Default [Q] swap help

hi there. I have a Alcatel OT Idol Mini with 512 mb RAM. my device is rooted.
I installed Swap for root and it works.. Also I tested by typing "free" on terminal emulator and it shows that swap is working.
But if I had 3 or more app opened in background, when I want to open them again, the apps are restarting.. although I have enough swap memory free.
Is it normal or is a problem with swap app? how can I prevent the apps from closing when in background?

p.s. sorry for my english.