SCHED_ULE should not be the default
Bruce Cran
bruce at cran.org.uk
Mon Dec 12 16:18:39 UTC 2011
On 12/12/2011 15:51, Steve Kargl wrote:
> This comes up every 9 months or so, and must be approaching FAQ
> status. In a HPC environment, I recommend 4BSD. Depending on the
> workload, ULE can cause a severe increase in turn around time when
> doing already long computations. If you have an MPI application,
> simply launching greater than ncpu+1 jobs can show the problem. PS:
> search the list archives for "kargl and ULE".
This isn't something that can be fixed by tuning ULE? For example for
desktop applications kern.sched.preempt_thresh should be set to 224 from
its default. I'm wondering if the installer should ask people what the
typical use will be, and tune the scheduler appropriately.
--
Bruce Cran
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