Counting number of syscalls

[geir]

Hello,
I have been trying to find an answer on google and in these forums, but maybe I am not using the correct search words. In any case, I cannot find it, but hopefully one of you experts will be able to answer.

1. I need to be able to count the number of system calls system wide per second, rather than for just one individual process (strace is good for the last one). This is on a 2.4 kernel.

2. Once a process has been started, how can you use strace or something else to get it to follow already existing children as well as the main process?

Thank you for your time.

-Geir