I'm running a long duration CPU-centric process that will gobble up all available CPU time. I have it set to run at nice +20. While it's running I've noticed other processes have a hard time getting CPU time and run their activites very slowly. The processes I've noticed issues with are IO involved, but they don't appear to be IO blocked as they run dramatically faster and use much more CPU time when the CPU intensive process is not running. I haven't noticed issues with other processes, but I haven't been looking. If I push my CPU intensive process into idle priority 1, all the other processes return to their normal behaviour as if it's not running. This seems to be a specific behaviour on this one machine running 9.0-RELEASE-p4 on an Atom 330 dual core. I've tried with and without hyperthreading enabled with no noticeable change in behaviour.
On 10/29/2012 08:33 PM, Steven Nikkel wrote:> I'm running a long duration CPU-centric process that will gobble up all > available CPU time. I have it set to run at nice +20. While it's running > I've noticed other processes have a hard time getting CPU time and run > their activites very slowly. The processes I've noticed issues with are > IO involved, but they don't appear to be IO blocked as they run > dramatically faster and use much more CPU time when the CPU intensive > process is not running. I haven't noticed issues with other processes, > but I haven't been looking. If I push my CPU intensive process into idle > priority 1, all the other processes return to their normal behaviour as > if it's not running. > > This seems to be a specific behaviour on this one machine running > 9.0-RELEASE-p4 on an Atom 330 dual core. I've tried with and without > hyperthreading enabled with no noticeable change in behaviour. > > _______________________________________________ > freebsd-stable at freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"I will likely irritate some people, but you could try the 4BSD scheduler, see if that gives you better results.
on 30/10/2012 03:33 Steven Nikkel said the following:> I'm running a long duration CPU-centric process that will gobble up all > available CPU time. I have it set to run at nice +20. While it's running I've > noticed other processes have a hard time getting CPU time and run their > activites very slowly. The processes I've noticed issues with are IO involved, > but they don't appear to be IO blocked as they run dramatically faster and use > much more CPU time when the CPU intensive process is not running. I haven't > noticed issues with other processes, but I haven't been looking. If I push my > CPU intensive process into idle priority 1, all the other processes return to > their normal behaviour as if it's not running. > > This seems to be a specific behaviour on this one machine running 9.0-RELEASE-p4 > on an Atom 330 dual core. I've tried with and without hyperthreading enabled > with no noticeable change in behaviour.Can you try with lower nice value, like +10? You want a fix from r228718. AFAIR, it is not in 9.0. -- Andriy Gapon