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From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] tcp: make TCP quick ACK behavior modifiable
Date: Mon, 23 Aug 2010 15:23:30 -0700 (PDT)
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From: Chris Snook <chris.snook@gmail.com>
Date: Mon, 23 Aug 2010 18:19:45 -0400

> Just because we've allowed stupid TCP sysctls in the past does not
> mean we should continue to do so now.  We recently made delayed ack a
> per-route tunable, so consistency would suggest we do the same here.
> Per-route tunables are more flexible, and as with the delayed ack
> patch, there are use cases where that granularity gives a clear
> advantage over a sysctl.  For example, you may want to disable quick
> ack on a high-MTU path and enable it on a low-MTU path.
> 
> If you need a hint for how to implement the per-route tunable, look
> for the delayed ack patch from early 2009.

I completely agree with Chris that this should be a per-route rather
than a global sysctl tunable.