Energy'Introspector:'Standard'Physical'Library' Interface'for'Full;System'Microarchitecture'and' Mul>;Physics'Simula>ons'

Transcription

1 Energy'Introspector:'Standard'Physical'Library' Interface'for'Full;System''and' Mul>;Physics'Simula>ons'! William!Song,!Saibal!Mukhopadhyay,!Arun!Rodrigues,!! and!sudhakar!yalamanchili! Georgia!Ins?tute!of!Technology,!Atlanta,!GA! Sandia!Na?onal!Laboratories,!Albuquerque,!NM! SPONSORS!

2 Major'Challenges'! A!modeling!methodology!and!infrastructure!for!full$system* applica/on*+*microarchitecture*+*mul/$physics*simula/ons*! Interac?ons!between!applica?ons!and!physical!phenomena!! Interac?ve!dynamics!between!mul?ple,!dis?nct!physical!phenomena,! e.g.,!temperature!and!reliability!! Interface*design!between!system/microarchitecture!models!and! physical!models!! Standard*library!and!API*interface! Back!Side!Air!Cooling!! Ease!of!ReMuse! Cu!heat!spreader! Tier!4! Tier!3! Tier!2! Tier!1! BT!substrate! PCB! 2

3 State'of'the'Prac>ce' 1. Current!prac?ces!(e.g.,!traceMdriven!simula?ons)!are!insufficient!at! scale!to!address!research!problems!at!the!intersec?on!of! applica?ons,!microarchitecture,!power,!thermal,!and!reliability,!etc.!!!we*need*holis/c*modeling*environment.* Applica>ons'! Architecture' Physics' 2. A!single!model!does!not!provide!all!necessary!details!and!modeling! capabili?es!for!different!research!problems.!!!we*need*a*framework*that*is*open*to*the*composi/on*of*** *************new*or*updated*physical*models!(universal).* * *The*physical*models*and*simulators*should*not*have* * *******cross$dependency*in*implementa/ons*(standard!interface).* 3

4 Problem'Descrip>on' In!this!talk,!we!address!two!major!problems:! 1. Implemen>ng'integrated'power;thermal;reliability'simula>ons'! Why!do!we!need!microarchitecture,*mul/$physics*co$simula/on! environment!(vs*conven/onal*trace$driven*simula/ons)?! Simulations Performance* Counters* Power Modeling Power*Traces* Thermal Modeling Thermal*Traces* Instantaneous* Failure*Rates* Wear Modeling and Physical Configuration Package Configuration and Floorplanning Benchmarks Configuration Functional Emulation (Frontend) Instruction Stream Timing Simulation Access Counter Statistics Leakage Feedback Leakage Energy Power Modeling +! Dynamic Energy Floor-plan Power Thermal Modeling Clock Frequency Voltage Multi-Physics Interactions Management Algorithms Controller Trace&driven+simula0ons vs Full&system+integrated+simula0ons+ + Which+simula0on+model+should+we+use?+ Cumulative Failure Rate Reliability Modeling Floor-plan Temperature 4

5 Problem'Descrip>on'(cont.)' 2. Incorpora>ng'Various'Implementa>ons'of'Modeling'Tools'via' Standard+Libraries+! A!single!model!doesn t!provide!all!necessary!details!or!modeling! capabili?es!for!different!research!problems.!! Open'to'Integra>on:!Can!we!standardize*the*interface*and* integra/on!of!models?!!!so]ware!engineering!problem! McPAT, DSENT, etc. HotSpot, 3D-ICE, etc. BTI, TDDB, etc. Noise, Delay, etc. Power Library Thermal Library Reliability Library Other Libraries Standard'Mul>;Physics'Library'Interface' 'Simula>on'Framework' 5

6 General'Prac>ces:'Trace;Driven'Simula>ons' Simulations Performance Counters Power Modeling Power Traces Thermal Modeling Thermal Traces Wear Modeling Instantaneous Failure Rates Trace$driven*simula/on!is!the!most!commonly! used!approach!to!analyze!physical!impacts!of! microarchitectural!opera?ons.! Each!step!is!an!independent!simula?on.! This!approach!does!not!capture!feedback* interac/ons!between!the!models! (e.g.,!temperature!!leakage!power!feedback).! This!simula?on!approach!can!only!be!used!to! model!monotonous*processor*execu/ons!! (i.e.,!steadymstate!analysis).! Ref:*A.*Coskun,*T.*Rosing,*K.*Mihic,*G.*Micheli,*and*Y.*Leblebici,* Analysis*and*Op/miza/on*of*MPSoC* Reliability, *JOLPE,*Jan.*2006.** 6

