[slurm-users] How to set priorities of actual obs

[Renfro, Michael]

A 'nice -n 19' process will still consume 100% of the CPU if nothing else is going on.

‘top’ output from a dual-core system with 3 ‘dd’ processes -- 2 with default nice value of 0, and 1 with a nice value of 19:

=====

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
15743 renfro    20   0  107992    612    512 R  99.3  0.0   0:54.60 dd
15705 renfro    20   0  107992    608    512 R  98.3  0.0   1:19.81 dd
15671 renfro    39  19  107992    612    512 R   1.7  0.0   1:44.70 dd

=====

After killing one of the default priority processes, the nice value 19 process can still take up a full core:

=====

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
15671 renfro    39  19  107992    612    512 R  99.3  0.0   1:54.43 dd
15743 renfro    20   0  107992    612    512 R  99.3  0.0   1:12.58 dd

=====

So your slurm-generated processes should be running at full speed if nothing else is going on.

> On Sep 14, 2018, at 9:09 AM, kesim <ketiwsim at gmail.com> wrote:
> 
> Dear Dimitri,
> 
> Thank you for the answer. I was considering this but I would have to relay on users to submit their jobs that way. I just found a simpler solution but also somewhat limited in scope:
> If 
> PropagatePrioProcess is set to 0  which is a default then the tasks will inherit slurmd priority. 
> You can set it by:  slurmd -n 19
> 
> However it would be nicer if the partitions itself can be separately managed - for short jobs with higher priority etc.
> 
> Best regards,
> 
> Ketiw  
> 
> On Fri, Sep 14, 2018 at 3:37 PM Dmitri Chebotarov <dchebota at gmu.edu> wrote:
> Hi Ketiw, 
> 
> Wouldn't 'nice' work in this case?
> 
> $ man nice
> ...
> NAME
>        nice - run a program with modified scheduling priority
> 
> SYNOPSIS
>        nice [OPTION] [COMMAND [ARG]...]
> ...
> 
> In your submit script you would run the program as
> 
> nice -n 19 <program-name>
> 
> 
> 
> -----Original Message-----
> From: slurm-users <slurm-users-bounces at lists.schedmd.com> On Behalf Of Loris Bennett
> Sent: Friday, September 14, 2018 9:15 AM
> To: slurm-users at lists.schedmd.com
> Subject: Re: [slurm-users] How to set priorities of actual obs
> 
> 
> kesim <ketiwsim at gmail.com> writes:
> 
> >> On Fri, Sep 14, 2018 at 2:41 PM Loris Bennett <loris.bennett at fu-berlin.de> wrote:
> >>
> >>  Hi Ketiw,
> >>
> >>  kesim <ketiwsim at gmail.com> writes:
> >>
> >>  > Dear all,
> >>  >
> >>  > I would like to submit a job in such a way that the actual program 
> >> is  > run with the lowest priority (nice=19 on linux). At the moment 
> >> every  > task has priority 0. Is it possible to do that and how?
> >>  >
> >>  > Best regards,
> >>  >
> >>  > Ketiw
> >>
> >>  I'm not aware that this is possible. What would be the use-case for  
> >> this? Normally you would want a job to make full use of any cores it  
> >> had reserved.
> 
> > I have slurm running on several desktops and we have only a few 
> > application for its use. I would like the slurm submitted tasks to 
> > have lowest priority so they are not hampering users who normally work 
> > on their desktops.
> 
> Please write to the list, rather than to me directly.
> 
> I think you can probably achieve what you want with cgroups, but I have no experience of doing this myself.
> 
> Regards
> 
> Loris
> 
> --
> Dr. Loris Bennett (Mr.)
> ZEDAT, Freie Universität Berlin         Email loris.bennett at fu-berlin.de
>