Using large amounts of system time

Ian Lynagh igloo@earth.li
Mon, 10 Feb 2003 17:02:30 +0000


Hi all,

I appear to be using huge amounts of CPU time, and I am trying to work
out why. The commands I ran and their output are in systime_log at
http://urchin.earth.li/~ian/systime/, and all the source and other
output is there too. Essentially the program uses more system time than
user time according to time (bash built-in, Linux x86), and I'd like to
know why (or more precisely I'd like to reduce it, but knowing why seems
like a good first move  :-)  ).

I'm somewhat confused as to why the numbers given by time and strace -c
don't match, but nevertheless it looks to me like the time must be due
to one or more of:

rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [], [], 8)    = 0
--- SIGVTALRM (Virtual timer expired) ---
sigreturn()                             = ? (mask now [])

I'm not sure where to go from here. Any suggestions?


Thanks
Ian