From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net-next-2.6] net: sk_add_backlog() take rmem_alloc
 into account
Date: Tue, 27 Apr 2010 14:43:07 -0700 (PDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 27 Apr 2010 22:21:02 +0200

> [PATCH net-next-2.6] net: sk_add_backlog() take rmem_alloc into account
> 
> Current socket backlog limit is not enough to really stop DDOS attacks,
> because user thread spend many time to process a full backlog each
> round, and user might crazy spin on socket lock.
> 
> We should add backlog size and receive_queue size (aka rmem_alloc) to
> pace writers, and let user run without being slow down too much.
> 
> Introduce a sk_rcvqueues_full() helper, to avoid taking socket lock in
> stress situations.
> 
> Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp
> receiver can now process ~200.000 pps (instead of ~100 pps before the
> patch) on a 8 core machine.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

This looks great, applied, thanks Eric!