2023q1 Homework7 (ktcp)

contributed by < PlusThousand0107 >

開發環境

$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ lscpu
Architecture:            x86_64
  CPU op-mode(s):        32-bit, 64-bit
  Address sizes:         39 bits physical, 48 bits virtual
  Byte Order:            Little Endian
CPU(s):                  12
  On-line CPU(s) list:   0-11
Vendor ID:               GenuineIntel
  Model name:            Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
    CPU family:          6
    Model:               158
    Thread(s) per core:  2
    Core(s) per socket:  6
    Socket(s):           1
    Stepping:            10
    CPU max MHz:         4100.0000
    CPU min MHz:         800.0000
    BogoMIPS:            4399.99

CMWQ

CMWQ 是 Workqueue 的一種重新實作，常用於需要異步執行的情況下，不過相較於 Workqueue ， CMWQ 著重在於以下幾個方面

1. 保持原始 Workqueue API 的兼容性
2. 能自動調整 worker pool 和 level of concurrency ，所以使用者在使用 API 時可以不需知道實作細節
3. 所有的 Workqueue 會共享 per-CPU unified worker pools ，提供靈活的 level of concurrency ，避免過多的資源浪費

壓力測試與比較

於本機對 seHTTPd 和 cserv 進行壓力測試

ab

ab -n 100000 -c 500 -k http://127.0.0.1:8081/

	Requests per second	Time per request (mean, across all concurrent requests)
seHTTPd	11118.94 #/sec	0.090 ms
cserv	21028.50 #/sec	0.048 ms

htstress

./htstress -n 100000 -c 500 127.0.0.1:8081/

	requests/sec	total time
seHTTPd	23557.609 #/sec	4.245 s
cserv	25272.884 #/sec	3.957 s

httperf

httperf --server 127.0.0.1 --port 8081 --num-conn 500 --num-call 200 --http-version 1.0

	requests/sec	connection rate
cserv	21856.5 #/sec	10928.2 conn/s