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5
votes
1answer
31 views

Systemd and process spawning

Don't normally post here but I am ripping my hair out over this one. I have a Python script that forks when it launches, and is responsible for starting a bunch of other processes. This script used ...
0
votes
1answer
485 views

Very large values for utime and stime for foo. Is foo still running?

I am running a program foo It has been running for close to 30 days now (even more) Until around 10 days ago (I cannot be very exact) it used 100% of one cpu on my dual core laptop (it was at the ...
1
vote
0answers
21 views

Find the creator of a task

I would like to find the creator task of an arbitrary task in the Linux kernel. However, I am not sure, if there is a way to do this in general. Normally, you can find the creator of a task via the ...
0
votes
1answer
62 views

Why PPID is different when opening from terminal and when opening by doubleclicking

I am using Linux. When i opened gedit program in gnome-terminal by gedit command it has opened the graphical gedit text editor. then the gedit has PPID bash ...
0
votes
1answer
50 views

killing a job running in the background

I have started running a long job by creating a script that executes several commands on 20 or so datasets sequentially. I began in the xterm window with $ script.scr then typed <ctrl-Z> ...
1
vote
1answer
79 views

Orphan process's parent id is not 1 when parent process executed from GNOME Terminal

I start a new process from GNOME Terminal and then this process fork a child. But when I killed the parent process the orphaned process's parent id became something other than 1 which represent init ...
12
votes
2answers
9k views

How to Throttle per process I/O to a max limit?

I'm looking for a way to limit a processes disk io to a set speed limit. Ideally the program would work similar to this: $ limitio --pid 32423 --write-limit 1M Limiting process 32423 to 1 megabyte ...
0
votes
0answers
40 views

isolcpus doesn't work on Ubuntu 14

I added isolcpus=0 to the end of the following line to the file /etc/default/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash isolcpus=0" The idea, as I understand it, is to reserve core 0 from having ...
3
votes
1answer
28 views

Set the affinity of a process from a shell script as it is being launched

I have a script (.sh) where I launch applications like this #!/bin/sh ./application1 configuration1.cfg param1 param2 param3 & sleep 2 ./application2 configuration2.cfg param1 param2 param3 ...
0
votes
2answers
37 views

What are some practical purposes for using renice? [closed]

I'm having a hard time finding a purposeful need for using renice more often, and I would like to know if there are any scenarios in which using process prioritization and adjusting it on-the-fly has ...
251
votes
9answers
106k views

When should I not kill -9 a process?

I am always very hesitant to run kill -9, but I see other admins do it almost routinely. I figure there is probably a sensible middle ground, so: When and why should kill -9 be used? When and why ...
1
vote
0answers
81 views

Start command and stop command in terminal on keyboard (hotkey) shortcut press?

I have seen How to execute a script in shell when a shortcut key is pressed, but that is not what I want. If you have used recordmydesktop, you may have noticed the following in its manual: After ...
0
votes
1answer
53 views

linux + top command

I run the top command on my linux machine and I see that vim command take like 99.5% CPU PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND ...
4
votes
6answers
1k views

grep invading my ps [duplicate]

When I'm checking for some process, I usually write ps aux | grep myprocess And sometimes I get the output of eimantas 11998 0.0 0.0 8816 740 pts/0 S+ 07:45 0:00 grep myprocess if ...
13
votes
6answers
10k views

How to make a process invisible to other users?

How could you launch a process and make it invisible to the top command? The process is started by a normal user (not root), and should not be visible to other normal users.
4
votes
3answers
105 views

Disallow File IO for a process except for FIFOs

How do you start a process that cannot do any file IO (opening / closing files, creating / deleting files, reading / writing files, etc.), except to read and write to pre-created FIFOs? (chroot will ...
4
votes
2answers
120 views

Can I attach a GUI process to a “surrogate X server”?

I have been in a situation where my desktop has crashed and become unresponsive. (In my case it was the Cinnamon DE, and I have yet to try cinnamon --replace from the commandline, BTW) I was using a ...
0
votes
3answers
69 views

Idiomatic way to kill -9 only if “graceful” way doesn't work?

Is there a common way or existing utility to do the following? kill a process Give it a few seconds to shut down gracefully kill -9 it if it hasn't stopped
2
votes
2answers
123 views

gracefully terminating processes with killall <processname>

I am using several instances (profiles) of Icedove (Thunderbird) and when I need to close all of them, I use: killall icedove According to man killall, if no signal name is specified, SIGTERM is ...
0
votes
1answer
101 views

Why kernel threads are treated as processes

In output of the ps command like the one below (kthreadd,ksoftirqd,kworker) , i can see that there are some processes that don't have an executable file and i find out that's because they are kernel ...
3
votes
1answer
43 views

create a realtime machine by assigning CPU cores to critical processes

I'm using an Udoo board for running two critical processes. It can run Ubuntu ARM edition and it has a Quadcore processor. I need to set the affinity of all the processes afinity running and the ones ...
13
votes
9answers
10k views

Ensure a process is always running

I started hosting sites a while back using Cherokee. For external sources (FastCGI, etc) it has an option to launch the process if it can't find one running on the designated socket or port. This is ...
7
votes
2answers
1k views

Simulate an unkillable process in D state

For catastrophe testing scenarios on out server environment we're looking for an easy way to make a process stuck in D (uninterruptible sleep) state. Any easy ways? An example C sample code would be ...
28
votes
4answers
2k views

python vs bc in evaluating 6^6^6

I am evaluating the expression 6^6^6 using python and bc separately. The content of the python file is print 6**6**6. When I execute time python test.py, I get the output as real 0m0.067s ...
4
votes
1answer
67 views

How to detect a desktop application hanging

I want to write a script that will detect whether a particular desktop application is responding and kill it. Is this possible? I know I've seen the GNOME desktop put up a "Application is not ...
0
votes
0answers
403 views

Detach a process from Sh (not Bash) or “disown” for Sh (not Bash)

Consider a shell script executed by Sh, not Bash (and I can't change it, and can't use a shebang, it's ignored). The & operator works, but disown $! does not and makes Sh complains “disown: not ...
75
votes
2answers
8k views

How does Linux “kill” a process?

