On Mon, Dec 12, 2011 at 02:47:57PM +0100, O. Hartmann wrote: > > > Not fully right, boinc defaults to run on idprio 31 so this isn't an > > issue. And yes, there are cases where SCHED_ULE shows much better > > performance then SCHED_4BSD. [...] > > Do we have any proof at hand for such cases where SCHED_ULE performs > much better than SCHED_4BSD? Whenever the subject comes up, it is > mentioned, that SCHED_ULE has better performance on boxes with a ncpu > > 2. But in the end I see here contradictionary statements. People > complain about poor performance (especially in scientific environments), > and other give contra not being the case. > > Within our department, we developed a highly scalable code for planetary > science purposes on imagery. It utilizes present GPUs via OpenCL if > present. Otherwise it grabs as many cores as it can. > By the end of this year I'll get a new desktop box based on Intels new > Sandy Bridge-E architecture with plenty of memory. If the colleague who > developed the code is willing performing some benchmarks on the same > hardware platform, we'll benchmark bot FreeBSD 9.0/10.0 and the most > recent Suse. For FreeBSD I intent also to look for performance with both > different schedulers available. > 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". -- SteveReceived on Mon Dec 12 2011 - 14:52:00 UTC
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