Message-ID: <Pine.LNX.4.44.0307311003080.16619-100000@localhost.localdomain>
From: "Tomar, Nagendra" <nagendra_tomar@adaptec.com>
Reply-To: "Tomar, Nagendra" <nagendra_tomar@adaptec.com>
To: linux-net@vger.kernel.org
Subject: Avoiding re-ordering in netif_rx()
Date: Thu, 31 Jul 2003 10:11:56 +0530
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I am modifying linux kernel 2.4.18 to add support for our TCP offload 
card. The problem is:
The packets that I get from the card are fully TCP processed and
in-order. 
Now I feed these packets to netif_rx(). marking a flag in the skbuff
which 
says that the full TCP/IP processing is done on this packet and the
higher 
layers can just bypass the packet protocol  processing. On an SMP m/c 
different consequtive in-order packets received from the card can be 
queued to different per-cpu queues and it might so happen that the later

received packet is added to the socket receive queue first ( bcos the 
softirq on the later CPU got a chance to execute first). This
maliciously 
reorders the data.

My question is, what is an elegant way of avoiding this. I have a couple

of choices, but I want to know what people think. f.e one way is to
queue 
these packets to a single queue and not a per-cpu queue. In this case 
order will be honoured.

brilliant suggestions are very welcome !!

Thanx
tomar

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