Date: Tue, 13 Dec 2011 22:31:20 +0100 From: Malin Randstrom <malin.randstrom@gmail.com> To: Steve Kargl <sgk@troutmask.apl.washington.edu> Cc: freebsd-performance@freebsd.org, Current FreeBSD <freebsd-current@freebsd.org>, freebsd-stable@freebsd.org, "O. Hartmann" <ohartman@mail.zedat.fu-berlin.de> Subject: Re: SCHED_ULE should not be the default Message-ID: <CAHOgbn_Q5u1uYSZPcuCEx6KnbMYDPRL66qnmSiQgjhACzLJJ=Q@mail.gmail.com> In-Reply-To: <20111213155456.GA93017@troutmask.apl.washington.edu> References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <20111212155159.GB73597@troutmask.apl.washington.edu> <4EE751E2.60204@mail.zedat.fu-berlin.de> <20111213155456.GA93017@troutmask.apl.washington.edu>
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stop sending me spam mail ... you never stop despite me having unsubscribeb several times. stop this! On Dec 13, 2011 8:12 PM, "Steve Kargl" <sgk@troutmask.apl.washington.edu> wrote: > On Tue, Dec 13, 2011 at 02:23:46PM +0100, O. Hartmann wrote: > > On 12/12/11 16:51, Steve Kargl wrote: > > > 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. > > > > Well, those recommendations should based on "WHY". As the mostly > > negative experiences with SCHED_ULE in highly computative workloads get > > allways contradicted by "...but there are workloads that show the > > opposite ..." this should be shown by more recent benchmarks and > > explanations than legacy benchmarks from years ago. > > > > I have given the WHY in previous discussions of ULE, based > on what you call legacy benchmarks. I have not seen any > commit to sched_ule.c that would lead me to believe that > the performance issues with ULE and cpu-bound numerical > codes have been addressed. Repeating the benchmark would > be a waste of time. > > -- > Steve > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to " > freebsd-performance-unsubscribe@freebsd.org" >
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