Bug: Erroneous Memusage

[orhnk]

I have 2x8Gb's of ram on my desktop.

With that being said, I assume total memory usage should be lesser than 16Gb.

But ps_mem shows me some numbers above that range:

screencast.mp4

[pixelb]

Can you provide the text output from ps_mem to give some indication of the potential over-counting.
Also pertinent /proc/$pid/smaps_rollup files could be useful

[zen2]

I think I got the same behavior, total ps_mem ram usage is far superior to free ram usage:

 Private  +   Shared  =  RAM used	Program

124.0 KiB + 154.0 KiB = 278.0 KiB	init
140.0 KiB + 142.0 KiB = 282.0 KiB	acpid
204.0 KiB + 282.0 KiB = 486.0 KiB	rngd
380.0 KiB + 466.0 KiB = 846.0 KiB	chronyd
392.0 KiB + 492.0 KiB = 884.0 KiB	crond
564.0 KiB + 634.0 KiB =   1.2 MiB	pure-ftpd
536.0 KiB + 698.0 KiB =   1.2 MiB	master
664.0 KiB + 874.0 KiB =   1.5 MiB	nrpe
700.0 KiB +   1.1 MiB =   1.7 MiB	qmgr
900.0 KiB + 912.0 KiB =   1.8 MiB	agetty (6)
868.0 KiB +   1.2 MiB =   2.1 MiB	tlsmgr
  1.1 MiB +   1.1 MiB =   2.2 MiB	udevd
  1.8 MiB +   2.2 MiB =   4.1 MiB	opendkim
  1.4 MiB +   3.1 MiB =   4.5 MiB	showq
  1.2 MiB +   4.1 MiB =   5.4 MiB	bash (2)
  2.1 MiB +   5.7 MiB =   7.8 MiB	sshd (3)
 16.4 MiB +  17.4 MiB =  33.8 MiB	syslog-ng (2)
 22.8 MiB + 139.4 MiB = 162.2 MiB	php-fpm (5)
804.3 MiB + 806.3 MiB =   1.6 GiB	mysqld
  2.5 GiB +   2.6 GiB =   5.1 GiB	apache2 (5)
---------------------------------
                          6.9 GiB
=================================

              total        used        free      shared  buff/cache   available
Mem:           11Gi       3.4Gi       1.3Gi       802Mi       6.9Gi       7.1Gi
Swap:          63Mi          0B        63Mi

=== apache2 ====

5654eb0f8000-7ffdf07fb000 ---p 00000000 00:00 0                          [rollup]
Rss:             1288464 kB
Pss:             1277647 kB
Pss_Anon:        1276302 kB
Pss_File:           1101 kB
Pss_Shmem:           243 kB
Shared_Clean:       7400 kB
Shared_Dirty:       5848 kB
Private_Clean:         0 kB
Private_Dirty:   1275216 kB
Referenced:      1287080 kB
Anonymous:       1280212 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
5654eb0f8000-7ffdf07fb000 ---p 00000000 00:00 0                          [rollup]
Rss:                8632 kB
Pss:                3511 kB
Pss_Anon:           3253 kB
Pss_File:            258 kB
Pss_Shmem:             0 kB
Shared_Clean:       2376 kB
Shared_Dirty:       4052 kB
Private_Clean:         0 kB
Private_Dirty:      2204 kB
Referenced:         2800 kB
Anonymous:          6256 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
5654eb0f8000-7ffdf07fb000 ---p 00000000 00:00 0                          [rollup]
Rss:              641236 kB
Pss:              630470 kB
Pss_Anon:         629143 kB
Pss_File:           1082 kB
Pss_Shmem:           243 kB
Shared_Clean:       7312 kB
Shared_Dirty:       5884 kB
Private_Clean:         0 kB
Private_Dirty:    628040 kB
Referenced:       639788 kB
Anonymous:        633072 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
5654eb0f8000-7ffdf07fb000 ---p 00000000 00:00 0                          [rollup]
Rss:              778696 kB
Pss:              767933 kB
Pss_Anon:         766555 kB
Pss_File:           1134 kB
Pss_Shmem:           243 kB
Shared_Clean:       7336 kB
Shared_Dirty:       5852 kB
Private_Clean:        40 kB
Private_Dirty:    765468 kB
Referenced:       777292 kB
Anonymous:        770468 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
5654eb0f8000-7ffdf07fb000 ---p 00000000 00:00 0                          [rollup]
Rss:               13492 kB
Pss:                3130 kB
Pss_Anon:           1941 kB
Pss_File:           1065 kB
Pss_Shmem:           124 kB
Shared_Clean:       6636 kB
Shared_Dirty:       6308 kB
Private_Clean:       104 kB
Private_Dirty:       444 kB
Referenced:        13112 kB
Anonymous:          6268 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB

