Questions tagged [process]
A process is an instance of a computer program that is being executed.
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What is the colon in postgres' process command-lines?
For example Postgres process command-lines are like
postgres 794 1 0 Nov06 ? 00:00:03 /usr/pgsql-9.3/bin/postgres -D /var/lib/pgsql/9.3/data -p 5432
postgres 857 794 0 Nov06 ? ...
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Can a process share unused memory with others?
I want to run about 200 processes with my experiments. Every of them really needs less than a GB:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
24688 rinkman 20 0 ...
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Why does ps not exit when listing full command line arguments?
Any time I attempt to run the ps command or another similar command in a way that would make it output the arguments for any process, the command runs and produces output, but then freezes, entering ...
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1
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What signal do bg and fg send?
I know that ctrl + z changes a process from foreground to background - as suspended - through SIGTSTP. I am able to re-run that background suspended process through either fg or bg as required.
...
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jobs command: How report all the done/finished processes, but at anytime?
About background processes, for simplicity if for example are executed:
sleep 300 &
sleep 350 &
sleep 360 &
sleep 400 &
sleep 800 &
When is executed jobs -l, in the output is ...
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1
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Unable to get PID on a Listening port for Solaris
I'm using solaris
SunOS myhost4 5.11 11.4.42.117.3 sun4v sparc sun4v non-global-zone
I'm sure that port 7777 is in use as the telnet is successful as below:
$ telnet myhost4 7777
Trying 10.23.52.219.....
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1
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Understanding maps file in /proc directory for a process
In linux, when I access /proc for a particular program it shows memory mapping for the program in maps file.
Something like this:
address perms offset dev inode ...
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1
answer
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service start automatically on debian 10
I have server with debian 10, previously on this server unbound service installed.
Today I noticed that the service is reset every minute.
I even deleted the file /lib/systemd/system/unbound.service ...
- 569
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How does Linux create/manage processes assigned through pgid? [duplicate]
I am reading this post:
Using job control in the shells
About pgid and ppid it indicates:
PGID
Each process in a process group shares a process group ID (PGID),
which is the same as the PID ...
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ShellScript: How to create manually a parent process and their children process? [duplicate]
I am reading this post:
Using job control in the shells
About ppid it indicates
PPID
A process that creates a new process is called a parent process;
the new process is called a child process.
The ...
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1
answer
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Reparenting a process
I create a Linux Kernel Module and I try to find a way to re-parent a given process or change a given process PID. Is there any way of doing that?
I found the following link but I could not make it ...
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0
answers
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List down Linux parent processes having more than 5 Child Processes [duplicate]
I want to list all the parent processes on my machine which are having more than a number say(5) child process. Kindly suggest a command to achieve this.
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Is the stack of a forked process shared with its parent? [duplicate]
Is the stack of a forked process shared with its parent?
If so, does this happen via shared copy-on-write pages?
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Signals table in /proc/[PID]
I am trying to overwrite or change the Signals of a process. As I guess there is a table of signals in every process separately.
Is there anything like that in the /proc folder?
Thank you for your ...
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How to get NSPid on kernel 3.10
In kernel 4.1 and above, /proc/[pid]/status contains these 4 lines:
NStgid: 1
NSpid: 1
NSpgid: 1
NSsid: 1
This allow a process in parent namespace to know about that process' PID in all namespaces. ...
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1
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Where and how is the scheduler running? Can I "see" it? [duplicate]
The scheduler is not a thread but it's a kernel function, so there's no way to actually "see" what the scheduler is doing (I assume). These particular kernel parts are kind of invisible from ...
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Tuning with latency_ns
I would like to test the effect of latency_ns parameter on the execution time of a program. The program is a 16-thread MM implementation and the CPU is Ryzen with 8/16 (cores/threads). I also have ...
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Relation between SCHED_FIFO priority number and NI and PR
I use sudo chrt -f 1 ./run to set the lowest priority using the FIFO policy. While the application is running, I see the following PR and NICE values in top.
PID USER PR NI VIRT RES ...
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1
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Where is the process scheduler running? Can I track it?
Is the process scheduler "visible" at user space? Can I see it with ps? Maybe is it one of the kernel threads? If yes, how is it called? How can I "see" it?
It doesn’t exist as a ...
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Finding default process scheduler
Where in the Linux code, I can find the default process scheduler at the time of launching a process. For a running process, chrt shows SCHED_OTHER. On the hand, in various websites, I see that the ...
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Unable to kill node process on RedHat Linux
This is my OS:
[root@efendibey_live nginx]$ uname -a
Linux efendibey_live 3.10.0-1160.6.1.el7.x86_64 #1 SMP Tue Nov 17 13:59:11 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
[root@efendibey_live nginx]$ ...
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System-wide scheduling modification
Is there a way to change the process scheduling policy of the whole system? For example, I want to change the default SCHED_OTHER to SCHED_RR for all processes. The command chrt operates on a process. ...
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2
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chrt has no effect on changing scheduling policy
I would like to change the scheduling policy of a process via chrt, however, as you can see below, it has no effect on the systemd process. This is an example and I tried other processes, too. It ...
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4
answers
64
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How to prevent child process to interfere with bash prompt?
The application in question is DaVinci Resolve. I start it from terminal. And when I close it, the message "Socket Disconnected" from the app is written to the terminal output. Then the bash ...
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Ubuntu closes all the applications when lid is closed or suspended
I have been facing this issue for a while now.
Every time I close my lid, my Ubuntu 21.10 closes all the applications that were open before I closed the lid.
