On 15 August 2017 at 07:41, Robbert Eggermont <[email protected]> wrote:
> > On 14-08-17 07:50, Lachlan Musicman wrote: > >> We have TaskPlugin=task/cgroup and when testing I noticed that the # of >> threads/cpus being allocated was rounded up to the nearest even. I presume >> this was due to cgroups marking a core as a cpu, rather than a thread as a >> cpu. >> > > Sounds like you're using SelectTypeParameters=CR_Core[_Memory], where > what you want requires SelectTypeParameters=CR_CPU[_Memory]? > No, we are using SelectTypeParameters=CR_CPU_Memory > I was hoping that the cgroup would kill the job because of too many cpus >> > > task/cgroup just limits the CPUs available to a job; a job can still have > any number of threads. (The number of *running* threads is of course > limited to the number of available CPUs.) > Ok, this is fine. I think I realised this late - as I read the stress-ng man page and saw that the threads would just wait for the others to finish. Is it possible to have granular control at the thread level with cgroups? >> > > Not that I know. Limiting the maximum number of threads can be done via > resource limits. > Interestingly, sinfo is also rounding up sinfo -Nle -o "%.20n %.15C %.8O %.7t" | uniq Tue Aug 15 11:05:59 2017 HOSTNAMES CPUS(A/I/O/T) CPU_LOAD STATE compute34 4/4/0/8 6.42 mix compute35 4/4/0/8 6.45 mix Cheers L. ------ "The antidote to apocalypticism is *apocalyptic civics*. Apocalyptic civics is the insistence that we cannot ignore the truth, nor should we panic about it. It is a shared consciousness that our institutions have failed and our ecosystem is collapsing, yet we are still here — and we are creative agents who can shape our destinies. Apocalyptic civics is the conviction that the only way out is through, and the only way through is together. " *Greg Bloom* @greggish https://twitter.com/greggish/status/873177525903609857
