i use Ubuntu classic - gnome2 - i have the system monitor on the panel with memory, network and cpu indicators.
Using Qbittorrent the cache RAM increases slowing the system
Then I execute
# sudo su
# sync; echo 3 > /proc/sys/vm/drop_caches
And I do clear the cache...
If Qbittorrent would clear the cache at certain conditions - configurable - with a default config, for example of 30% of total RAM it will not freeze Linux systems.
PS this script does not work for me, but in theory it must.
#!/bin/bash
clear
sync
su -c "echo 3 > /proc/sys/vm/drop_caches"
exit