=== mysqld ====

564587bd1000-7ffc8a1d2000 ---p 00000000 00:00 0                          [rollup]
Rss:              829620 kB
Pss:              824706 kB
Pss_Anon:         808788 kB
Pss_File:          15918 kB
Pss_Shmem:             0 kB
Shared_Clean:       6016 kB
Shared_Dirty:          0 kB
Private_Clean:     14816 kB
Private_Dirty:    808788 kB
Referenced:       829556 kB
Anonymous:        808788 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB

=== php-fpm ====

55def7fa4000-7fff73114000 ---p 00000000 00:00 0                          [rollup]
Rss:               70652 kB
Pss:               35558 kB
Pss_Anon:           8107 kB
Pss_File:           4155 kB
Pss_Shmem:         23295 kB
Shared_Clean:      12624 kB
Shared_Dirty:      50652 kB
Private_Clean:         0 kB
Private_Dirty:      7376 kB
Referenced:        67928 kB
Anonymous:         11544 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
55def7fa4000-7fff73114000 ---p 00000000 00:00 0                          [rollup]
Rss:               78512 kB
Pss:               43402 kB
Pss_Anon:          11254 kB
Pss_File:           4244 kB
Pss_Shmem:         27903 kB
Shared_Clean:      12664 kB
Shared_Dirty:      50648 kB
Private_Clean:        68 kB
Private_Dirty:     15132 kB
Referenced:        75808 kB
Anonymous:         14688 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
55def7fa4000-7fff73114000 ---p 00000000 00:00 0                          [rollup]
Rss:                5048 kB
Pss:                1221 kB
Pss_Anon:           1220 kB
Pss_File:              0 kB
Pss_Shmem:             1 kB
Shared_Clean:          4 kB
Shared_Dirty:       4884 kB
Private_Clean:         0 kB
Private_Dirty:       160 kB
Referenced:          388 kB
Anonymous:          5040 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
55def7fa4000-7fff73114000 ---p 00000000 00:00 0                          [rollup]
Rss:                5048 kB
Pss:                1221 kB
Pss_Anon:           1220 kB
Pss_File:              0 kB
Pss_Shmem:             1 kB
Shared_Clean:          4 kB
Shared_Dirty:       4884 kB
Private_Clean:         0 kB
Private_Dirty:       160 kB
Referenced:          388 kB
Anonymous:          5040 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
55def7fa4000-7fff73114000 ---p 00000000 00:00 0                          [rollup]
Rss:                6636 kB
Pss:                1718 kB
Pss_Anon:           1238 kB
Pss_File:            193 kB
Pss_Shmem:           286 kB
Shared_Clean:       1264 kB
Shared_Dirty:       4912 kB
Private_Clean:         0 kB
Private_Dirty:       460 kB
Referenced:         2056 kB
Anonymous:          5040 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB

=== syslog-ng ====

55d441476000-7ffe57cb3000 ---p 00000000 00:00 0                          [rollup]
Rss:               19084 kB
Pss:               16931 kB
Pss_Anon:          14646 kB
Pss_File:           2285 kB
Pss_Shmem:             0 kB
Shared_Clean:       2144 kB
Shared_Dirty:        356 kB
Private_Clean:      2116 kB
Private_Dirty:     14468 kB
Referenced:        17764 kB
Anonymous:         14824 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
---
55d441476000-7ffe57cb3000 ---p 00000000 00:00 0                          [rollup]
Rss:                 540 kB
Pss:                 362 kB
Pss_Anon:            362 kB
Pss_File:              0 kB
Pss_Shmem:             0 kB
Shared_Clean:          0 kB
Shared_Dirty:        356 kB
Private_Clean:         0 kB
Private_Dirty:       184 kB
Referenced:            4 kB
Anonymous:           540 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB