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From: David Miller <davem@davemloft.net>
Subject: Re: Socket buffer sizes with autotuning
Date: Fri, 16 May 2008 18:29:33 -0700 (PDT)
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From: "Jerry Chu" <hkchu@google.com>
Date: Fri, 16 May 2008 18:13:20 -0700

> The host inflight accounting gets screwed up. It looks like
> pskb_expand_head() called by tcp_tso_acked()->tcp_trim_head() messes
> up the accounting but I don't know how to fix it (still trying to
> understand this complex piece of code). There could be other reason
> as well.

This is just like freeing up a normal SKB, so decrementing the
in_flight value the appropriate number of packets should do the right
thing.

tcp_tso_acked() calculates this adjustment for you, in packets_acked.