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From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net-next] tcp: RFC6298 supersedes RFC2988bis
Date: Sun, 15 Apr 2012 12:48:09 -0400 (EDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 15 Apr 2012 17:40:06 +0200

> 3) use RCU and dont hold parent socket lock to allow parallelism for
> multiqueue NICS (or RPS ...)

This part could be tricky.

We have to be careful in the case that one cpu comes in and finds the
listner sock for a particular child, meanwhile another cpu progresses
that child socket into ESTABLISHED state.  Most of the parent locking
and strict synchronization is there to make sure this case works out
properly.