On Mon, Jan 24, 2011 at 8:07 PM, Chad Perrin <per...@apotheon.com> wrote:
> On Tue, Jan 25, 2011 at 01:02:46AM +0000, Craig Butler wrote: > > On Mon, 2011-01-24 at 16:57 -0700, Chad Perrin wrote: > > > I'm running a two-core laptop that, once in a great while, shows > > > approximately 250% CPU usage by a single process in top. How exactly > > > does that work? > > > > > > Note: It's not entirely surprising that this particular process is > > > consuming a lot of resources. It's just surprising to me that it's > > > consuming more than CPUs * 100%. > > > > Hi Chad > > > > Its to do with top using weighted CPU percentage... for some reason this > > show peaks as more usage than 100% -- maybe something to do with the top > > averaging out over a specific time. > > I find that raw CPU mode gives a more accurate representation. > > > > raw mode is toggled by passing the -C argument to top. > > Do you have a reference to a relatively simple explanation of how that > weighting works (and why)? > > -- > Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ] > man 1 ps: %cpu The CPU utilization of the process; this is a decaying average over up to a minute of previous (real) time. Since the time base over which this is computed varies (since processes may be very young) it is possible for the sum of all %cpu fields to exceed 100%. _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"