Date: Wed, 6 Sep 2017 17:13:19 -0700 From: Russell Haley <russ.haley@gmail.com> To: Chris Gordon <freebsd@theory14.net> Cc: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: Beaglebone Black + FreeBSD + USB WiFi = WAP? Message-ID: <CABx9NuTTewBiuesSxWsWsJg2HeRZFPeNU1WSRpqxEALxSUEhkw@mail.gmail.com> In-Reply-To: <E1992F2B-236D-467C-AAEE-B81A59EB1138@theory14.net> References: <40EA308E-489D-4A0B-B75A-2CA5A4EC474E@theory14.net> <685d0eed3532a34f239e7ff893f817db@bakulin.de> <EB1907C8-7A0A-4D45-AD21-B449DC4C0D7D@theory14.net> <CABx9NuQCrspSzcdXh0_cbO1QmexwQbrk1djaGyvKTp370AtxYA@mail.gmail.com> <CABx9NuQJWot9xgs1QtzJ87NfgZM=FPhZ%2B2a-RewDonvGG5LLKg@mail.gmail.com> <CABx9NuT1n8ZYPrZTB8vT2sBmT3U75E4UFgAGA3ZOPTotpsUWeg@mail.gmail.com> <CABx9NuQB=xBNt6%2BX=YKw4XVW5u1XysW%2Bo7pqO_9D2RC%2BF6bKug@mail.gmail.com> <20170905141711.6545490.14963.31294@gmail.com> <656A5193-7389-476C-AF58-EB013E9155F3@theory14.net> <CABx9NuQtXRbN6YPihotuLSnE5cFG-xvRRNYyFSLGxZNPBnKTKQ@mail.gmail.com> <E1992F2B-236D-467C-AAEE-B81A59EB1138@theory14.net>
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On Wed, Sep 6, 2017 at 3:30 PM, Chris Gordon <freebsd@theory14.net> wrote: > Russ, > >> Have you monitored your system on a serial console or direct console >> (i.e. via hdmi/keyboard)? Is the system still responding to other >> commands after you run the speed test? My thought is that the really >> really low bandwidth belies a kernel panic on the main terminal that >> you are not seeing. > > I have a serial console connected the entire time along with ssh sessions= (via wired NIC) into the BBB. There is no panic other other messages on t= he console. The devices remains responsive to user input/actions via ssh. = In a previous reply to my initial inquiry, Ilya Bakulin asked about output = from "top -Sa=E2=80=9D thinking the CPU was overwhelmed. The system stays = at >90% idle through the entire test (upload and download). I see 2-4% WCP= U for interrupts and 1-2% for USB. Good, thanks for clarifying. >> If you would like to do some further testing, you could perhaps help >> me answer these things: > > It won=E2=80=99t be until next week when I can look at any of these. I= =E2=80=99m one of the organizers at vBSDcon and will be at the Dev Summit a= nd conference through the weekend. If anyone is interested, I=E2=80=99m ha= ppy to bring my BBB there for debugging/testing on site. Argh! I was just in Maryland and we flew home from Dulles!!! I made the client push the date forward to last week so I could be home for Labour Day. Have fun! (sob, sob, sob). ;) >> - Can you find a command line way of measuring throughput and latency >> separately that can be run on a host and on the bbb? I'm sure there >> are lots of ways to do so. I will leave it up to you to decide and >> will adopt the same tests so we can compare results. > > I just have to find another device -- I have everything wired here other = than i-devices. I used nuttcp for testing the wired connection, so I would= plan to use that for the Wifi. nuttcp. Got it, I'll start playing with it. >> - Can you run the bbb as a standard device (not an access point) and >> test the performance of the wlan0 interface using the method of >> measurement pointed above? I will do the same at some point with my >> wi-fi dongle. > > Yes, that should be easy to do, but will be next week before I have a cha= nce. > >> Some tests I would like to do: >> - Get DTrace involved as a debugging tool. I have rudimentary DTrace >> skills but will need to consult my books on how to measure throughput >> and latency. There are some examples early in the DTrace book of >> logging system calls made by a process and I will review that again >> when time permits. >> - Run the system through the kernel debugger. I think this is going to >> be difficult though as pausing the kernel in the middle of TCP traffic >> might invalidate any results I get. I know how difficult it can be to >> debug threaded applications, I can't see a kernel being any easier. ;) > > I was thinking along the same lines and hampered only by lack of time and= specific knowledge of what to start poking (of course, this is a great wqy= to learn!). My random thought of the day is that the "down/receive" from eth0 to wlan0 is working somewhat correctly, but the "up/send" from wlan0 to eth0 is causing issues. This is coming from your throughput notes, and the fact I got a whole page downloaded, but received a panic when I was trying to request another page. My thought is to start looking at the send commands for wlan0 and USB. > Thanks for your help. I=E2=80=99ll get some info as soon as I can. Anyt= hing important I=E2=80=99ll add to the bug report. Thanks for having a fun problem to play with! Good luck with the conference and don't worry about time, I have 3 other things that I started this week alone. Anyone want to test a prototype Lua database? lolz. Russ
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