I know, there are plenty of "Linux eat my RAM" threads all over the internet, but they can't help me to solve my problem.
(I had a try with this question on askubuntu but I'm off-chart with Mint)
At home my workstation is a Mint19/Ubuntu18.04/Cinnamon box, used for Java/BigData development.
Some time, not every day, after some hours of work, my Intellij IDE becomes laggy, due to missing RAM.
If I look the "top", I see that only some Mo of the 16G RAM are available and that system is swapping.
I can't understand where the +10G RAM are used for. Some time ago, this happened. To have a better understanding, I CTRL-F1 to a non graphical sessions, then I stopped the LightDM X-Server.
So all the RAM eating graphical apps (skype, slack, chrome etc...) are off. And only the system daemons are alive. After this purge "free" gives me :
Mem: 16130044 11507836 3615496 704 1006712 4287260
Swap: 15625212 541820 15083392
So, the XServer stop made me recover ~4G, but 11G are always missing /proc/meminfo looks like :
MemTotal: 16130044 kB
MemFree: 3613360 kB
MemAvailable: 4285680 kB
Buffers: 109512 kB
Cached: 744668 kB
SwapCached: 31984 kB
Active: 433228 kB
Inactive: 492328 kB
Active(anon): 39192 kB
Inactive(anon): 32920 kB
Active(file): 394036 kB
Inactive(file): 459408 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 15625212 kB
SwapFree: 15083392 kB
Dirty: 220 kB
Writeback: 0 kB
AnonPages: 66456 kB
Mapped: 75056 kB
Shmem: 704 kB
Slab: 583976 kB
SReclaimable: 153108 kB
SUnreclaim: 430868 kB
KernelStack: 8624 kB
PageTables: 16852 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 23690232 kB
Committed_AS: 3990300 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
CmaTotal: 0 kB
CmaFree: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 8152580 kB
DirectMap2M: 8331264 kB
DirectMap1G: 1048576 kB
Missing RAM is not in SLAB (there are some threads about that)
I tried several things :
- various versions of sync; echo 3 > /proc/sys/vm/drop_caches
- kernel upgrade (actually on 4.15.0-173)
- Rootkit analysis...
But nothing helped
Any idea ?
Asked by Franck Lefebure
(11 rep)
Apr 26, 2022, 11:44 AM