netdev - Re: [PATCH net-next 0/2] tcp: re-add header prediction

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Date:   Wed, 30 Aug 2017 11:20:51 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     fw@...len.de
Cc:     netdev@...r.kernel.org, edumazet@...gle.com
Subject: Re: [PATCH net-next 0/2] tcp: re-add header prediction

From: Florian Westphal <fw@...len.de>
Date: Wed, 30 Aug 2017 19:24:56 +0200

> Eric reported a performance regression caused by header prediction
> removal.
> 
> We now call tcp_ack() much more frequently, for some workloads
> this brings in enough cache line misses to become noticeable.
> 
> We could possibly still kill HP provided we find a different
> way to suppress unneeded tcp_ack, but given we're late in
> the cycle it seems preferable to revert.

Indeed, reverting at this point in the game is the best thing
to do right now.

Applied, thanks.