From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Thu, 20 May 2004 11:13:37 +0000 Subject: Re: [LARTC] HTB MPU Message-Id: <40AC92E1.2060109@dsl.pipex.com> List-Id: References: <40A37E1B.8060604@dsl.pipex.com> In-Reply-To: <40A37E1B.8060604@dsl.pipex.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Jason Boxman wrote: > On Monday 17 May 2004 18:36, Andy Furniss wrote: > > >>Could be this then - >> >>You can make HTB more accurate by setting HTB_HYSTERESIS to 0 in >>net/sched/sch_htb.c. >> > > > I have been messing with producing graphs with SNMP, so I only just did this. > I was hoping to get before and after graphs to verify any changes, but I > finally just did it. I was just thinking about making ping graphs with sed/xplot myself. Is it easy with SNMP? > > Lucky for me, my ADSL line died tonight, so when it came back up I was able to > see my ping on a completely idle link. Using HTB with HTB_HYSTERESIS set to > 0 appears to have greatly reduced my ping time. It still skips up more often > than when the link is completely idle, but it appears to be (without any > graphs to verify) a marked improvement. (Now I see more 75ms and an > occasional 145ms instead of the complete reverse.) Good - there is another timing tweak I should have mentioned which you may or may not be able to use. http://www.docum.org/stef.coene/qos/faq/cache/40.html I use this - but still notice some things (not TC related) use 100hz. When I finally finish my LFS setups I am going to try and tweak this aswell. > > 68/70/75 out of 20 ICMP packets when idle. > 68.3/91.6/215.7 ms out of 323 ICMP packets at 85% utilization. Assuming there is only upstream traffic for the test that still seems high - but then I don't know what your pinging - my first hop is usually OK. What is the best min you can get pinging your first hop with an empty line - with and without traffic control in use. TC it's self doesn't seem to affect my best empty line rates. At 85% you should see max around 70-80 assuming 25ms baseline pings. > > From the comments in sch_htb.c I take it I just traded speed for accuracy in > some of HTB's calculations, which on such a slow link is probably not an > issue? > Yes. Andy. _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/