I've observed high memory usage at amazon ec2 instance using amazon Linux.
See attached image.
Top 25 processes shows < 1GB of memory, but free -m says ~ 3GB is consumed. I've already visited http://www.linuxatemyram.com/, but in my case cache is also displayed as consumed.
EDIT: I've low free count in -/+ buffers/cache in 2nd line of output.
Any idea?
Output from cat /proc/meminfo
MemTotal: 3857992 kB
MemFree: 85032 kB
MemAvailable: 3589668 kB
Buffers: 102704 kB
Cached: 176500 kB
SwapCached: 1876 kB
Active: 358416 kB
Inactive: 66924 kB
Active(anon): 159468 kB
Inactive(anon): 27128 kB
Active(file): 198948 kB
Inactive(file): 39796 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 8388604 kB
SwapFree: 8377616 kB
Dirty: 24 kB
Writeback: 0 kB
AnonPages: 144268 kB
Mapped: 45708 kB
Shmem: 40460 kB
Slab: 3308524 kB
SReclaimable: 3295052 kB
SUnreclaim: 13472 kB
KernelStack: 1744 kB
PageTables: 9056 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 10317600 kB
Committed_AS: 491944 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 11340 kB
VmallocChunk: 34359722271 kB
AnonHugePages: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 22528 kB
DirectMap2M: 3909632 kB