[cfarm-users] peko, please 'nice' your jobs

[Jonathan Wakely]

On 26 March 2018 at 15:19, Stefan Ring <stefan at complang.tuwien.ac.at> wrote:
> On Mon, Mar 26, 2018 at 3:56 PM, Jonathan Wakely via cfarm-users
> <cfarm-users at lists.tetaneutral.net> wrote:
>> I can't remember ever using gcc112 when it wasn't running several jobs
>> for "peko", all run without nice.
>>
>> Please remember these are shared machines, and running jobs
>> back-to-back all day, every day doesn't seem necessary.
>
> Unfortunately, nice buys you close to nothing on machines with
> multiple virtual threads per core (Hyper Threading or SMT), and the

Yeah I wasn't sure if that was the case, but I think we do have a
policy that automated jobs on the farm should be niced.

> POWER machines are heavily multi-threaded. So the only good remedy is
> to start fewer simultaneous jobs than there are physical cores in a
> machine.

Peter's jobs rarely use a huge number of cores (and gcc112 has a lot
of them) so my request was as much that he doesn't just run constant
jobs in a permanent loop, which the machines are not meant to be for.

This applies to others too of course.