What does CheckingMemUsageSize option do?

[ReallyCoolName]

Does anyone know what does this option, which was introduced in version 4.1.5 do in qbittorrent-4.1.5/src/base/bittorrent/session.cpp file:
m_checkingMemUsage(BITTORRENT_SESSION_KEY("CheckingMemUsageSize"), 16)

FEATURE: Add checking_mem_usage option to AdvancedSettings (FranciscoPombal)

If I use  DiskCacheSize 1024MB and not default 64MB, should I also increse this CheckingMemUsageSize ? If yes - to what value should I change it?

p.s. Just found this explanation in https://www.libtorrent.org/include/libt ... ttings.hpp

// the number of blocks to keep outstanding at any given time when
// checking torrents. Higher numbers give faster re-checks but uses
// more memory. Specified in number of 16 kiB blocks
int checking_mem_usage;

^ Still not sure what setting I should use for 1024MB cache size on 2GB RAM machine.