Why L4T/Jetson linux uses a lot of ram? spaicaly /lib/systemd/systemd-udevd

I don’t think this is normal and it uses way too much ram and total ram is only 6.7GiB due to jetpack 5.0 bug

but l4t linux uses a lot ram also happened on jetpack 4.6.1 4.5
even 8GiB is far from enough

I’d be more concerned about how much CPU it consumes, but it does seem like there is a problem. It’s hard to say from that what’s going on, but you might want to view it in tree mode and see what all is running under udevd since it basically just triggers other scripts. Maybe it is a child process and not udevd itself.

I’m not sure if this will help, but it looks like when systemd-udevd is highlighted (not in tree mode), then the hot key “l” should list open files. If there is an open script file it might name it. You might want to type in the list of open files in this thread since screenshots are hard to follow.

most i think is due to zram
but after i disabled zram still use much (screenshot are after diasabled zram)
and i dont need zram (big swap on pcie4.0 ssd is good enough for a linux pc


It is still using a lot of CPU. Not sure what to say for that, but it isn’t normal. If you can list the tree view, then it might list sub-processes.

didn’t i list sub-processes?
see first screenshot

or beacause my ax210 have issue with bluetooth?
dmesg always get spamed

The first lists open files. I’m looking for tree view. The F5 key should toggle that in htop.

Yes, that device is crashing and reloading continuously and is the cause. Manufacturer ID 8087 with device ID 0032 is the Intel bluetooth. Try unplugging it from USB.

that is not usb device
that is ax210 wifi card
wifi works with one workaround
but Bluetooth not

You may try low-light LXDE on Xavier NX. Please refer to
Save 1GB of Memory! Use LXDE on your Jetson - JetsonHacks

Why gnome and Ubuntu 20.04 on 8GB RAM pc uses not so much ram and cpu?
And how to fix Bluetooth issue?

The sample rootfs is for reference. It may not fit your requirement and you can do customization. May try LXDE. Or disable X11 and use DRM.

For the issue about bluetooth, do you observe the same failure with the included wifi/bt module? By default there is a module at key E slot. Probably it is something wrong in driver of ax210 and you may try the default module as a reference.

Wi-Fi card comes with jetson Xavier nx
Wifi function won’t work at all (on jetpack 5.0)
Can’t connect to any wifi (at least ax210 with rename file workaround wifi can work and 2.4Gbps and WPA3 works fine)

is at E key slot
and ax210 driver should come with linux 5.10 and higher

It seems the bluetooth driver is likely interfering with the wifi driver. Note that the m.2 key e has USB, and possibly (probably?) the bluetooth is USB, although drivers could still interfere even if the bluetooth is not USB. One of the problems of the screenshot without an actual log is that there is no way to tell which failed first…bluetooth or wifi.

My thought is that the drivers are doing something to cause USB to repetitively block, and since this has not been an issue before, the only new hardware/driver makes it likely to be an issue with the bluetooth driver.

wifi didn’t fail
it works up to 2.4Gbps
only bluetooth failed

I can’t quote the error I see in the screenshot, but basically each time the bluetooth has an issue the USB of the WiFi also does a disconnect/reconnect. The difference is that the USB does not give an error, so as it reconnects it continues to function, but that isn’t the same as no error…it just works around the issue if it works. I have no way to say what the actual error is, but I suspect that if there is no bluetooth, then the USB of WiFi would not repeatedly disconnect and reconnect. I am confused though that “wifi didn’t fail” since earlier it was mentioned that it only works with 2.4 GHz (you said Gbps, but I am assuming you meant frequency band and not data rate). Perhaps the interaction between bluetooth and WiFi is what causes a need to use only 2.4 GHz? Don’t know.

I strongly suspect there are issues between drivers. If the Intel device has firmware associated with it, then perhaps the firmware needs update. If not, then the only next test I know of is to see if the WiFi’s USB stops disconnect/reconnect behavior for the WiFi when bluetooth is removed. This would verify the interaction between the two.

it is Gbps not Ghz
wifi 6 supports up to 2.4Gbps at 5Ghz 160Mhz