Summary
When I start my linux machine it eats about 3.7 Gigs of memory.
By the end of the day, after I close everything I used for work and then close even everything else, even stuff that was actually running in the morning, when it was using 3 Gigs, I have about 9 GiB used, excluding buffers and cache.
Looking at processes doesn't show anything suspicious. The memory is not visibly used by any of them.
-> free -h
total used free shared buff/cache available
Mem: 31Gi 9.1Gi 5.4Gi 78Mi 16Gi 21Gi
Swap: 0B 0B 0B
-> sudo ps --no-headers ax -o rss | awk '{rss += $1} END {print rss}'
3900356
Sum of all processes shows 3.7 GiB - exactly what I would expect, given how it started in the morning.
Memory is really "used" by something, I tried to claim the remaining 21 GiB, and as soon as I fill them up, system becomes unresponsive and I have to restart.
How can I find the missing memory?
Additional info
-> uname -r
5.10.16-1-default
OS: Opensuse Tumbleweed 20210215
DE: KDE Plasma 5.21
freeassudo? – DanieleGrassini Feb 19 '21 at 18:18top? i find it more usefull for such kind of inspection. – DanieleGrassini Feb 19 '21 at 18:40man top. The fields it displays are under your control. – waltinator Feb 19 '21 at 18:48topandhtop, both show numbers that are consistent withfreeandpsand no trace of the owner of the "missing" memory. – Czar Feb 19 '21 at 19:42