From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Mon, 14 Apr 2014 22:40:45 +0000 Subject: Re: Problem with HTB bandwidth slicing when using TCP traffic Message-Id: <534C63ED.60402@gmail.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Dave Taht wrote: > On Sun, Apr 13, 2014 at 12:43 PM, Andy Furniss > wrote: > At rates below 3Mbit fq_codel needs a bit a tweaking we've > discovered, basically it helps to have a "target" parameter > the > cost of a single MTU's packet - e.g at 1Mbit, we tend to use a target > of 15 and an interval of 150, .5mbit 30, 300. Above 4mbit target and > interval are fine with the defaults. > > Changing the default quantum helps also at rates below 40Mbit - we > use 300. Interesting info, thanks. > For way more detail on how this stuff works, > > http://www.bufferbloat.net/projects/cerowrt/wiki/Wondershaper_Must_Die Hmm, while I agree policers are often crap and wondershaper should have died or at least had the glaring htb misconfiguration fixed, the author went incommunicado so it didn't happen. To be fair to him, htb wasn't even in kernel at the time so it was just a port of the CBQ script - I assume this is the reason. It's a bit strange that the script is critically commented, is not vanilla wondershaper (extra class thus making the configuration error worse), but there is no mention of it. "It" being that rates on htb leafs are not limited by the parent, so when all classes are loaded it's way over the line rate. As for fq_codel - it's good, but it wouldn't tempt me to bung my interactive in with bulk.