7 Full;System''&'Mul>;Physics'' Co;Simula>ons'! We!propose!an!integrated!microarchitecture!and!mul?Mphysics! simula?on!model:! Benchmarks Functional Emulation (Frontend) Instruction Stream Management Algorithms Configuration Timing Simulation Clock Frequency Controller and Physical Configuration Package Configuration and Floorplanning Access Counter Statistics Leakage Feedback Leakage Energy Power Modeling +! Dynamic Energy Floor-plan Power Thermal Modeling Voltage Multi-Physics Interactions Cumulative Failure Rate Reliability Modeling Floor-plan Temperature 7

8 Library'Integra>on'and'Mul>;Physics'Interac>ons'! By!standardizing!individual!tools!into!a!set!of!libraries,!linking* library*models*becomes*a*problem*of*describing*physical* interac/ons,!instead!of!the!so]ware!integra?on!of!tools.! Benchmarks Functional Emulation (Frontend) Instruction Stream Management Algorithms Power Models (Power Library) Cacti/McPAT, Orion/DSENT, etc. and Physical Configuration Package Configuration and Floorplanning Thermal Models (Thermal Library) 3D-ICE, HotSpot, Microfluidics, etc. Configuration Timing Simulation Access Counter Statistics Leakage Feedback Leakage Energy Power Modeling +! Dynamic Energy Floor-plan Power Thermal Modeling Clock Frequency Voltage Multi-Physics Interactions Controller Cumulative Failure Rate Reliability Modeling Floor-plan Temperature Wear Models (Reliability Library) NBTI, TDDB, HCI, Electromigration, etc. 8

9 SoPware'Engineering'Problems'! With!mul?ple!models!integrated!into!the!same!framework,!there! are!several!engineering!problems!to!be!resolved:! 1. Unified'Processor'Configura>on:!! There!has!to!be!a!way!to!associate*different*physical*models* with*different*processor*components,!e.g.,!sram!vs.!logic!vs.! interconnect,!thermal!vs.!reliability,!etc.*! Different*physical*phenomena*are*characterized*at*different* levels*of*processor*abstrac/on,!i.e.,!package,!floormplan,! architectural!unit,!etc.! 2. Data'Synchroniza>on'and'Manipula>on:!! Physical!interac?ons/data!across!different!models!must!be! synchronized.! Ref:*W.*Song,*S.*Mukhopadhyay,*and*S.*Yalamanchili,* Energy*Introspector:*A*Parallel,*Composable* Framework*for*Integrated*Power$Reliability$Thermal*Modeling*for*Mul/core*Architectures, *ISPASS* (Short*Paper),*Mar.*2014.* 9

10 Associa>ng'Physical'Models'and'Processor'Components''! A!pseudo*component!is!a!physically* defined*unit!where!a!model!can! es?mate!physical!phenomena,!! e.g.!l2!cache!power.!! A!processor!is!configured!by! composing!pseudo*component* hierarchy.!! Libraries*are*a]ached*to*pseudo* components!and!simulate!different! physical!phenomena!at!different! levels! Pseudo Component (Floor-plan: Core0) Model Library = Reliability Library Pseudo Component (Source: Inst$) Model Library = Energy Library Instruction Cache Instruction TLB Floor7planning) Fetch Buffer Branch Prediction Pseudo Component (Floor-plan: Core1) Pseudo Component (Cores: Intermediate) Model Library = Reliability Library Pseudo Component (Source: Registers) Model Library = Energy Library Instruction Decoder Packaging) Architecture)Decomposi/on) Pseudo Component (Package) Instruction Window Data TLB Model Library = NULL Pseudo Component (Floor-plan: CoreN) Data)Reference)) (Physical)Interac/on)) Model Library = Reliability Library Pseudo Component (Source: ALUs) Model Library = Energy Library Register Files L1 Data Cache Model Library = Thermal Library Pseudo Component (Uncore: Floor-plan) Model Library = Reliability Library Pseudo Component (Source: L2$) Model Library = Energy Library ALU FPU ST LD L2 Data Cache On-Chip Network 10

