###### tags: `homework` `sysprog2017` 2017q3 Homework1 (phonebook) === contributed by <`Jetudie`> --- 題目： [C02: phonebook](https://hackmd.io/s/HJJUmdXsZ) ## 開發環境 列出CPU資訊 `$ lscpu` (要更詳細了解也可以用 `$ cat /proc/cpuinfo` ) ``` Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 2 Core(s) per socket: 2 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 60 Model name: Intel(R) Core(TM) i5-4200M CPU @ 2.50GHz Stepping: 3 CPU MHz: 799.865 CPU max MHz: 3100.0000 CPU min MHz: 800.0000 BogoMIPS: 4988.06 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 3072K NUMA node0 CPU(s): 0-3 ``` 列出系統相關資訊 `$ uname -a` ``` Linux michael-Lenovo-IdeaPad-Z510 4.10.0-35-generic #39-Ubuntu SMP Wed Sep 13 07:46:59 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux ``` 清空 cache, 檢視一下資源 (只開 terminal 的情況) `$ echo 1 | sudo tee /proc/sys/vm/drop_caches` `$ free` ``` total used free shared buff/cache available Mem: 8087436 281492 7619884 61484 186060 7543304 Swap: 10000380 0 10000380 ``` --- ## 效能 #### 一開始的效能 `$ make plot` ![original](https://i.imgur.com/KtGVjMc.png) `$ make cache-test` ``` Performance counter stats for './phonebook_opt' (100 runs): 35,407 cache-misses # 46.277 % of all cache refs ( +- 0.28% ) 76,511 cache-references ( +- 0.37% ) 88,826,649 instructions # 1.53 insn per cycle ( +- 0.00% ) 58,161,375 cycles ( +- 0.19% ) 0.128115937 seconds time elapsed ( +- 0.72% ) ``` ## 參考資料 1. [2016 年春季系統課程 Homework 1 解說 ](https://www.youtube.com/watch?v=ZICRLKf_bVw) 2. [cache 原理和實驗](https://hackmd.io/s/S14L26-_l) 3. [我的工具筆記](https://hackmd.io/s/SJluWzBhZ)