Re: [HTCondor-users] CPU usage

[Brian Candler <b.candler@xxxxxxxxx>]

On 24/06/2015 14:54, Ben Cotton wrote:
> So do you want the full machine to be available during the day if the
> machine isn't being used, or do you always want some number of slots
> reserved during working hours?
I'm not convinced that limiting the number of slots will make a 
difference, if the jobs themselves are multi-threaded - in that case, 
won't they just use as many cores as are available?

That's unless you there are cgroup restrictions. Even then I don't think 
it will work unless Condor configures CPU bandwidth control:

https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt
https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt

BWC throttles processes in 100ms windows if they try to use more than 
their allotted timeshare. There is a nice picture here:
http://aurora.apache.org/documentation/latest/resource-isolation/#cpu-isolation

Regards,

Brian.