Which system do you use? Android, Ubuntu, OOWOW or others?
Ubuntu
Which version of system do you use? Khadas official images, self built images, or others?
vim3-ubuntu-20.04-gnome-linux-4.9-fenix-1.1.1-220725-emmc.img, and “apt full-upgrade” last week
Please describe your issue below:
I set up the 4G module according the documentation khadas. I have the network but I found the errors in the log dmesg, and after several hours the network will disconnect and reconnect. And the network speed will be slower. I tried one solution to add “vm.min_free_kbytes = 32768” in “/etc/sysctl.conf”, this delays the occurrence of the error but not permanently solve the problem.
This error occurs immediately when the memory is occupied. Looks a bit like a memory leak in the network.
@ivan.li, I think that this error only occurs when the RAM memory is fully occupied. In the case of free memory, because the network module has a lot of memory available, although there is a “memory leak” problem, we cannot see the error. Did you test with the memory occupied? What is your current kernel version? I try to update to the same version. Thank you.
I tried the version you sent (with the kernel version 4.9.241 after updating), but the error still occurs when the RAM memory is occupied. You can use the command in a tmux session to occupy the memory:
Hello @ivan.li, I need to run an AI inference program which uses most of the memory. While the program is running, it has no effect on the use of other units or other network modules such as Wi-Fi, Ethernet or other 4G USB sticks.
I tried to set “vm.min_free_kbytes = 32768” in “/etc/sysctl.conf”, which forces the kernel’s memory manager to keep at least 32MB of free memory in order to ensure proper functioning of the system itself. The reserved memory will not be allocated to other programs.
In this case, the error with the Quectel 4G module did not appear immediately, but after about 2 days, the error appeared. That is to say, even if the memory does not run out, the memory will be slowly occupied by the 4G module over time.
Just like the previous stress test, we just occupied the memory, not a memory leak or a momory problem, but the 4G module had an error. This is not normal.
I think it’s the driver or kernel who has a memory problem with the 4G module, it gradually fills up the reserved memory. Currently I can only temporarily resolve this error by rebooting. I will do more tests to see where the memory leak is.
Hello @ivan.li, thanks a lot. I wait the test results on your side.
Is it possible to reboot/reset the 4G module without rebooting the vim3? For example by sending AT commands or restart driver or network unit etc. Because we can only temporarily fix this problem by rebooting vim3 each day. It’s inconvenient.