error finishing read!

I have run the long ping test 3 times. Here are the 3 results for max:
First ping test: 4.2ms 
Second ping test : 3.4ms
Third ping test: 15.9ms

So it didn't get any better.

Above in the attachment I had shown file /etc/network/interfaces.
There I had inserted lines for eth0 as described in man hm2_eth. Do I have to replace eth0 with enp5s0?

Greetings Anton

yes of course

the screenshot you sent, it shows "no_isolcpus". I would try „isolcpus=5.7“ in grub command line. 

Hi unfortunately grub command line doesn't tell me anything. how do i get there and what command do i have to enter there?

edit the grub command boot file

sudo nano /etc/default/grub

Find the line: GRUB_CMDLINE_LINUX_DEFAULT=""
edit to : GRUB_CMDLINE_LINUX_DEFAULT="isolcpus=5,7"

Then save and exit: ctrl+x then press "y" to confirm

sudo update-grub

sudo reboot

Thank you for the information.
I thought it would be more complicated.
If I have understood correctly, then cores 5 to 7 are isolated. But what are these cores used for?
Don't you still have to assign the IRQ from the network card to a core?
I'll try later to see if Chris's instructions lead to an improvement. 

Unfortunately, the behaviour has deteriorated again. After starting LinuxCNC, the finishing read error now appears immediately. The motors can no longer be moved at all. Perhaps this laptop is simply not suitable.
Attached is the histogram and the ping with isolcpus=5.7.

I have installed LinuxCNC on 3 computers so far. 
1) Laptop i7: Very good latency times, very poor ping times - > unusable
2) Esprimo Q956 Mini PC with i5: poor latency, good ping - > unusable
3) DELL Optiplex 7010 Mini PC with Intel Celeron G2030 (by far the weakest processor): good latency, good ping (see appendix) -> usable
 
So the worst of the 3 processors is the best for real-time Linux in terms of latency and ping!!!???
So it must also be due to the mainboard, possibly the memory, ... !?

sunny greetings

 

Most common cause of really terrible network latency
(ping times > 1 ms) is power management setup

Pining the IRQ can help if you are close but if you have 4 ms ping times
the host most likely has power management/speed switching still enabled