Comment 28 for bug 1852001

I have this problem as well on Cinnamon, so it doesn't appear to be specific to KDE. It stalls often and frequently over 15-30 seconds at a time for no apparent reason. But the swapping to disk may be a clue.

I see this on 5.4.0-40 and have also tried with the lowlatency version of the kernel and it doesn't help.

One thing that seems to reduce the frequency of the problem somewhat is to disable transparent_hugepage support but it still happens even after that.

I have 32GB ram and it starts happening when I get to about 50% ram (mem available) usage. The system also appears to start swapping at that point despite what swappiness is set to. I tried setting it to 10 but it is still swapping at what appears to be ~ 50% usage.

It appears to be very easy to reproduce if you run a few VMware VMs on a system.

# cat /proc/sys/vm/swappiness
10

$ free -m
              total used free shared buff/cache available
Mem: 31030 6591 246 9050 24192 14936
Swap: 32767 4942 27825

$ cat /proc/meminfo

MemTotal: 31774792 kB
MemFree: 256768 kB
MemAvailable: 15324804 kB
Buffers: 5887324 kB
Cached: 16712984 kB
SwapCached: 488276 kB
Active: 19816476 kB
Inactive: 8835508 kB
Active(anon): 12801324 kB
Inactive(anon): 2522936 kB
Active(file): 7015152 kB
Inactive(file): 6312572 kB
Unevictable: 145612 kB
Mlocked: 48 kB
SwapTotal: 33554428 kB
SwapFree: 28493052 kB
Dirty: 2301336 kB
Writeback: 9564 kB
AnonPages: 6161528 kB
Mapped: 7931416 kB
Shmem: 9272240 kB
KReclaimable: 2201904 kB
Slab: 2451272 kB
SReclaimable: 2201904 kB
SUnreclaim: 249368 kB
KernelStack: 21552 kB
PageTables: 85272 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 49441824 kB
Committed_AS: 30098296 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 55400 kB
VmallocChunk: 0 kB
Percpu: 7712 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
FileHugePages: 0 kB
FilePmdMapped: 0 kB
CmaTotal: 0 kB
CmaFree: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 0 kB
DirectMap4k: 5078656 kB
DirectMap2M: 27346944 kB
DirectMap1G: 0 kB