I have some thoughts about initial sort. It looks like insertion sort is not especially good if the list is not pre-sorted. For that case it looks like merge sort should work much better.
Regagrds Anton 2016-09-16 17:43 GMT+02:00 Bruno Chareyre <[email protected]>: > Pardon my 2nd email, it is irrelevant. > Back to the o.p.: I just checked https://yade-dem.org/wiki/Performance_Test > And the results are somehow similar, large times are allotted to force > resetter in parallel executions of "yade --performance". > So it is not a recent regression. > > Something noticeable in Alexander's timing is that the rel time of the > resetter decreases when the number of time iterations is decreased. > It seems there is a constant cost at play in the first iteration. The cost > seem to approach 10% for longer simulations, that's ok maybe. > Cheers > Bruno > > > On 09/16/2016 09:42 AM, Eulitz, Alexander wrote: > > Hi Bruno, > > do you think that the problem exists for a while or when did openMP issues > arise? > > regards > > Alex > > > > Von: Yade-dev > [mailto:yade-dev-bounces+alexander.eulitz=iwf.tu-berlin...@lists.launchpad.net] > Im Auftrag von Bruno Chareyre > Gesendet: Freitag, 16. September 2016 00:19 > Cc: Yade developers > Betreff: Re: [Yade-dev] Regression in ForceResetter? > > > > Wait... > > Now I realize that the timings are weird. Real times are the same, relative > times are different. > > It could be that the counting is wrong. Something system/hardware dependent. > > We have troubles with openMP at the moment. So forget it. > > Thanks for the link anyway Anton. > > B > > > > On 15 September 2016 at 19:42, Anton Gladky <[email protected]> wrote: > > Hi Bruno, > > the only more-less relevant commit is the following [1]. Try to comment > that line and check, whether the regression is no more visible. If it > is so, that problem (described in commit log) should be solved by > more elegant way. > > [1] > https://github.com/yade/trunk/commit/07940b52ac31597c07d9d98f2891311d7e6d8e0e > > Cheers > > Anton > > > > 2016-09-15 19:23 GMT+02:00 Bruno Chareyre <[email protected]>: >> Hello all, >> >> I just noticed something I don't think I've ever seen before. >> I'm wondering if some recent changes in force containers (I've seen some >> by >> Anton IIRC) could explain that. >> Below are the outputs of "yade --performance" and "yade -j6 --performance" >> (same build). >> With -j1 the force resetter takes 3.55% of the total cpu time, not >> negligible but ok, we can live with that. >> With -j6 the absolute time it takes is multiplied by 3 almost, reaching >> 21% >> in terms of rel. time. This is huge and seriously degradate the >> performance >> of the parallel run. >> >> Could someone confirm this? >> >> Bruno >> ______________________ >> 1 CORE >> >> number of bodies 47323 >> >> Elapsed 66.9550299644 sec >> Performance 20.9095567688 iter/sec >> Extrapolation on 1e5 iters 1.32847281675 hours >> =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=* >> Name Count Time Rel. time >> >> ------------------------------------------------------------------------------------------------------- >> ForceResetter 1400 2373474us >> 3.55% >> InsertionSortCollider 39 4636343us >> 6.93% >> InteractionLoop 1400 49261433us >> 73.62% >> NewtonIntegrator 1400 10642155us >> 15.90% >> TOTAL 66913407us 100.00% >> _______________________ >> 6 CORES >> >> number of bodies 47323 >> >> Elapsed 29.4499371052 sec >> Performance 47.5383018646 iter/sec >> Extrapolation on 1e5 iters 0.584324148912 hours >> =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=* >> Name Count Time Rel. time >> >> ------------------------------------------------------------------------------------------------------- >> ForceResetter 1400 6370788us >> 21.66% >> InsertionSortCollider 39 1957601us >> 6.66% >> InteractionLoop 1400 13912593us >> 47.30% >> NewtonIntegrator 1400 7174500us >> 24.39% >> TOTAL 29415483us 100.00% >> >> -- >> _______________ >> Bruno Chareyre >> Associate Professor >> ENSE³ - Grenoble INP >> Lab. 3SR >> BP 53 >> 38041 Grenoble cedex 9 >> Tél : +33 4 56 52 86 21 >> Fax : +33 4 76 82 70 43 >> ________________ >> >> Email too brief? >> Here's why! http://emailcharter.org >> >> >> > >> _______________________________________________ >> Mailing list: https://launchpad.net/~yade-dev >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~yade-dev >> More help : https://help.launchpad.net/ListHelp > > _______________________________________________ > Mailing list: https://launchpad.net/~yade-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~yade-dev > More help : https://help.launchpad.net/ListHelp > > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~yade-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~yade-dev > More help : https://help.launchpad.net/ListHelp > > > > _______________________________________________ > Mailing list: https://launchpad.net/~yade-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~yade-dev > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~yade-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
