Date: Thu, 24 May 2012 23:43:42 +0000 From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> To: Kevin Oberman <kob6558@gmail.com> Cc: net@freebsd.org Subject: Re: Major performance hit with ToS setting Message-ID: <FC59CF19-C3BD-4906-8338-C18AC5DC6867@lists.zabbadoz.net> In-Reply-To: <CAN6yY1sLxFJ18ANO7nQqLetnJiT-K6pHC-X3yT1dWuWGa0VLUg@mail.gmail.com> References: <CAN6yY1sLxFJ18ANO7nQqLetnJiT-K6pHC-X3yT1dWuWGa0VLUg@mail.gmail.com>
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On 24. May 2012, at 22:55 , Kevin Oberman wrote: > When we set the ToS bits for less than best effort (also called > scavenger) on packets (ToS=32), performance on FreeBSD 8.2 is > terrible. It was as good as best effort on FreeBSD 7.3 (assuming no > congestion). I will look into what 9 does, but does anyone have an > idea of why 8.2 behaves so badly when ToS is set to 32? > Here is an example of what happens to performance: > nuttcp with ToS=0: > 622.5000 MB / 1.00 sec = 5221.7570 Mbps > 623.3125 MB / 1.00 sec = 5228.5883 Mbps > 624.0000 MB / 1.00 sec = 5234.4495 Mbps > > With ToS=32 (0x20): > 0.3750 MB / 1.00 sec = 3.1457 Mbps > 0.5000 MB / 1.00 sec = 4.1942 Mbps > 0.5000 MB / 1.00 sec = 4.1942 Mbps > > This is,of course, on a 10G interface. On 7.3 there is little > difference between the two. We are using cubic CC on the 8.2 system. This looks like a different problem than just TOS. I assume however that not setting the TOS you get the same as expected performance? Which NIC? /bz -- Bjoern A. Zeeb You have to have visions! It does not matter how good you are. It matters what good you do!
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