On Mar 2, 2014, at 4:41 PM, Dave Taht <[email protected]> wrote: > Nice work! > > I have a problem in that I can't remember if target autotuning made it > into that release or not. > > Coulde you do a tc -s qdisc show dev ge00 on your favorite of the > above and paste? I still think > target is still too low on the egress side with the current calculation.
Pasted below. The 14.8 msec is the result of the calculation that comes from the current adapt_target_to_slow_link() function for 830kbps. > Secondly, now that you have a setting you like, trying pie, codel, and > ns2_codel also would be interesting. Need to find another available time slot, but sure. > efq_codel is currently uninteresting. Wasn't clear if you were using > nfq_codel or fq_codel throughout. nfq_codel used for all tests. Rich root@cerowrt:~# tc -s qdisc show dev ge00 qdisc htb 1: root refcnt 2 r2q 10 default 12 direct_packets_stat 0 Sent 122649261 bytes 332175 pkt (dropped 0, overlimits 579184 requeues 0) backlog 0b 0p requeues 0 qdisc nfq_codel 110: parent 1:11 limit 1001p flows 1024 quantum 300 target 14.8ms interval 109.8ms Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 maxpacket 0 drop_overlimit 0 new_flow_count 0 ecn_mark 0 new_flows_len 0 old_flows_len 0 qdisc nfq_codel 120: parent 1:12 limit 1001p flows 1024 quantum 300 target 14.8ms interval 109.8ms Sent 122649261 bytes 332175 pkt (dropped 129389, overlimits 0 requeues 0) backlog 0b 0p requeues 0 maxpacket 0 drop_overlimit 0 new_flow_count 37646 ecn_mark 0 new_flows_len 1 old_flows_len 2 qdisc nfq_codel 130: parent 1:13 limit 1001p flows 1024 quantum 300 target 14.8ms interval 109.8ms Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 maxpacket 0 drop_overlimit 0 new_flow_count 0 ecn_mark 0 new_flows_len 0 old_flows_len 0 qdisc ingress ffff: parent ffff:fff1 ---------------- Sent 278307120 bytes 467944 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 > > > On Sun, Mar 2, 2014 at 1:18 PM, Rich Brown <[email protected]> wrote: >> I took some time this weekend, and ran careful speed and latency tests on >> the CeroWrt 3.10.28-16 build. I have a much better understanding of how all >> this works, both in theory and in practice. Here's an executive summary of >> the overall test procedure with lots of details below. >> >> Adjusting CeroWrt's configured up- and download rates in the SQM page >> affects both the actual data transfer rates as well as the latency. If you >> set the values too low, CeroWrt will enforce that bottleneck, and the >> transfer rates will be lower than you could attain on your link. If you >> configure them too high, though, the transfer rates may look better, but the >> latency can go off the charts. Here's how I arrived at a good balance. >> >> Test Conditions: >> >> - Running tests from my MacBook Pro, 10.9.2. >> - Wi-Fi off; ethernet cable direct to Netgear WNDR3700v2 with CeroWrt >> 3.10.28-16. >> - DSL service from Fairpoint, nominally "7 Mbps down/768kbps up". >> - DSL Modem sync rate (the actual rate that bits enter/leave my house) is >> 7616kbps down; 864kbps up. The line is apparently fairly clean, too. >> - Base ping time to the nearest router at ISP (via traceroute) is 29-30 msec. >> - To minimize other traffic, I turned off most of the computers at home, and >> also quit my mail client (which is surprisingly chatty). >> >> The Tests: >> >> I ran two different tests: netperf-wrapper with the RRUL test, and >> speedtest.net. These give very different views of performance. RRUL really >> stresses the line using multiple simultaneous up and download streams. >> Speedtest.net is a consumer test that only tests one direction at a time, >> and for a short time. We want to look good with both. >> >> For the RRUL tests, I invoked netperf-wrapper like this: netperf-wrapper >> rrul -p all_scaled -l 60 -H atl.richb-hanover.com -t text-shown-in-chart >> For the Speedtest.net tests, I used their web GUI in the obvious way. >> >> For both tests, I used a script (pingstats.sh, see my next message) to >> collect the ping times and give min, max, average, median, and 10th and 90th >> percentile readings. >> >> Test Procedure: >> >> I ran a series of tests starting with the up/down link rates spelled out by >> Sebastian Moeller's amazingly detailed note last week. See >> https://lists.bufferbloat.net/pipermail/cerowrt-devel/2014-February/002375.html >> Read it carefully. There's a lot of insight available there. >> >> The initial configuration was 6089/737 down/up, with the (nearly default) >> values for Queue Discipline (nfq_codel, simple.qos, ECN on for