What contributes to memory "usage" in the OOM killer output in kernel 5.4

This is one of recent OOMs I’ve captured

Nov  3 03:00:24 node kernel: [  457.525768] memory: usage 98304kB, limit 98304kB, failcnt 0
Nov  3 03:00:24 node kernel: [  457.525769] memory+swap: usage 98304kB, limit 98304kB, failcnt 55087
Nov  3 03:00:24 node kernel: [  457.525770] kmem: usage 7124kB, limit 9007199254740988kB, failcnt 0
Nov  3 03:00:24 node kernel: [  457.525770] Memory cgroup stats for ...
Nov  3 03:00:24 node kernel: [  457.525781] anon 22626304
Nov  3 03:00:24 node kernel: [  457.525781] file 70610944
Nov  3 03:00:24 node kernel: [  457.525781] kernel_stack 110592
Nov  3 03:00:24 node kernel: [  457.525781] slab 6397952
Nov  3 03:00:24 node kernel: [  457.525781] sock 0
Nov  3 03:00:24 node kernel: [  457.525781] shmem 0
Nov  3 03:00:24 node kernel: [  457.525781] file_mapped 270336
Nov  3 03:00:24 node kernel: [  457.525781] file_dirty 70152192
Nov  3 03:00:24 node kernel: [  457.525781] file_writeback 0
Nov  3 03:00:24 node kernel: [  457.525781] anon_thp 0
Nov  3 03:00:24 node kernel: [  457.525781] inactive_anon 0
Nov  3 03:00:24 node kernel: [  457.525781] active_anon 22573056
Nov  3 03:00:24 node kernel: [  457.525781] inactive_file 35299328
Nov  3 03:00:24 node kernel: [  457.525781] active_file 35532800
Nov  3 03:00:24 node kernel: [  457.525781] unevictable 0
Nov  3 03:00:24 node kernel: [  457.525781] slab_reclaimable 4997120
Nov  3 03:00:24 node kernel: [  457.525781] slab_unreclaimable 1400832
Nov  3 03:00:24 node kernel: [  457.525781] pgfault 12144
Nov  3 03:00:24 node kernel: [  457.525781] pgmajfault 165
Nov  3 03:00:24 node kernel: [  457.525781] workingset_refault 67584
Nov  3 03:00:24 node kernel: [  457.525781] workingset_activate 1683
Nov  3 03:00:24 node kernel: [  457.525781] workingset_nodereclaim 0
Nov  3 03:00:24 node kernel: [  457.525781] pgrefill 1065240
Nov  3 03:00:24 node kernel: [  457.525781] pgscan 1251644
Nov  3 03:00:24 node kernel: [  457.525781] pgsteal 164761
Nov  3 03:00:24 node kernel: [  457.525781] pgactivate 1082994
Nov  3 03:00:24 node kernel: [  457.525781] pgdeactivate 1063879
Nov  3 03:00:24 node kernel: [  457.525781] pglazyfree 0
Nov  3 03:00:24 node kernel: [  457.525782] Tasks state (memory values in pages):

memory: usage 98304kB, limit 98304kB — from my limited understanding the usage here consists of:

1. anon
2. file_dirty
3. file_mapped (not so sure about this one actually)

How wrong is my assumption? What else contributes to the final memory usage number or may be I have picked wrong ones initially?

(it’s for 5.4.0-1029-aws #30~18.04.1-Ubuntu)