#linuxcnc-devel Logs

Dec 22 2022

10:06 AM roguish[m]: good morning all. anyone know what error this is? what caused it? how to prevent it?
10:14 AM * roguish[m] uploaded an image: (12KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/dRnZzkmpOOeTvpzTyRzMlDTl/read%20error.png >
10:14 AM Tom_L: happen alot?
10:14 AM Tom_L: try increasing the servo thread is all i can think of but pcw may have an actual answer
10:14 AM rmu: roguish[m]: udp network packet got dropped
10:16 AM roguish[m]: pcw-home: that would explain why the board stops working.
10:16 AM roguish[m]: how to prevent? i believe it's a realtek nic. it's on board an Arock md
10:16 AM roguish[m]: motherboard.
10:16 AM roguish[m]: Asrock Q1900M
10:17 AM pcw-home: Not sure if this is the broken RTK driver or what
10:17 AM pcw-home: what do ping times show?
10:18 AM pcw-home: Also is this with a 1 ms servo thread period?
10:18 AM roguish[m]: yes. 1ms
10:19 AM roguish[m]: 64 bytes from 10.10.10.10: icmp_seq=3 ttl=64 time=0.116 ms
10:20 AM roguish[m]: Linux Force60 5.10.0-20-rt-amd64 #1 SMP PREEMPT_RT Debian 5.10.158-2 (2022-12-13) x86_64 GNU/Linux
10:21 AM roguish[m]: debian 11.6
10:26 AM pcw-home: sudo chrt 99 ping -i .001 10.10.10.10 -q
10:27 AM pcw-home: for a few minutes
10:28 AM roguish[m]: OK, running
10:29 AM roguish[m]: I think I have a 4.19 linux-image installed. I could boot to it and see what happens.
10:30 AM pcw-home: most of the Ethernet latency issues are with post 4.x kernels
10:31 AM Tom_L: have you tested 6.0 yet?
10:31 AM pere: running 'ifconfig' and looking at error count might be useful.
10:33 AM Tom_L: 6.0.5 rt patch is available
10:34 AM Tom_L: dunno if anyone has tried 6 yet
10:36 AM roguish[m]: here's what I have available with the current repositories
10:36 AM * roguish[m] uploaded an image: (182KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/bSasYJrAzKvQvTPFHVVqcJPQ/image.png >
10:37 AM roguish[m]: pcw-home: should I kill the ping? with control C ?? or how?
10:39 AM Tom_L: that's a Q1900M running 64 bit bullseye?
10:39 AM Tom_L: i have that board i think
10:40 AM roguish[m]: Tom_L: yes
10:41 AM Tom_L: not sure what pc it's in..
10:41 AM roguish[m]: it's my desk test system
10:42 AM roguish[m]: pcw-home: [sudo] password for noel:... (full message at <https://libera.ems.host/_matrix/media/v3/download/libera.chat/d9b0dd8b7ffaecb7cd8e085a7b3ea537c1077fa4>)
10:43 AM Tom_L: as is mine
10:43 AM Tom_L: i thought it might be on the mill
10:44 AM * roguish[m] uploaded an image: (101KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/FRguUxOgUjDEBnRjtCpXSHsV/image.png >
10:44 AM roguish[m]: pere
10:45 AM roguish[m]: Ok, going to reboot to 4.19 back in just a minute...
10:45 AM Tom_L: i considered building 6 to test it but haven't yet
10:46 AM pere: roguish[m]: and 10.10.10.11 is the driver interface?
10:46 AM pere: roguish[m]: in any case, no error packages, so the problem is not the driver knowing it is throwing away packages.
10:47 AM rmu: it may also be something "benign" like a defective cable
10:48 AM rmu: but then there should be errors
10:48 AM pcw-home: yes, stop the ping with control C
10:49 AM roguish[m]: pcw-home: results are above here a few posts....
10:50 AM roguish[m]: i'm back...
10:51 AM pere: roguish[m]: are you aware of 'mtr' to run combined ping and traceroute with error calculations?
