记录几个简单命令，具体参数后面慢慢分析吧
lion@ubuntu:~$ free
total used free shared buff/cache available
Mem: 4002268 1295684 1110936 12784 1595648 2428948
Swap: 969960 0 969960
lion@ubuntu:~$ top
top - 21:47:47 up 12 min, 2 users, load average: 1.27, 1.13, 0.67
Tasks: 339 total, 2 running, 253 sleeping, 0 stopped, 0 zombie
%Cpu(s): 6.7 us, 9.2 sy, 28.8 ni, 54.9 id, 0.2 wa, 0.0 hi, 0.3 si, 0.0 st
KiB Mem : 4002268 total, 1110044 free, 1296308 used, 1595916 buff/cache
KiB Swap: 969960 total, 969960 free, 0 used. 2428380 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2637 root 39 19 242264 131644 81888 R 94.4 3.3 7:30.83 unattended-upgr
3333 lion 20 0 51464 4088 3300 R 11.1 0.1 0:00.03 top
728 message+ 20 0 51692 6220 3980 S 5.6 0.2 0:01.17 dbus-daemon
1 root 20 0 160288 9560 6696 S 0.0 0.2 0:03.67 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.03 kthreadd
3 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_gp
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_par_gp
root@ubuntu:~# cat /proc/buddyinfo
Node 0, zone DMA 1 1 0 1 4 1 2 1 2 0 3
Node 0, zone DMA32 1344 772 489 454 338 218 60 64 33 5 14
Node 0, zone Normal 9 89 46 143 112 19 8 3 2 0 0
root@ubuntu:~# cat /proc/slabinfo
slabinfo - version: 2.1
# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
ext4_groupinfo_4k 168 168 144 56 2 : tunables 0 0 0 : slabdata 3 3 0
fsverity_info 0 0 248 66 4 : tunables 0 0 0 : slabdata 0 0 0
ip6-frags 0 0 184 44 2 : tunables 0 0 0 : slabdata 0 0 0
PINGv6 52 52 1216 26 8 : tunables 0 0 0 : slabdata 2 2 0
RAWv6 414 546 1216 26 8 : tunables 0 0 0 : slabdata 21 21 0
UDPv6 48 48 1344 24 8 : tunables 0 0 0 : slabdata 2 2 0
tw_sock_TCPv6 0 0 248 66 4 : tunables 0 0 0 : slabdata 0 0 0
request_sock_TCPv6 0 0 304 53 4 : tunables 0 0 0 : slabdata 0 0 0
TCPv6 26 26 2368 13 8 : tunables 0 0 0 : slabdata 2 2 0
kcopyd_job 0 0 3312 9 8 : tunables 0 0 0 : slabdata 0 0 0
dm_uevent 0 0 2632 12 8 : tunables 0 0 0 : slabdata 0 0 0