I've noticed that postgres strace output contains long groups of
setitimer/semop/setitimer.
Just FYI: semtimedop is a special syscalls that implements a semop with
a timeout. It was added just for the purpose of avoiding the setitimer
calls.
I know that it's supported by Solaris and recent Linux versions, I'm not
sure about other operating systems.
Has anyone tried to use it? Oracle pushed it to Linux, it seems to be
worth the effort:
http://www.ussg.iu.edu/hypermail/linux/kernel/0211.3/0485.html
-- Manfred