11 Standard'API'Func>ons'! The!Energy!Introspector!framework!provides!a*set*of*API* func/ons!to!be!called!by!user!architecture!simulators.! while(simulation runs) {! do (architecture timing simulation); // User Architecture Simulation! sampling point) {! // Power Calculation! for(all architecture components to calculate power) {! EI_client->calculate_power(arch_component_id, current_time,! sampling_interval, access_counters);! }! // Thermal Calculation Models are internally synchronized.! EI_client->calculate_temperature(package_component_id, current_time,! sampling_interval);! // Reliability (Failure Rate) Calculation! for(all components to calculate reliability) {! EI_client->calculate_failure_rate(block_component_id, current_time,! sampling_interval);! }! // Probe any component to collect data! int err_code = EI_client->pull_data(component_id, current_time,! sampling_interval, data_type, &data);! // Apply execution control (i.e., voltage scaling)! int err_code = EI_client->push_and_synchronize_data(component_id, current_time,! sampling_interval, EI_DATA_VOLTAGE, &new_voltage);! }! }! 11

12 Energy'Introspector'is'An'Enabler.'! The!primary!goal!of!the!Energy!Introspector!is!to!enable!the! explora/on*at*the*intersec/on*of*microarchitecture,*power,* thermal,*and*reliability.!! We!provide!several!exemplary!studies:! 1. Mul/core**and*Microfluidics*Cooling*in*3D*ICs* 2. Power,*thermal,*and*throughput*regula/on*via*adap/ve*control* algorithms*in*mul/core*processors* 3. GPU*power*modeling*with*McPAT* 4. Life/me*reliability*characteriza/on*and*management*in*mul/core* processors* 12

13 Case'I:'Mul>core''and'Microfluidics' Cooling'in'3D'ICs'! How!much!leakage*power*saving!or!improvement*in*energy* efficiency!can!microfluidics*cooling*achieve!as!a!func?on!of! layering,!pinfin!geometry,!and!pumping!power?!! Energy!Introspector!captures!interac/ons*between*mul/ple* physical*metrics.* 1. Z.*Wan,*H.*Xiao,*Y.*Joshi,*and*S.*Yalamanchili,* Co$Design*of*Mul/core*Architectures*and*Microfluidic* Cooling*for*3D*Stacked*ICs, *Therminic,*2013.* 2. H.*Xiao,*Z.*Wan,*S.*Yalamanchili,*and*Y.*Joshi,* Leakage*Power*Characteriza/on*and*Minimiza/on*over* 3D*Stacked*Mul/$core*Chip*with*Microfluidic*Cooling, *SemiTherm,*2014.* 13

14 Case'II:'Power,'Thermal,'and'Throughput'Regula>on'via' Adap>ve'Control'Algorithms'in'Mul>core'Processors'! Adap/ve*control*algorithms!u?lize!the!DVFS!capability!of! microprocessors!to!regulate!power,!thermal,!or!throughput!to! constant!level.!! Energy!Introspector!provides!an! interface*to*apply*dynamic* execu/on*controls,!e.g.,!dvfs.! 1. N.*Almoosa,*W.*Song,*S.*Yalamanchili,*and*Y.*Wardi,* Throughput*Regula/on*in*Mul/core*Processors* via*ipa, *CDC,*2012.* 2. N.*Almoosa,*W.*Song,*S.*Yalamanchili,*and*Y.*Wardi,* A*Power*Capping*Controller*for*Mul/core* Processors, *ACC,*2012.* 14

15 Case'III:'GPU'Power'Modeling'Using'McPAT'! Basic!models!of!the!McPAT!(i.e.,!caches,!interconnects,!latches,! etc)!are!remorganized!to!configure!a!gpu!architecture.!! Energy!Introspector!is!configurable*to*model*different* microarchitecture!or!processor!designs.! 1. J.*Lim,*N.*Lakshminarayana,*H.*Kim,*W.*Song,*S.*Yalamanchili,*and*W.*Sung,* Power*Modeling*for*GPU* Architectures*Using*McPAT, *TODEAS,*June*2014.* 15