It often baffles me that, although I have been working professionally with computers for several decades and Linux for a decade, I actually treat most of the OS' functionality as a black box, not ...
5
votes
2answers
121 views

How can I see i/o stats for a briefly running process?

For long running processes like init, I can do things like $ cat /proc/[pid]/io What can I do if I want to see stats for a briefly running process such as a command line utility like ls? I don't ...
5
votes
3answers
46k views

How can I see what processes are running?

I use Ubuntu Server 10.10 and I would like to see what processes are running. I know that PostgreSQL is running on my machine but I can not see it with the top or ps commands, so I assume that they ...
3
votes
1answer
256 views

Process management and pkill

I've been studying process management using shell scripts and I'm starting to realise how difficult it is to make sure that it's done right. For example, you can record the PID of a program to a ...
1
vote
3answers
72 views

How can i get the process with the biggest pid?

How can I get the process with the biggest pid using ps?
3
votes
1answer
148 views

What's the correct value to base the maximum number of CPU's to sched_setaffinity to?

I have some confusion as to what's the correct value to use for the number of CPU's I can use to make a CPU_SET for a sched_setaffinity call on my system. My /proc/cpuinfo file: processor : 0 ...
4
votes
1answer
189 views

SIGKILLing after a grace period

I've seen a lot of process managers that try to do this. It was my understanding that you should only use SIGTERM to kill a process. The process could take an unknown amount of time to clean up after ...
0
votes
1answer
42 views

How can I make my command more susceptible to system slowdowns so as to use it as a visual QoS widget on my desktop?

I had some system slowdown event1 after mistakenly using a command so I thought I could use a desktop "widget" to visually show quality of service or at least show when QoS was degraded and get some ...
2
votes
1answer
64 views

how to know the use of my applications?

I want to know how long my programs have been used. For example if I use my web browser I want to know the start and the close time to obtain a total of use time. Basically I want to know when an ...
2
votes
1answer
108 views

kernel event listener

I wonder if there is something similar to an event listener in UNIX that a program can subscribe to? Specifically I want to know: Start and end times of a user session Start and end of the ...
5
votes
2answers
293 views

Process owner vs process user (Gnome's system monitor)

Gnome's system monitor has a "User" column in the Processes tab. There's also an "Owner" column, (that seems to be hidden by default). Most of the processes have the same values on both columns. ...
3
votes
3answers
8k views

What is the difference between ps and top command?

What is the difference between ps and top command ? I see that both can display information about running processes . Which one should be used when ?
11
votes
2answers
1k views

What does a niceness value of (-) mean?

According to the man page, and wikipedia; nice ranges from -20 to 20. Yet when I run the following command, I find some processes have a non numerical value such as (-). See the sixth column from ...
6
votes
3answers
9k views
4
votes
2answers
414 views

How can I synchronize processes started in different TMUX panes?

Consider this: tmux split-window -d program1 program2 # this program depends on some side effects produced by program1 In this case, program2 will start before program1 is ready. program1 will send ...
2
votes
2answers
1k views

`[java] <defunct>` with defunct children -> Any way to collect them?

Relating to question : What if 'kill -9' doesn't work? I have following situation : zombie process with threads, not collected by init : [root@Arch64]# ps auxH | grep java gwpl 569 ...
4
votes
1answer
151 views

Reporting cpu hogs

Once in a while some program (ok, usually it's firefox) will start eating up nearly 100% of a processor's cpu time, heating up the processor and driving down by laptop's battery life. Since it's not ...
2
votes
5answers
397 views

Replace instance of process in place?

I suspect this is not doable just because of the security implications, but here's what I'd like to do. Basically we run a bash shell-script on our CentOS server that calls Program-A (in our case ...
1
vote
3answers
255 views

How do I start a server via ssh and have it run after I log out?

I ssh into a virtual server and start up a web server. Everything runs as expected. But when I close my terminal on my laptop, the process dies on the virtual server. How do I fix this?
4
votes
1answer
186 views

What is the default or most commonly used multiprocessing model in Linux? Symmetric or Asymmetric?

What the multiprocessing model for Linux? Is there a default or most commonly used model? Is it similar or very different from say BSD or even the MS Windows kernel? If SMP is used normally, can ...
3
votes
1answer
169 views

Better way to kill all processes with a handle to some file

This kills every process with a handle to file /foo/bar (in bash): lsof /foo/bar 2>&1 | grep "/foo/bar" | sed "s/ */\\t/g" | cut -f 2 | while read PID; do kill $PID; done This does not ...
6
votes
3answers
1k views

Simple queuing system?

Given a commodity PC, we would like to use it to execute some tasks in the background round the clock. Basically, we would like to have commands like: add-task *insert command here* list-tasks ...
18
votes
1answer
8k views

What is the maximum value of the PID of a process?

What is the maximum value of the PID of a process? Also, is it possible to change the PID of a running process?
3
votes
2answers
3k views

How to find how many cores a process is using?

I have a eight core machine. How can I find out how many cores are used by processes that I see in htop?