内存可用率

内存可用率

计算公式内存使用率=(1-free_rate)%100

公式说明:
free_rate=MEMFREE + BUFFERS + CACHED / MEMTOTAL

MEMFREE + BUFFERS + CACHED / MEMTOTAL 的值来自 /proc/meminfo

具体/proc/meminfo里有什么内容呢

[root@pod-hfwtibnuba ~]# cat /proc/meminfo 
MemTotal:        7912400 kB
MemFree:         1578976 kB
MemAvailable:    1912312 kB
Buffers:               0 kB
Cached:           786648 kB
SwapCached:            0 kB
Active:          5721620 kB
Inactive:         402760 kB
Active(anon):    5412012 kB
Inactive(anon):    15356 kB
Active(file):     309608 kB
Inactive(file):   387404 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:               572 kB
Writeback:             0 kB
AnonPages:       5336412 kB
Mapped:            89764 kB
Shmem:            125208 kB
Slab:             124536 kB
SReclaimable:      86860 kB
SUnreclaim:        37676 kB
KernelStack:       27456 kB
PageTables:        14612 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     3956200 kB
Committed_AS:    7933728 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
AnonHugePages:   4919296 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
DirectMap4k:       36732 kB
DirectMap2M:     4157440 kB
DirectMap1G:     6291456 kB

容器的内存使用率

计算公式
real_used = memory.usage_in_bytes - (rss + active_file + inactive_file)

memory.usage_in_bytes: /cgroup/memory/memory.usage_in_bytes 内容
rss + active_file + inactive_file 这些都来源于/cgroup/memory/memory.stat