$free -th
total used free shared buff/cache available
Mem: 31G 1.5G 28G 79M 1.1G 29G
Swap: 2.0G 0B 2.0G
Total: 33G 1.5G 30G
...
KiB Mem : 32832784 total, 30064040 free, 1579628 used, 1189116 buff/cache
KiB Swap: 2097148 total, 2097148 free, 0 used. 30760488 avail Mem
...
1189116 buff/cache
buff and cache column -> buffer cache
vmstat -w 1
procs -----------------------memory---------------------- ---swap-- -----io---- -system-- --------cpu--------
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 0 30052984 119008 1078384 0 0 66 6 792 1632 2 1 98 0 0
0 0 0 30052724 119008 1078388 0 0 0 0 7244 14004 0 1 99 0 0
0 0 0 30055024 119008 1076084 0 0 0 0 10043 19655 0 1 99 0 0
slabtop displays detailed kernel slab cache information in real time.
It displays a listing of the top caches sorted by one of the listed sort criteria.
It also displays a statistics header filled with slab layer information.
sudo slabtop -o
Active / Total Objects (% used) : 881272 / 898900 (98.0%)
Active / Total Slabs (% used) : 24976 / 24976 (100.0%)
Active / Total Caches (% used) : 102 / 151 (67.5%)
Active / Total Size (% used) : 224446.49K / 230393.23K (97.4%)
Minimum / Average / Maximum Object : 0.01K / 0.26K / 16.81K
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
...
88620 82099 0% 0.19K 4220 21 16880K dentry
31185 30925 0% 0.58K 1155 27 18480K inode_cache
21330 19517 0% 1.05K 711 30 22752K ext4_inode_cache
17184 16972 0% 0.65K 716 24 11456K proc_inode_cache
...