SCHED_ULE should not be the default

Ivan Klymenko fidaj at ukr.net
Mon Dec 12 16:28:45 UTC 2011


В Mon, 12 Dec 2011 16:18:35 +0000
Bruce Cran <bruce at cran.org.uk> пишет:

> 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.
> 

This is by and large does not help in certain situations ...


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