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From: David Miller <davem@davemloft.net>
Subject: Re: Socket buffer sizes with autotuning
Date: Mon, 12 May 2008 15:31:14 -0700 (PDT)
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From: David Miller <davem@davemloft.net>
Date: Mon, 12 May 2008 15:29:00 -0700 (PDT)

> Simply notice, when we're about to decrement in_flight, that the data
> reference is one.  You can take appropriate actions if so.

Actually, there is an even simpler solution.  Since this is a fast
clone, when the parent SKB is freed we can see if the fast-clone child
is active and has the in_flight atomic_t pointer.  If so, we decrement
in_flight and zap it to NULL.