16 Case'IV:'Life>me'Reliability'Characteriza>on'and' Management'in'Mul>core'Processors'! Variance*Reduc/on:!Adap?ve!control!on!core!execu?on!reduces! variances!in!life?me!reliability!distribu?on!across!the!mul?core!dies! and!improves!overall!processormlevel!life?me!reliability.!! Energy!Introspector!provides!an*integrated*applica/on$ microarchitecture$power$thermal$life/me*reliability*simula/on.! Normalized+MTTF+ 1$ 0.9$ 0.8$ 0.7$ 0.6$ 0.5$ 100%$ 90%$ 80%$ 70%$ 60%$ Performability+Threshold+ 50%$ μ=1.0,σ=0.05$ μ=1.0,σ=0.10$ μ=1.0,σ=0.15$ μ=1.0,σ=0.20$ Normalized+MTTF+ 1$ 0.9$ 0.8$ 0.7$ 0.6$ 0.5$ 100%$ Prac4cal$Region$of$Life4me$ 90%$ 80%$ 70%$ 60%$ 50%$ Performability+Threshold+ μ=1.0,σ=0.20$ μ=0.80,σ=0.05$ 1. W.*Song,*S.*Mukhopadhyay,*and*S.*Yalamanchili,* Architectural*Reliability:*Life/me*Reliability* Characteriza/on*and*Management*of*Many$Core*Processors, *CAL,*2014.* 16

17 Conclusion'and'Future'Works'! In!general!prac?ces,!microarchitecture!and!physical!proper?es! have!been!analyzed!in!separate*models*and*simula/ons.!! Such!a!approach!is!difficult*to*capture*inter$dependency!between! various!physical!phenomena!and!their!impacts!on! microarchitecture.!! Therefore,!holis/c*modeling*and*simula/on*environment!is! essen?al!to!enable!the!explora?ons!at!the!intersec?on!of! applica?ons,!microarchitecture,!power/energy,!thermal/cooling,! reliability,!etc.!! Our!standard!library!interface!is!scalable!to!incorporate!further! physical!phenomena!and!their!models.! 17

18 Summary'! What'is'the'major'contribu>on'of''your'research?'! An!infrastructure!to!enable!integrated*applica/on,*microarchitecture,* and*mul/$physics*simula/ons,!based!on!library*implementa/on/ integra/on*of*physical*models.!!!integrated*infrastructure,*scalable*framework,*standard*api*! What'are'the'gaps'you'iden>fy'in'the'research'coverage'in'your' area?'! Lack!of!standards!in!using!physical!models!! Lack!of!parallel!implementa?on!of!computa?onally!intensive!models! or!large!coremcount!systems!! Fast!compact!models!for!thermal!and!power!delivery!! Need!agreement!on!power!models!across!technologies!! Need!of!higherMlevel!(applica?onMlevel)!models! 18

19 Summary'(cont.)'! What'is'the'bigger'picture'for'your'research'(i.e.,'synerge>c'or' complementary'projects)?'! Applica?onMArchitecture!CoMdesign!! MeasurementMbased!valida?on!infrastructure!! What'major'opportuni>es'do'you'see'for'cross;pollina>on' between'your'projects'and'others?'! Acquiring!new,!beier!physical!models!! Par?cipa?on!in!coMdesign!ac?vi?es,!e.g.,!architectureMapplica?on,! power!deliverympower!management!! PlajormMneutral!models!of!physical!behaviors!from!applica?ons!! Interac?on!with!compiler!and!run!?me!projects! 19

20 Summary'(cont.)'! What'is'one'thing'that'would'make'it'easier/possible'to'leverage/ use'the'results'of'other'projects'to'further'your'own'research?'! Standardiza?on!of!APIs!for!accessing/exercising!physical!models!at! mul?ple!levels!of!abstrac?on!! What'would'you'like'to'most'see'solved/addressed'other'than' what'you'are'working'on?'! Characteriza?on!of!fault!behaviors!as!a!func?on!of!physical!phenomena! and!applica?on!demand!! Higher!level!applica?on!models!to!drive!powerMthermalMreliability! analysis! 20