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Systemd ignores notify PID when similar service is running
I have two services that are almost identical, except for the paths. Each service runs a Minecraft server on tmux. Here's the generic unit file:
[Unit]
Description=<description>
After=network....
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2
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1
answer
253
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Resume killed job
I accidentally closed a terminal window where I had limited the cpu usage of a parallel job. Now, if I ps -e S in a new terminal window, I can see that job as:
311029 pts/0 TN+ 275:25 jobname
Is ...
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3
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Has Linux always separated User and Kernel space?
I was thinking back to my introduction to programming recently and remembered writing a C++ program that deliberately read and wrote to memory addresses at random. I did this to see what would happen....
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How is the execution state saved at context switch in x86-64 linux kernel?
Since the TSS does not store the values of the registers in x86-64, how are those saved when the context switch occurs?
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How do I disable csd-wacom?
I would also like to know how to permanently disable csd-wacom since I don't have a Wacom tablet and csd-wacom is wasting resources and the question regarding how to disable it wasn't answered.
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1
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Apache server sometimes gets stuck for minutes with requests getting backlogged and waiting too much to be processed
I've got a production server with Apache 2.4.38 on Debian 10 and sometimes the web server doesn't function properly and doesn't immediately send a response to the HTTP requests it gets (All virtual ...
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26
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How do I capture binary output from a process different from the console output?
I'm currently able to launch a process from within Java's ProcessBuilder, which continually appends to a (binary) file output.WAV, and is continually dumping lines of console updates. That works ...
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is it possible to get disk usage per process using top and ps command?
I am trying to find out if is possible to get disk usage using the above mentioned commands in terminal but no luck. Can anyone help? if there is not, then is there any other command that can I use to ...
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2
answers
238
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How to get the PID of a program executed in a bash script with remote linux
I'm on a Mac computer accessing by ssh a linux machine to run simulations. I'm currently running multiple commands in parallel (I put them in background with &), when they finish I extract the ...
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1
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How does the fork system call work?
If we look at the example
#include <stdio.h>
#include <unistd.h>
void main(){
int pi_d ;
int pid ;
pi_d = fork();
if(pi_d == 0){
printf("Child Process B:\npid :%d\nppid:%...
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if a device driver is called multiple times, does the kernel create multiple processes?
what happens if a device driver is called open("/dev/mydrievr") multiple times by multiple programs?
is a process created for each call?
is it possible to instantiate a thread instead of a ...
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Minimal "setuid" demo not working as documented? [duplicate]
Context
The setuid utility, according to both Unix and FreeBSD documentation, allows a process to run with an effective permission level of the executable file, instead of the real permission of the ...
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How do I find the PID of a specific shell script that is sleeping?
I understand I can use pgrep -fl example.sh to find the PID of the script example.sh, but this doesn't work if example.sh is something like the following:
(while true; do
sleep 5
done) &
...
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1
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Discover root cause of find command running
This morning I came in and noticed my hard drive light was solid on. This was unusual so I ran iotop and saw a find command was searching my filesystem.
I decided to run ps auxZ to dump the processes ...
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0
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How to find all the unclosed files of a process?
I'm trying to debug if my app keeps opened files somewhere in the code. I thought of using strace for that but all of the previous topics (like this one) were talking about only opened files. While ...
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remove on stale pid file after power failure to allow software startup via systemd service
i got such situation
there is a power failure
the UPS battery is drained during power failure
the servers in rack are shut off from power lose
power is restored
servers powering up and their os'es ...
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2
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Is /proc/sys comparable to the Windows registry?
Does Linux's /proc/sys expose similar functionality to that of the Windows Registry or are they incomparable?
From what I've seen, both allow the user to change various arcane system functions by ...
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Memory sections of a process
According to the textbook "operating systems concepts 9th ". The memory of a process is divided into different sections. One of the sections is the data section. The book states that :
...
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What starts threads in Linux OS?
I am currently investigate a question related to threads in the Linux OS. I know that processes are started by the scheduler in Linux Kernel, but what starts threads inside a process - Linux Kernel ...
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1
answer
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Bash - List PID's of processses which have more than six descendant processes?
Suppose there is a process dummy.sh whose pid is 101 & has seven descendants:
pstree -pc 101
dummy(101)──dummy(102)──dummy(103)──dummy(104)──dummy(105)──dummy(106)──sleep(107)
But how to fetch ...
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38
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Changing CPU affinity on they fly has no result
so I am creating my own script to set priority and cpu affinity for important processes on my system, and I tried using taskset command, but it seems to do nothing.
Here's sample:
import psutil
import ...
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How can a process have this value for a command? [duplicate]
I'm wondering how a process can have this command line
~ % pgrep -ai dhc
1681 dhcpcd: [master] [ip4] [ip6]
Same for ps
~ % ps -o command 1681
COMMAND
dhcpcd: [master] [ip4] [ip6]
This seems to come ...
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40
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Process state "S+" [duplicate]
One of the processes state in Ubuntu is interruptible sleep, which is denoted by "S" . I have two questions regarding this state :
What is the exact meaning of the word interruptible in ...
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47
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Does the regex engine have an associated executable?
I'm working with a tool that uses a whitelist to allow certain commands to be executed. The whitelist works using file paths like so:
command1=/bin/echo
command2=/bin/sed
...
The problem is commands ...
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1
answer
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Linux server: How does memory get allocated to parallel processes?
I'm a complete newbie, so please excuse my ignorance and/or potentially wrong terminology.
I'm using an Ubuntu server through ssh for brain image processing (one command with several programs, ...
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