline void netif_reinject(struct sk_buff *skb)
{
if (skb->data - skb->head < DEPTH_THRESHOLD)
	netif_receive_skb(skb);
else
	netif_rx(skb);
}

  reply	other threads:[~2012-01-02  8:18 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-02  3:32 [PATCH net-next] xfrm: Call IP receive handler directly for inbound tunnel-mode packets David Ward
2012-01-02  7:28 ` Herbert Xu
2012-01-02  8:18   ` Eric Dumazet [this message]
2012-01-03 17:56     ` David Miller
2012-01-02 19:52   ` Ward, David - 0663 - MITLL
2012-01-11  4:45     ` Herbert Xu

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