After looking for so many answers on StackOverflow, I haven't seen an answer to fit my needs.
That is, to make top command to keep refreshing with given keyword, and we don't have to CTRL+C / top again and again when new processes spawn.
Thus I make a new one...
Here goes the no-restart-needed version.
__keyword=name_of_process; (while :; do __arg=$(pgrep -d',' -f $__keyword); if [ -z "$__arg" ]; then top -u 65536 -n 1; else top -c -n 1 -p $__arg; fi; sleep 1; done;)
Modify the __keyword and it should works. (Ubuntu 2.6.38 tested)
2.14.2015 added:
The system workload part is missing with the code above.
For people who cares about the "load average" part:
__keyword=name_of_process; (while :; do __arg=$(pgrep -d',' -f $__keyword); if [ -z "$__arg" ]; then top -u 65536 -n 1; else top -c -n 1 -p $__arg; fi; uptime; sleep 1; done;)