Linux Max threads limit and current thread count query

1, summary system limitations are:

/proc/sys/kernel/pid_max #查系统支持的最大线程数, usually very large, equivalent to the theoretical value
/proc/sys/kernel/thread-max
max_user_process (ulimit-u) #系统限制某用户下最多可以运行多少进程或线程
/proc/sys/vm/max_map_count
Hardware Memory Size


2. The Java Virtual machine itself limits:
-xms #intial java heap Size
-xmx #maximum java heap Size
-XSS #the stack size for each thread


3. Query the current number of threads or processes of a program
pstree-p ' ps-e | grep java | awk ' {print $} ' | Wc-l
or
pstree-p 3660 | wc-l


4. Query the current number of threads or processes used by the entire system

Pstree-p | Wc-l

1. Cat/proc/${pid}/status

2,pstree-p ${pid}

3,top-p ${pid} and press H or direct input top-bh-d 3-p ${pid}

Top-h
The handbook says:-h:threads Toggle
Add this option to start a top,top line to display a thread. Otherwise, it displays a process one line.

4, PS XH
The manual says: H Show Threads as if they were processes
This allows you to view all the threads that exist.

5. PS-MP <PID>
The manual says: M Show Threads after processes
This allows you to see the number of threads from a process.

Linux Max threads limit and current thread count query