10:51 AM Tom_L: how often do you get the error?
10:51 AM roguish[m]: booted into 4.19.0-9
10:52 AM roguish[m]: Tom_L: on this system, frequently. I'm testing my boards, and just noticed the error popping up, and the 7i80 test going from good to fail.
10:53 AM Tom_L: so you should be able to find it if it's frequent
10:53 AM roguish[m]: running the ping thing again.....
10:55 AM roguish[m]: pere: no. I am willing to learn, as you know.... what is it?
10:57 AM pere: you know traceroute and ping already, right. mtr is a combination tool, kind of like the merge of both
10:58 AM roguish[m]: pere: I don't seem to have that command. what package is it in. I will install it.
10:59 AM Tom_L: https://www.redhat.com/sysadmin/linux-mtr-command
10:59 AM Tom_L: love the cable...
10:59 AM roguish[m]: installing now
11:00 AM pere: the package is named mtr in debian.
11:01 AM pere: I normally use mtr-tiny, as I do not care about the X window version.
11:01 AM pcw-home: roguish max ping 67 ms!
11:03 AM Tom_L: took a coffee break on that one
11:03 AM roguish[m]: pcw-home: guess that's not too good....
11:04 AM Tom_L: you've checked the bios settings?
11:05 AM roguish[m]: yes. shut down everything non-essential
11:06 AM roguish[m]: pcw-home: sudo chrt 99 ping -i .001 10.10.10.10 -q... (full message at <https://libera.ems.host/_matrix/media/v3/download/libera.chat/ce197777846985e7ce91ca57b1ac34ff4bddd6d4>)
11:06 AM roguish[m]: looks better..... doh
11:07 AM Tom_L: 1ms servo thread?
11:07 AM Tom_L: getting pretty close to that on the max number
11:07 AM Tom_L: .. not sure how all that works but doesn't sound great to me
11:08 AM CaptHindsight[m]: you need older kernels for older Intel due to their lying and crappy lack of security processors for lower latency
11:09 AM CaptHindsight[m]: newer kernels are full of fixes for their crap and are bloated
11:12 AM pcw-home: Pretty much all of the Intel patches are in 4.19
11:13 AM pcw-home: they slow things down but do not have a major effect on latency
11:14 AM CaptHindsight[m]: seems vary with which Intel hardware you test
11:14 AM CaptHindsight[m]: we have little intel hardware here and noticed the trend a while ago
11:14 AM pcw-home: The 67 ms thing is probably either a RTK driver bug or simply a broken Debian "RT" kernel
11:17 AM pcw-home: The 4.X vs later network latency issue affects AMD as well
11:23 AM CaptHindsight[m]: seems that some i5's behave well with Debian RT kernels
11:24 AM CaptHindsight[m]: maybe people should be aware of that and stick with those for Intel if they feel the urge to still support Intel
11:24 AM CaptHindsight[m]: but they desreve what they pay for
11:24 AM roguish[m]: OK, linuxcnc has been running for about 20 minutes now on 4.19, and now errors....
11:25 AM CaptHindsight[m]: s/desreve/deserve/
11:47 AM pcw-home: now errors or no errors?
11:48 AM roguish[m]: pcw-home: no errors.... fat finger typing...
11:49 AM pcw-home: Yes, many Debian RT kernels seem to have network specific latency issues
11:50 AM pcw-home: The 6.x kernels are better (but not as good as 4.19)
12:23 PM seb_kuzminsky: roguish[m]: are you using the isolcpu kernel command-line argument to reserve a CPU for linuxcnc realtime stuff? and are you affining the irq handlers for the nic to the same cpu?
12:27 PM roguish[m]: seb_kuzminsky: no isolcpu on my test setup. cannot recall about my mill setup. not sure what you mean about the irq handlers. yes, I know what irq's are, just not handlers for the nic.
12:27 PM roguish[m]: and thanks for checking in.
04:37 PM -!- #linuxcnc-devel mode set to +v by ChanServ
05:58 PM JT-Cave: hmm w is no where near o