[wsl2] restrict wsl2 accessible hardware resources (cpu/ memory)

WSL2 Theoretically available Windows All managed within the system CPU、 Memory resources ;

But that brings a problem , namely ：

Sometimes we use WSL2 Just as a terminal window , Not too much CPU Or memory , But because of Linux Kernel memory management mechanism , It will try to cache some file pages that have been read , It will not be released for a long time . And this part of the file page will not be Windows Recycling , Lead to WSL2 Taking up too much memory , and Windows Instead, there is no memory available ;

For this scenario , Can be in %UserProfile% Next create a .wslconfig File to configure ：
（%UserProfile% Usually C:\Users<$username>\）

[wsl2]
processors=4
memory=4GB
swap=4GB

• processors As the name suggests, it means to limit CPU The core number （ Will be reflected in /proc/cpuinfo On equal nodes ）
• memory Is the total available memory size （ Will be reflected in /proc/meminfo On equal nodes ）
• swap Is the total size of the swap space （ Will be reflected in /proc/meminfo On equal nodes ）

Save your changes and close WSL, And reopen the window to start ：
wsl --shutdown Ubuntu

Look at the nodes , In force ：

ryan /mnt/c/Users/ryan $ cat /proc/cpuinfo | grep processors
ryan /mnt/c/Users/ryan $ cat /proc/cpuinfo | grep processor
processor       : 0
processor       : 1
processor       : 2
processor       : 3

ryan /mnt/c/Users/ryan $ cat /proc/meminfo | grep Total
MemTotal:        4028148 kB
SwapTotal:       4194304 kB
VmallocTotal:   34359738367 kB
HugePages_Total:       0