From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id E267921F1F7 for ; Fri, 23 Aug 2013 12:38:12 -0700 (PDT) Received: from hms-beagle-2.home.lan ([79.229.225.62]) by mail.gmx.com (mrgmx001) with ESMTPSA (Nemesis) id 0Mdren-1VR1hM04on-00PauM for ; Fri, 23 Aug 2013 21:38:09 +0200 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 6.5 \(1508\)) From: Sebastian Moeller In-Reply-To: Date: Fri, 23 Aug 2013 21:38:10 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <9A9B094D-CA07-48B0-85FE-FA7C759FEDE3@gmx.de> References: <56B261F1-2277-457C-9A38-FAB89818288F@gmx.de> <2148E2EF-A119-4499-BAC1-7E647C53F077@gmx.de> <03951E31-8F11-4FB8-9558-29EAAE3DAE4D@gmx.de> To: Dave Taht X-Mailer: Apple Mail (2.1508) X-Provags-ID: V03:K0:OsJJA5OeGIZIjaH6JOWLvEBBRA4xEw+BL0YARo/01J5hTiVqTFK QEqRXFFAJlKZ2xnp/+bSfv1UOqFIL/5jNpD5gmsJcq7hLOnvdSBfuoQKFyz7uy9FfkDvyXx ltJT7E7/1gZl5Zz5dhr0hZKX67xllRxBZw3fbaDK0Z8FzESg51S+xGDpeLGfSXMP5xNlgag 6uGS/P/uwFYv2wxuMN+5A== Cc: Jesper Dangaard Brouer , "cerowrt-devel@lists.bufferbloat.net" Subject: Re: [Cerowrt-devel] some kernel updates X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Aug 2013 19:38:13 -0000 Hi Dave, On Aug 23, 2013, at 07:13 , Dave Taht wrote: >=20 >=20 >=20 > On Thu, Aug 22, 2013 at 5:52 PM, Sebastian Moeller = wrote: > Hi List, hi Jesper, >=20 > So I tested 3.10.9-1 to assess the status of the HTB atm link layer = adjustments to see whether the recent changes resurrected this feature. > Unfortunately the htb_private link layer adjustments still is = broken (RRUL ping RTT against Toke's netperf host in Germany of ~80ms, = same as without link layer adjustments). On the bright side the tc_stab = method still works as well as before (ping RTT around 40ms). > I would like to humbly propose to use the tc stab method in = cerowrt to perform ATM link layer adjustments as default. To repeat = myself, simply telling the kernel a lie about the packet size seems more = robust than fudging HTB's rate tables. Especially since the kernel = already fudges the packet size to account for the ethernet header and = then some, so this path should receive more scrutiny by virtue of having = more users? >=20 > It's my hope that the atm code works but is misconfigured. You can = output the tc commands by overriding the TC variable with TC=3D"echo tc" = and paste here. So I went for TC=3D"logger tc" and used log read to harvest as I = could not find the echo output, but I guess that should not matter. So = here is the result (slightly edited to get rid of the log timestamps and = log level): tc qdisc del dev ge00 root tc qdisc add dev ge00 root handle 1: htb default 12 tc class add dev ge00 parent 1: classid 1:1 htb quantum 1500 rate = 2430kbit ceil 2430kbit mpu 0 linklayer adsl overhead 40 mtu 2047 tc class add dev ge00 parent 1:1 classid 1:10 htb quantum 1500 rate = 2430kbit ceil 2430kbit prio 0 mpu 0 linklayer adsl overhead 40 mtu 2047 tc class add dev ge00 parent 1:1 classid 1:11 htb quantum 1500 rate = 128kbit ceil 810kbit prio 1 mpu 0 linklayer adsl overhead 40 mtu 2047 tc class add dev ge00 parent 1:1 classid 1:12 htb quantum 1500 rate = 405kbit ceil 2366kbit prio 2 mpu 0 linklayer adsl overhead 40 mtu 2047 tc class add dev ge00 parent 1:1 classid 1:13 htb quantum 1500 rate = 405kbit ceil 2366kbit prio 3 mpu 0 linklayer adsl overhead 40 mtu 2047 tc qdisc add dev ge00 parent 1:11 handle 110: fq_codel limit 600 noecn = quantum 300 tc qdisc add dev ge00 parent 1:12 handle 120: fq_codel limit 600 noecn = quantum 300 tc qdisc add dev ge00 parent 1:13 handle 130: fq_codel limit 600 noecn = quantum 300 tc filter add dev ge00 parent 1:0 protocol all prio 999 u32 match ip = protocol 0 0x00 flowid 1:12 tc filter add dev ge00 parent 1:0 protocol ip prio 1 handle 1 fw = classid 1:11 tc filter add dev ge00 parent 1:0 protocol ip prio 2 handle 2 fw = classid 1:12 tc filter add dev ge00 parent 1:0 protocol ip prio 3 handle 3 fw = classid 1:13 tc filter add dev ge00 parent 1:0 protocol ipv6 prio 4 handle 1 fw = classid 1:11 tc filter add dev ge00 parent 1:0 protocol ipv6 prio 5 handle 2 fw = classid 1:12 tc filter add dev ge00 parent 1:0 protocol ipv6 prio 6 handle 3 fw = classid 1:13 tc filter add dev ge00 parent 1:0 protocol arp prio 7 handle 1 fw = classid 1:11 tc qdisc del dev ge00 handle ffff: ingress tc qdisc add dev ge00 handle ffff: ingress tc qdisc del dev ifb0 root tc qdisc add dev ifb0 root handle 1: htb default 12 tc class add dev ifb0 parent 1: classid 1:1 htb quantum 1500 rate = 15494kbit ceil 15494kbit tc class add dev ifb0 parent 1:1 classid 1:10 htb quantum 1500 rate = 15494kbit ceil 15494kbit prio 0 tc class add dev ifb0 parent 1:1 classid 1:11 htb quantum 1500 rate = 32kbit ceil 5164kbit prio 1 tc class add dev ifb0 parent 1:1 classid 1:12 htb quantum 1500 rate = 2582kbit ceil 15430kbit prio 2 tc class add dev ifb0 parent 1:1 classid 1:13 htb quantum 1500 rate = 2582kbit ceil 15430kbit prio 3 tc qdisc add dev ifb0 parent 1:11 handle 110: fq_codel limit 1000 ecn = quantum 500 tc qdisc add dev ifb0 parent 1:12 handle 120: fq_codel limit 1000 ecn = quantum 1500 tc qdisc add dev ifb0 parent 1:13 handle 130: fq_codel limit 1000 ecn = quantum 1500 tc filter add dev ifb0 parent 1:0 protocol all prio 999 u32 match ip = protocol 0 0x00 flowid 1:12 tc filter add dev ifb0 protocol ip parent 1:0 prio 1 u32 match ip tos = 0x00 0xfc classid 1:12 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 2 u32 match ip6 = priority 0x00 0xfc classid 1:12 tc filter add dev ifb0 protocol ip parent 1:0 prio 3 u32 match ip tos = 0x20 0xfc classid 1:13 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 4 u32 match ip6 = priority 0x20 0xfc classid 1:13 tc filter add dev ifb0 protocol ip parent 1:0 prio 5 u32 match ip tos = 0x10 0xfc classid 1:11 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 6 u32 match ip6 = priority 0x10 0xfc classid 1:11 tc filter add dev ifb0 protocol ip parent 1:0 prio 7 u32 match ip tos = 0xb8 0xfc classid 1:11 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 8 u32 match ip6 = priority 0xb8 0xfc classid 1:11 tc filter add dev ifb0 protocol ip parent 1:0 prio 9 u32 match ip tos = 0xc0 0xfc classid 1:11 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 10 u32 match ip6 = priority 0xc0 0xfc classid 1:11 tc filter add dev ifb0 protocol ip parent 1:0 prio 11 u32 match ip tos = 0xe0 0xfc classid 1:11 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 12 u32 match ip6 = priority 0xe0 0xfc classid 1:11 tc filter add dev ifb0 protocol ip parent 1:0 prio 13 u32 match ip tos = 0x90 0xfc classid 1:11 tc filter add dev ifb0 protocol ipv6 parent 1:0 prio 14 u32 match ip6 = priority 0x90 0xfc classid 1:11 tc filter add dev ifb0 parent 1:0 protocol arp prio 15 handle 1 fw = classid 1:11 tc filter add dev ge00 parent ffff: protocol all prio 10 u32 match u32 = 0 0 flowid 1:1 action mirred egress redirect dev ifb0 I notice it seem this only shows up for egress(), but looking at = simple.qos ingress() is not addend ${ADSLL} at all so that is to be = expected. There is nothing in dmesg at all. So I am off to add ADSLL to ingress() as well and then test RRUL = again... Jesper please let me know if this looks reasonable, at least to my eye = it seems to fit with what "tc disc add htb help" tells me. I tried your: echo "func __detect_linklayer +p" = /sys/kernel/debug/dynamic_debug/control but got no output even though debugs was already mounted=85 Best=20 Sebastian > =20 > Now, I have been testing this using Dave's most recent cerowrt = alpha version with a 3.10.9 kernel on mips hardware, I think this kernel = should contain all htb fixes including commit 8a8e3d84b17 (net_sched: = restore "linklayer atm" handling) but am not fully sure. >=20 > It does.=20 > =20 > `@Dave is there an easy way to find which patches you applied to the = kernels of the cerowrt (testing-)releases? >=20 > Normally I DO commit stuff that is in testing, but my big push this = time around was to get everything important into mainline 3.10, as it = will be the "stable" release for a good long time.=20 > =20 > So I am still mostly working the x86 side at the moment. I WAS kind of = hoping that everything I just landed would make it up to 3.10. But for = your perusal: >=20 > http://snapon.lab.bufferbloat.net/~cero2/patches/3.10.9-1/ has most of = the kernel patches I used in it. 3.10.9-2 has the ipv6subtrees patch = ripped out due to another weird bug I'm looking at. (It also has support = for ipv6 nat thx to the ever prolific stephen walker heeding the call = for patches...). 