On 02/08/2016 12:57 PM, Khalid Mughal (khalidm) wrote:

How do we explain the discrepancy between MemAvaiable and MemFree count
after we drop cache? In following output, which one represents correct
data?

[Linux_0:/]$ cat /proc/meminfo
MemTotal:        3977836 kB
MemFree:          747832 kB
MemAvailable:    1441736 kB
Buffers:          123976 kB
Cached:          1210272 kB
Active:          2496932 kB
Inactive:         585364 kB
Active(anon):    2243932 kB
Inactive(anon):   142676 kB
Active(file):     253000 kB
Inactive(file):   442688 kB
Dirty:                44 kB
AnonPages:       1748088 kB
Mapped:           406512 kB
Shmem:            638564 kB
Slab:              65656 kB
SReclaimable:      30120 kB
SUnreclaim:        35536 kB
KernelStack:        5920 kB
PageTables:        19040 kB
CommitLimit:     1988916 kB
Committed_AS:    3765252 kB

[Linux_0:/]$ echo 3 > /proc/sys/vm/drop_caches
[Linux_0:/]$ cat /proc/meminfo
MemTotal:        3977836 kB
MemFree:         1095012 kB
MemAvailable:    1434148 kB

I suspect MemAvailable takes into account more than just the droppable 
caches. For instance, reclaimable slab is included, but I don't think 
drop_caches drops that part.

Daniel

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