Как считается available memory в утулите top в ubuntu 16.04?

Question

[Пума Тайланд]

Вывод топа вот такой
top - 11:52:26 up 2 days, 17:32, 1 user, load average: 0.06, 0.07, 0.02
Tasks: 179 total, 1 running, 178 sleeping, 0 stopped, 0 zombie
%Cpu(s): 4.2 us, 0.3 sy, 0.0 ni, 95.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 4045040 total, 2911620 free, 148104 used, 985316 buff/cache
KiB Swap: 4194300 total, 3604936 free, 589364 used. 3768512 avail Mem

avail Mem не равен free memory, как он считается?

Answer 1

[ipc_ngs]

$ man top

The avail number on line 2 is an estimation of physical memory available for starting new applications, without swapping. Unlike the free field, it attempts to account for readily reclaimable page cache and memory slabs. It is available on kernels 3.14, emulated on kernels 2.6.27+, otherwise the same as free.