wait, out of curiosity; "Sockets=2 CoresPerSocket=10 ThreadsPerCore=2 CPUs are set to 40 and SelectTypeParameters=CR_CPU"
this is actually allowing you to run 40 processes? When I tried it, it showed 40 available cpus, but would only allocate at the core level, not thread level, and hence was a hard limit of 20. On Wed, Sep 21, 2016 at 9:54 PM, Lachlan Musicman <[email protected]> wrote: > On a side note, I have a minor documentation bug report: > > On this page http://slurm.schedmd.com/cpu_management.html there is a link to > > -s, --oversubscribe > > which points to > > http://slurm.schedmd.com/srun.html#OPT_share > > The actual link is > > http://slurm.schedmd.com/srun.html#OPT_oversubscribe > > cheers > L. > > > ------ > The most dangerous phrase in the language is, "We've always done it this > way." > > - Grace Hopper > > On 22 September 2016 at 14:51, Lachlan Musicman <[email protected]> wrote: >> >> Our nodes have >> >> Sockets=2 CoresPerSocket=10 ThreadsPerCore=2 >> >> CPUs are set to 40 and SelectTypeParameters=CR_CPU >> >> According to this FAQ, this is "not a typical configuration". >> >> http://slurm.schedmd.com/faq.html#cpu_count >> >> Which is fine, I am aware that this is the set up - I did the >> configuration. >> >> One of our users is complaining that we don't have the regular set up with >> a "cpu=core" rather than a "cpu=thread". >> >> In reality, a large majority of our users run non thread aware >> bioinformatics software, so I am ok with our current set up - most of our >> jobs are largely parallel. >> >> Since changing to cpu=core setup would halve our resources, unless I could >> convince or remind people to use srun --shared (according to >> http://slurm.schedmd.com/cons_res_share.html ) >> >> Alternatively OverSubscribe=FORCE would solve that problem of lazy/greedy >> users, but doesn't that then override any advantage a hyperthreaded software >> might have? >> >> What are the nuances between the set up we have, and using OverSubscribe=X >> with cpu=core (given that core=2 threads)? >> >> Would there be a performance benefit from making cpu=core and halving the >> available processes - would the halved number of processes run/finish faster >> making up for the loss of flexibility? >> >> Cheers >> L. >> >> >> ------ >> The most dangerous phrase in the language is, "We've always done it this >> way." >> >> - Grace Hopper > >
