Subject: memory reporting in guest
From: Ghislain Adnet <gadnet@aqueos.com>
Date: Thu, 2 Sep 2021 09:58:24 +0200

hi,

   Just wanted to have a look at memory report in the guest, on a recent test with no
limits on the guest so it owns all the host ram as it is alone on it:

I runned:  free -k ; vserver myguest exec free -k; tail m*usage*; cat /proc/meminfo


               total        used        free      shared  buff/cache   available
Mem:       32899752     8337540      974416       75216    23587796    24016424
Swap:       3903484      386420     3517064

               total        used        free      shared  buff/cache   available
Mem:       32899752    16993004    15439052       75216      467696      704392
Swap:             0           0           0


   swap 0 is normal we do not allow guest to swap. But the used/free/buff-cache/available
difference is quite large. The cgroup usage of the guest is:


==> memory.kmem.max_usage_in_bytes <==
648863744

==> memory.kmem.tcp.max_usage_in_bytes <==
0

==> memory.kmem.tcp.usage_in_bytes <==
0

==> memory.kmem.usage_in_bytes <==
419672064

==> memory.max_usage_in_bytes <==
33245798400

==> memory.memsw.max_usage_in_bytes <==
33689448448

==> memory.memsw.usage_in_bytes <==
18203516928

==> memory.usage_in_bytes <==
17879355392


MemTotal:       32899752 kB
MemFree:          974336 kB
MemAvailable:   24016348 kB
Buffers:          308972 kB
Cached:         22811128 kB
SwapCached:        84452 kB
Active:         21965572 kB
Inactive:        9233376 kB
Active(anon):    6312276 kB
Inactive(anon):  1841792 kB
Active(file):   15653296 kB
Inactive(file):  7391584 kB
Unevictable:          12 kB
Mlocked:              12 kB
SwapTotal:       3903484 kB
SwapFree:        3517064 kB
Dirty:               124 kB
Writeback:             0 kB
AnonPages:       8013512 kB
Mapped:           133524 kB
Shmem:             75216 kB
Slab:             550988 kB
SReclaimable:     467696 kB
SUnreclaim:        83292 kB
KernelStack:        8112 kB
PageTables:        34688 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    20353360 kB
Committed_AS:   11809700 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:     2890700 kB
DirectMap2M:    30547968 kB
DirectMap1G:     2097152 kB


is there any way to be better at this ?

-- 
cordialement,
Ghislain