A couple things. First, it's best to avoid using `killall`. On Linux it searches the process list, but on Solaris and possibly other nixes, it kills all processes system-wide. Using `pkill` is a better habit, but read the manpage first because it matches a little differently.

Secondly, check out this extension for Chrome: https://chrome.google.com/webstore/detail/the-great-suspende... . It auto-suspends tabs that haven't been opened for a given time period (I think the default is 60 minutes). Can also whitelist domains, etc. I've been using it with great success for a long time now.