Computer-Orgnization project2

NVmain-gem5

info

• 討論筆記

• project 為外部與 container 連通的 volume
• /project/result/ 為個別問題的指令與結果存放的地方
• 修改檔案可在 git log 修改紀錄中找到
• 問題 「write-through」相關檔案在 q5-write-through branch 中，其餘問題都在 master
• gem5 與 NVmain 的 build 都設為 gitignore

TODOs

• Q0: Gem5 + NVmain Build-up
• Q1: Enable L3 last level cache in GEM5 + NVmain
• Q2: Config last level cache to 2-way and full and full-way associative ache and test performance.
• Q3: Modify last level cache policy based on RRIP
• Q4: Test the performance of write back and write through policy based on 4-wau associatve cache with isscc_pcm

  • see branch: q5-write-through. (accidentally named it q5 insteed q4)

• Bonus
  • Design last level cache policy to reduce the energy consumption of pcm_based main memory
  • Baseline: LRU

  • I don't have enough time... JustGiveUp QQ

Solutions

Q0 (Build up)

I use docker container to simulate the ubuntu:18.04 env
then just 跟著教學做

Q1 (Enable L3)

• gem5/configs/common/Caches.py
• gem5/configs/common/CacheConfig.py
• gem5/configs/common/Options.py
• gem5/src/cpu/BaseCPU.py
• project/gem5/src/mem/XBar.py

Q2 (2-way assoc and full-way assoc)

加上參數

--l3_assoc=2

Q3 (change to RRIP)

gem5/configs/commonCaches.py 中的 L3 Cache 加入: \

replacement_policy = Param.BaseReplacementPolicy(RRIPRP(),"Replacement policy")

gem5/src/mem/cache/replacement_policies/ReplacementPolicies.py 中列出了所有 Policy

Q4 (write through)

重點：BaseCache::writecleanBlk()
在 write hit 後，生成 writeclean packet 送給 writebacks
writeclean 會一路往下 writeback 直到 memory \

Bonus

JustGiveUP

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I am the bone of my computer.
Steel is my body, and coffee is my blood.
I have viewed over a thousand code.
Unknown to writeback.
Nor known to writeclean.
Have withstood pain to write many code.
Yet, those hands will never hold anything.
So as I pray, unlimited COFFEE works.