2011/12/13 Jeremy Chadwick <freebsd_at_jdc.parodius.com>: > 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 is in no way shape or form the same kind of benchmark as what > you're planning to do, but I thought I'd throw it out there for folks to > take in as they see fit. > > I know folks were focused mainly on buildworld. > > I personally would find it interesting if someone with a higher-end > system (e.g. 2 physical CPUs, with 6 or 8 cores per CPU) was to do the > same test (changing -jX to -j{numofcores} of course). > > -- > | Jeremy Chadwick jdc at parodius.com | > | Parodius Networking http://www.parodius.com/ | > | UNIX Systems Administrator Mountain View, CA, US | > | Making life hard for others since 1977. PGP 4BD6C0CB | > > > sched_ule > =========== > - time make -j2 buildworld > 1689.831u 229.328s 18:46.20 170.4% 6566+2051k 432+4264io 4565pf+0w > - time make -j2 buildkernel > 640.542u 87.737s 9:01.38 134.5% 6490+1920k 134+5968io 0pf+0w > > > sched_4bsd > ============ > - time make -j2 buildworld > 1662.793u 206.908s 17:12.02 181.1% 6578+2054k 23750+4271io 6451pf+0w > - time make -j2 buildkernel > 638.717u 76.146s 8:34.90 138.8% 6530+1927k 6415+5903io 0pf+0w > > > software > ========== > * sched_ule test: FreeBSD 8.2-STABLE, Thu Dec 1 04:37:29 PST 2011 > * sched_4bsd test: FreeBSD 8.2-STABLE, Mon Dec 12 22:42:54 PST 2011 Hi Jeremy, thanks for the time you spent on this. However, I wanted to ask/let you note 3 things: 1) Did you use 2 different code base for the test? (one updated on December 1 and another one on December 12) 2) Please note that you should have repeated this test several times (basically until you don't get a standard deviation which is acceptable with ministat) and report the ministat output 3) The difference is less than 2% which I suspect is really statistically unuseful/the same I'm not really even surprised ULE is not faster than 4BSD in this case because usually buildworld/buildkernel tests are driven for the vast majority by I/O overhead rather than scheduler capacity. It would be more interesting to analyze how buildworld does while another type of workload is going on. Thanks, Attilio -- Peace can only be achieved by understanding - A. EinsteinReceived on Thu Dec 15 2011 - 15:26:30 UTC
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