I was using Ubuntu 19.10 and that was working perfectly, I decided to downgrade for some reasons to 18.04 LTS, It was also working fine in the starting but since a week before I am facing random lags while using Android Studio or IntelliJ Idea. Maybe I have installed any program which is causing this but I don't know. I have a very good system Corei9 12 cores with 16gb ram I also increased heap size but in vain. Currently, I am not in state to reinstall the OS. It lags randomly for 4,5 seconds while using Android Studio or IntelliJ Idea. The complete UI freezes during this, sound stops, cursor stops, etc... I don't have any graphics drivers issue as I am using built-in Intel HD graphics. Any method to diagnose this issue I don't know why is this happening.
total used free shared buff/cache available Mem: 15G 2.0G 7.2G 826M 6.4G 12G Swap: 0B 0B 0B
vm.swappiness = 60
grep -i swap /etc/fstab
/swapfile none swap sw 0 0