At seemingly random points in time kwin_x11 freezes the desktop for several seconds, and after that it unfreezes with a notification that compositing was restarted. In the system logs I can see that there was a page allocation failure in the kernel module:
[87398.720448] kwin_x11: page allocation failure: order:4, mode:0x40cc0(GFP_KERNEL|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0
[87398.720453] CPU: 4 PID: 1988 Comm: kwin_x11 Tainted: P OE 5.4.0-48-lowlatency #52-Ubuntu
[87398.720453] Hardware name: System manufacturer System Product Name/P8Z68-V PRO, BIOS 3603 11/09/2012
[87398.720454] Call Trace:
[87398.720467] ? compact_zone_order+0xbb/0xf0
[87398.720468] ? get_page_from_freelist+0x233/0x390
[87398.720490] nvkms_alloc+0x24/0x60 [nvidia_modeset]
[87398.720499] _nv002714kms+0x16/0x30 [nvidia_modeset]
[87398.720501] WARNING: kernel stack frame pointer at 00000000ffcb012a in kwin_x11:1988 has bad value 0000000000000000
I have seen this happen at different times - under CPU load and mostly idle, with a lot of free host memory available.
Note that unlike the problem described in the other topic (440.48.02: Random X.org lock ups due to kernel module crash), in this case it doesn’t happen on waking up or going to sleep (DPMS), and it happens with HardDPMS=False. It also affects KWin instead of Xorg.
This started happening after the upgrade to 455.23.04. I didn’t have this problem with 450 series.
Kubuntu 20.04, x86_64.
nvidia-bug-report.log.gz (280.9 KB)