ingress; >> NOECN for egress, auto for both ingress and egress latency targets), and ATM >> link layer with 44 bytes of overhead. >> >> With those initial configuration values, latency was good but the speeds >> were disappointing. I then re-ran the tests with CeroWrt configured for >> higher up/down link speeds to see where things broke. >> >> Things got better and better with increasing link rates until I hit 7600/850 >> - at that point, latency began to get quite large. (Of course, with SQM >> disabled, the latency got dreadful.) >> >> There was an anomaly at 7000/800 kbps. The 90th percentile and max numbers >> jumped up quite a lot, but went *down* for the next test in the sequence >> when I increased the upload speed to 7000/830. I ran the experiment twice to >> confirm that behavior. >> >> I should also note that in the course of the experiment, I re-ran many of >> these tests. Although I did not document each of the runs, the results >> (speedtest.net rates and the pingstats.sh values) were quite consistent and >> repeatable. >> >> Conclusion: >> >> I'm running with CeroWrt 3.10.28-16 configured for down/up 7000/830, >> (nearly) default Queue Discipline and ATM+44 bytes of overhead. With these >> configurations, latency is well in hand and my network is pretty speedy. >> >> We need to figure out how to explain to people what to expect re: the >> tradeoff between "faster speeds" that show up in Speedtest.net (with >> accompanying crappy performance) and slightly slower speeds with a *way* >> better experience. >> >> The data follows... >> >> Rich >> >> ================================================================ >> >> RRUL Tests: The charts associated with these RRUL runs are all available at >> http://richb-hanover.com/rrul-tests-cerowrt-3-10-28-16/ >> >> 6089/737: >> Min: 28.936 10pct: 29.094 Avg: 40.529 Median: 37.961 90pct: 52.636 >> Max: 77.171 Num pings: 77 >> >> 6200/750: >> Min: 28.715 10pct: 29.298 Avg: 41.805 Median: 39.826 90pct: 57.414 >> Max: 72.363 Num pings: 77 >> >> 6400/800: >> Min: 28.706 10pct: 29.119 Avg: 39.598 Median: 38.428 90pct: 52.351 >> Max: 69.492 Num pings: 78 >> >> 6600/830: >> Min: 28.485 10pct: 29.114 Avg: 41.708 Median: 39.753 90pct: 57.552 >> Max: 87.328 Num pings: 77 >> >> 7000/800: >> Min: 28.570 10pct: 29.180 Avg: 46.245 Median: 42.684 90pct: 62.376 >> Max: 169.991 Num pings: 77 >> Min: 28.775 10pct: 29.226 Avg: 43.628 Median: 40.446 90pct: 60.216 >> Max: 121.334 Num pings: 76 (2nd run) >> >> 7000/830: >> Min: 28.942 10pct: 29.285 Avg: 44.283 Median: 45.318 90pct: 58.002 >> Max: 85.035 Num pings: 78 >> Min: 28.951 10pct: 29.479 Avg: 43.182 Median: 41.000 90pct: 57.570 >> Max: 74.964 Num pings: 76 (2nd run) >> >> 7600/850: >> Min: 28.756 10pct: 29.078 Avg: 55.426 Median: 46.063 90pct: 81.847 >> Max: 277.807 Num pings: 84 >> >> SQM Disabled: >> Min: 28.665 10pct: 29.062 Avg: 1802.521 Median: 2051.276 90pct: >> 2762.941 Max: 4217.644 Num pings: 78 >> >> ================================================================ >> >> Speedtest.net: First values are the reported down/up rates in the Speedtest >> GUI >> >> 6089/737: >> 5.00/0.58 >> Min: 28.709 10pct: 28.935 Avg: 33.416 Median: 31.619 90pct: 38.608 >> Max: 49.193 Num pings: 45 >> >> 6200/750: >> 5.08/0.58 >> Min: 28.759 10pct: 29.055 Avg: 33.974 Median: 32.584 90pct: 41.938 >> Max: 46.605 Num pings: 44 >> >> 6400/800: >> 5.24/0.60 >> Min: 28.447 10pct: 28.826 Avg: 34.675 Median: 31.155 90pct: 41.285 >> Max: 81.503 Num pings: 43 >> >> 6600/830: >> 5.41/0.65 >> Min: 28.868 10pct: 29.053 Avg: 35.158 Median: 32.928 90pct: 44.099 >> Max: 51.571 Num pings: 44 >> >> 7000/800: >> 5.73/0.62 >> Min: 28.359 10pct: 28.841 Avg: 35.205 Median: 33.620 90pct: 43.735 >> Max: 54.812 Num pings: 44 >> >> 7000/830: >> 5.74/0.65 (5.71/0.62 second run) >> Min: 28.605 10pct: 29.055 Avg: 34.945 Median: 31.773 90pct: 42.645 >> Max: 54.077 Num pings: 44 >> Min: 28.649 10pct: 28.820 Avg: 34.866 Median: 32.398 90pct: 43.533 >> Max: 69.288 Num pings: 56 (2nd run) >> >> 7600/850: >> 6.20/0.67 >> Min: 28.835 10pct: 28.963 Avg: 36.253 Median: 34.912 90pct: 44.659 >> Max: 54.023 Num pings: 48 >> >> SQM Disabled: >> 6.46/0.73 >> Min: 28.452 10pct: 28.872 Avg: 303.754 Median: 173.498 90pct: 499.678 >> Max: 1799.814 Num pings: 45 >> _______________________________________________ >> Cerowrt-devel mailing list >> [email protected] >> https://lists.bufferbloat.net/listinfo/cerowrt-devel > > > > -- > Dave Täht > > Fixing bufferbloat with cerowrt: > http://www.teklibre.com/cerowrt/subscribe.html _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel
