add experimental support for psd on unionfs

[nefelim4ag]

I create this for fix slowdown startup on big profiles. All changed function separated by option check (if non zero). When psd start he check if "unionfs" exist. if no, he set EXP_UNIONFS="" and psd work in default mode. By default option commented in psd.conf

[graysky2]

Seems interesting. I don't use unionfs so I cannot test... not sure how I feel about merging into the stable branch without testing.

[nefelim4ag]

This is safety for merging, because new features shielded by this function [[ ! -z $EXP_UNIONFS ]] && command -v unionfs >/dev/null 2>&1 || { EXP_UNIONFS=""; echo "I require unionfs-fuse but it's not installed. Work in default mode." >&2; } I test and debug this approximately second day and now this fun. Now i try test acceleration by unionfs. (also add 2 commit to manage psd.conf if he changed while psd running)

[nefelim4ag]

Tests 1.1G /home/timofey/.config/chromium Unionfs enabled sudo systemctl start psd 0.01s user 0.00s system 0% cpu 1.567 total sudo systemctl stop psd 0.01s user 0.00s system 0% cpu 1.610 total Unionfs disabled sudo systemctl start psd 0.01s user 0.00s system 0% cpu 13.067 total sudo systemctl stop psd 0.00s user 0.01s system 0% cpu 1.588 total

I using unionfs because he has fuse module. unionfs-fuse no needed for working psd. But if somebody want enable new feature, he need install unionfs-fuse or psd just continue working in common case.

[nefelim4ag]

Delete this, i rework my solution and send nice patch set after additional testing.

[graysky2]

Actually, when you update your code, the pull request updates with it I believe.

[graysky2]

OK. Closing per your request.