What is Lwp and NLWP?
LWP = Light weight process or Thread ID NLWP = Number of light weight process [root@docker ~]# ps -eLf | head -1; ps -eLf | egrep “2662|2663” |grep -v grep UID PID PPID LWP C NLWP STIME TTY TIME CMD root 2662 2624 2662 0 1 09:44 pts/2 00:00:00 vim a.txt root 2663 2582 2663 0 1 09:44 pts/1 00:00:00 vim b.txt.
What is NLWP?
NLWP is the number of threads in the system for the underlying process. In the ps output above, rsyslogd (pid 852) has 4 threads, NetworkManager (pid 874) has three threads and polkitd (pid 893) has two threads. The -L option gives an idea about the total number of concurrent threads in the system.
What is LWP thread?
The LWP appears to be a virtual processor on which the application can schedule a user thread to run, to the user-thread library. Each Light Weight Process is attached to a kernel thread, and it is kernel threads that the operating system schedules to run on physical processors.
What are ps columns?
About the output fields of the ps command in Unix
| Column Header | Contents |
|---|---|
| TIME | Total CPU usage |
| TT or TTY | Terminal associated with the process |
| UID or USER | Username of the process’s owner |
| WCHAN | Memory address of the event the process is waiting for |
How does threading work Linux?
To the Linux kernel, there is no concept of a thread. Linux implements all threads as standard processes. The Linux kernel does not provide any special scheduling semantics or data structures to represent threads. Instead, a thread is merely a process that shares certain resources with other processes.
What is TTY process?
The tty command of terminal basically prints the file name of the terminal connected to standard input. tty is short of teletype, but popularly known as a terminal it allows you to interact with the system by passing on the data (you input) to the system, and displaying the output produced by the system.
What is light weight process LWP Why do we use it?
Light-Weight Process (LWP) is a method of achieving Concurrency. In the traditional meaning of the term, as used in Unix System V and Solaris, a LWP runs in user space on top of a single kernel thread and shares its memory address space and system resources with other LWPs within the same process.
What is LWP in Solaris?
The LWP is the kernel data structure providing the kernel infomation. The real execution unit or flow is kernel thread.
What is TTY in ps output?
A TTY is a computer terminal. In the context of ps , it is the terminal that executed a particular command. The abbreviation stands for “TeleTYpewriter”, which were devices that allowed users to connect to early computers.
What is sz in ps output?
START or STIME. Time when the process started. SZ. Virtual memory usage. TIME.
What is ps aux?
The ps aux command is a tool to monitor processes running on your Linux system. A process is associated with any program running on your system, and is used to manage and monitor a program’s memory usage, processor time, and I/O resources.
What is a thread vs process?
Process means a program is in execution, whereas thread means a segment of a process. A Process is not Lightweight, whereas Threads are Lightweight. A Process takes more time to terminate, and the thread takes less time to terminate. Process takes more time for creation, whereas Thread takes less time for creation.
What is RSS in ps command?
PS service RSS stands for Resident Set Size and shows how much RAM is utilized at the time the command is output. It also should be noted that it shows the entire stack of physically allocated memory.