100% totally untested, I have this weird bug to figure = out how to fix next: >=20 > = http://lists.alioth.debian.org/pipermail/babel-users/2013-August/001419.ht= ml >=20 > I fear it's a comparison gone south, maybe in bradley's optimizations = for not kernel trapping, don't know. >=20 > 3.10.9-2 also disables dnsmasq's dhcpv6 in favor of 6relayd. I HATE = losing the close naming integration, but, had to try this.... >=20 > If you guys want me to start committing and pushing patches again, = I'll do it, but most of that stuff will end up in 3.10.10, I think, in a = couple days. The rest might make 3.12. Pie has to survive scrutiny on = the netdev list in particular. >=20 > While I have you r attention :) I also tested 3.10.9-1's pie and it is = way better than 3.10.6-1's (RRUL ping RTTs around 110 ms instead of = 3000ms) but still worse than fq_codel (ping RTTs around 40ms with proper = atm link layer adjustments). >=20 > This is with simple.qos I imagine? Simplest should do better than that = with pie. Judging from how its estimator works I think it will do badly = with multiple queues. But testing will tell... >=20 > But, yea, this pie is actually usable, and the previous wasn't. Thank = you for looking at it! >=20 > It is different from cisco's last pie drop in that it can do ecn, does = local congestion notification, has a better use of net_random, it's = mostly KernelStyle, and I forget what else. >=20 > There is still a major rounding error in the code, and I'd like cisco = to fix the api so it uses identical syntax to codel. Right now you = specify "target 8" to get "target 7", and the "ms" is implied. target 5 = becomes target 3. The default target is a whopping 20 (rounded to 19), = which is in part where your 70+ms of extra delay came from.=20 >=20 > Multiple parties have the delusion that 20ms is "good enough". >=20 > Part of the remaining delay may also be rounding error. Cisco uses = kernels with HZ=3D1000, cero uses HZ=3D250..... >=20 > Anyway, to get more comparable tests... you can fiddle with the two = $QDISC lines in simple*.qos to add a target 8 to get closer to a codel = 5ms config, but that would break a codel config which treats target 8 as = target 8us. >=20 > I MIGHT, if I get energetic enough, fix the API, the time accounting, = and a few other things in pie, the problem is, that ns2_codel seems = still more effective on most workloads and *fq_codel smokes absolutely = everything. There are a few places where pie is a win over straight = codel, notably on packet floods. And it may well be easier to retrofit = into existing hardware fast path designs.=20 >=20 > I worry about interactions between pie and other stuff. It seems = inevitable at this point that some form of pie will be widely deployed, = and I simply haven't tried enough traffic types and RTTs to draw a firm = conclusion, period. Long RTTs are the last big place where codel and pie = and fq_codel have to be seriously tested.=20 >=20 > ns2_codel is looking pretty good now, at the shorter RTTs I've tried. = A big problem I have is getting decent long RTT emulation out of netem = (some preliminary code is up at github)=20 >=20 > ... and getting cero stable enough for others to actually use - next = up is fixing the userspace problems.=20 >=20 > ... and trying to make a small dent in the wifi problem along the way = (couple commits coming up) >=20 > ... and find funding to get through the winter. > =20 > There's probably a few other things that are on that list but I = forget. Oh, yea, since the aqm wg was voted on to be formed, I decided I = could quit smoking. > =20 > While I am not able to build kernels, it seems that I am able to = quickly test whether link layer adjustments work or not. SO aim happy to = help where I can :) >=20 > Give pie target 8 and target 5 a shot, please? ns2_codel target 3ms = and target 7ms, too. fq_codel, same.... > =20 > tc -s qdisc show dev ge00 > tc -s qdisc show dev ifb0 >=20 > would be useful info to have in general after each test. >=20 > TIA. >=20 > There are also things like tcp_upload and tcp_download and = tcp_bidirectional that are useful tests in the rrul suite. >=20 > Thank you for your efforts on these early alpha releases. I hope = things will stablize more soon, and I'll fold your aqm stuff into my = next attempt this weekend. >=20 > This is some of the stuff I know that needs fixing in userspace: >=20 > * TODO readlink not found > * TODO netdev user missing > * TODO Wed Dec 5 17:14:46 2012 authpriv.error dnsmasq: found already = running DHCP-server on interface 'se00' refusing to start, use 'option = force 1' to override > * TODO [ 18.480468] Mirror/redirect action on > [ 18.539062] Failed to load ipt action > * upload and download are reversed in aqm > * BCP38 > * Squash CS values > * Replace ntp > * Make ahcp client mode > * Drop more privs for polipo > * upnp > * priv separation > * Review FW rules > * dhcpv6 support > * uci-defaults/make-cert.sh uses a bad path for px5g > * Doesn't configure the web browser either >=20 >=20 >=20 >=20 > Best > Sebastian >=20 >=20 >=20 >=20 > --=20 > Dave T=E4ht >=20 > Fixing bufferbloat with cerowrt: = http://www.teklibre.com/cerowrt/subscribe.html