missing opposite to mem_avail_percents

[nekopsykose]

the memory block has the following values:

//! `mem_free` | Free memory not yet used by the kernel or userspace (in general you should use mem_avail)
//! `mem_free_percents` | as above but as a percentage of total memory
//! `mem_avail` | Kernel estimate of usable free memory which includes cached memory and buffers
//! `mem_avail_percents` | as above but as a percentage of total memory
//! `mem_total_used` |  mem_total - mem_free
//! `mem_total_used_percents` | as above but as a percentage of total memory
//! `mem_used` | Memory used, excluding cached memory and buffers; same as htop's green bar
//! `mem_used_percents` | as above but as a percentage of total memory

mem_used is the used memory, but it excludes buffers. this green bar in htop does not include 'buffers/shared memory', which means it's not what free actually reports for used, which is the opposite of mem_avail.

for example the following:

free:

$ free
               total        used        free      shared  buff/cache   available
Mem:        32799040    22935160     1896944    12413232    20856892     9863880
Swap:       18874360     9843712     9030648

but in mem_used_percents, this is seen as 30%, even though it should be more like 65%+. this is because it presumably excludes shared memory from the calculation?

it would be nice if either it took that into account, or there was a new value that was just 1 - mem_avail_percents

if you want to test this yourself, you can easily force a large shared memory allocation by placing a huge file into tmpfs, e.g. fallocate -l 10G /tmp/bigfile. these usages are what is missing in mem_used even though they are actually used