七年级英语下册 The Fastest POP in the World 课件.ppt

thefastestpopintheworld,thecrayx1premierweather/climateworkhorse,understandingthex1weather/climateapplicationsoptimizedforx1nlom,pop,hycom,romweather/climateapplicationsbeingoptimizedforthex1ccsm,mm5,wrf,hirlam,ifs,.someresults,understandingthex1,mustbewillingtorestructurethecompilerwillneverbegoodenoughtodoitallscalarisverybadshortvectorisgood,butyoucandobetterdonotbesatisfiedwithvectorizationofthedepth/heigthloopthex1inter-connectallowsforscalingtoveryhighsustaingflops,popoptimizations,impvmixtandimpvmixupullingtheinnerloopinsidethekloopcsddirectivesontheseconddimensionkloopisinthemiddleaniso_hmixpullingtheinnerloopinsidethequadrantloop(4)pullingtheinnerloopinsidecasestatementscsddirectivesontheseconddimension,co-arrays,onlyusedwherempineededhelpglobal_summationnine-pointstencilinsolveriterationloopstartedusinglocksinsteadofbarriersusedataskewingwiththelocksandglobalsummationscalar,howtowriteaglobal_sumusingco-arrays,allprocessorscomeintotheroutine.everyonedoeslocalsumand/orstoreslocalscalarintoco-arrayscalartellsmaster(processor1(or0)thatithassetvaluespinsonmasterreadyflagmasterreadsallscalars,performssumbroadcastsscalartoallprocessorsbroadcastsmaster_readyflagtoallprocessors,whatthechildrendo,!sumlocalcontributionsreduce_real_local=c0doj=jphys_b,jphys_edoi=iphys_b,iphys_ereduce_real_local=reduce_real_local+x(i,j)*mask(i,j)enddoenddo!sendlocalsumtomasterreduce_real_global(1,me)1=reduce_real_localcallsync_memory()child_ready(1,me)1=.true.if(me.eq.1)thenthisisthemastercodeelsedowhile(.not.master_ready(1,me)enddomaster_ready(1,me)=.false.endifglobal_sum_caf=reduce_real_global(,me)endfunctionglobal_sum_caf,whatthemasterdoes,if(me.eq.1)then!waituntilalllocalresultshavearrivedchildren_ready=.false.dowhile(.not.children_ready)children_ready=.true.doi=2,nproc_x*nproc_ychildren_ready=children_ready.and.child_ready(1,i)enddoenddodoi=2,nproc_x*nproc_ychild_ready(1,i)=.false.enddo!globalsumglobal_sum=reduce_real_global(1)doi=2,nproc_x*nproc_yglobal_sum=global_sum+reduce_real_global(1,i)enddo,whatthemasterdoes,!broadcastdoi=1,nproc_x*nproc_yreduce_real_global(1,i)i=global_sumenddocallsync_memory()doi=2,nproc_x*nproc_ymaster_ready(1,i)i=.true.enddo,makesurethatchild_readyandmaster_readyaretypedvolatile.,popresultsfullmodel,crayx1performsandscaleswelloverallco-arrayfortranscalesmuchbetterthanmpi,popresultsbaroclinic,baroclinicportionofpopscaleswellforallsystems,particularlycrayx1co-arrayfortranandmpihavesimilarperformance,popresultsbarotropic,barotropicportionofpopgenerallydoesnotscalewellcrayx1co-arrayfortranperformanceisexcellentcrayx1mpiperformancenotasgood,nlom,oceanmodelusedatnavoceanalreadywritteninshmemandco-arrayusedtheshmemversionofthecodefew,minoroptimizationsmergingofmultiplelapackroutines,nlom,hycom,vectorizationandparallelizationonlat/lonloopssignificantimprovementoveroptimizationoninnerkloopsnotmyworknathanwichmannofcray,mm5,mesoscalemodeltheillustratetimingsareusingmpi,evenbetterscalingwillbeachievedwithco-arraysnotmywork.tonyhey(ahpscc),frankkampe,petejohnsonofcrayon-goingworkwithmikerezneyofcray,whatisaprocessoronthex1?,mspsmulti-streamingprocessor4onanode,verylowsynctimecompilerwillautomaticallygeneratemspcodesplitoneloopover4sspsparallelizeouterloopoverssps,vectorizeonsspsspssingle-streamingprocessor2pipevectorprocessorcostofmsp=costof4ssps,12.8gflops(64bit),25.6gflops(32bit),tolocalmemoryandnetwork:,2mbecache,atfrequencyof400/800mhz,25-41gb/s,25.6gb/s,12.8-20.5gb/s,customblocks,crayx1multi-streamingprocessor,romuni-processorsresults,regionaloceanmodelfromalaskaregionalsupercomputingcenter(arsc)workinconjunctionwithkatehedstromofarscireworkedbulk_fluxroutine,katedebuggeditandthetimewentfrom2510secondsonthex1to1652secondswithcompileroptions.timeonpower4systemswas1020secondsrestructuringtooktimedownto171seconds,ccsm,communitycoupledmodelpopalreadytalkedaboutlandmodeloptimizedbyornlcicehighlyvectorizedbylanl/fujitsucamcraycurrentlyworkingtoimprovesingleprocessorperformanceandscalingcrayisnowtestingmultiplebinarylaunchformpi,cam,co-arraysusedinmpi-wrapperroutineongoingworkco-arraysbeingusedinthereallocroutinesvectorizationofcloudphysics,wrf,highlyvectorizableneedtoplaywithoptionstoachievethebestperformanceonthex1ahpsccan