A process is an instance of a computer program that is being executed.

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How can process doing “vfork without exec” end up in a long uninterruptible sleep?

In this answer user suggests that Normally, Uninterruptible sleep should not last long, but as under windows, broken drivers or broken userpace programs (vfork without exec) can end up sleeping ...
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402 views

What causes /proc/<pid>/* resources to become owned by root, despite the procs being launched as a normal user?

I've noticed that some procs, such as bash, have their entire /proc/<pid>/ resources readable by the user who created that proc. However other procs, such as chrome or gnome-keyring-daemon, have ...
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Why pidof and pgrep are behaving differently?

I have a init script in /etc/init.d/myservice for initialize a service like this: ... start() { ... daemon /usr/sbin/myservice ... } stop() { ... pgrep myservice pidof myservice ps -ef ...
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Processes do not respond to my signals

I have a strange behavior on my system. When I invoke a command in the shell (bash version 4.2.45(1)-release), say top or cat, the running program (the process) does not respond to Ctrl+C. I even ...
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Difference between poll_s and ep_poll WCHAN in ps output

When I issue ps -elf|grep python for example on my system, I see these: 1 S 1000 6020 6008 0 80 0 - 9914 poll_s Jul12 ? 00:00:01 python manage.py run_gunicorn -t 3600 -w 8 -b ...
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399 views

What is /proc/<pid>/net/dev?

I'm interested in per-process network I/O counters, like those in /proc/net/dev and found what I thought was it under /proc/<pid>, i.e. /proc/<pid>/net/dev. But it seems that was too easy ...
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How to view a specific process in top

Are there any relatively strightforward options with top to track a specific process? Ideally by identifying the process by a human readable value? e.g. chrome or java. In other words, I want to view ...
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186 views

Is the Unix process scheduler itself a process?

Is the Unix process scheduler itself a process, or does it piggyback on other processes in the same way a system call does (running kernel code in the user process with the kernel bit set)?
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410 views

How disk IO priority is related with process priority?

I'm running software that overloads disk IO sometimes. I don't need fast response from that software, I need fast response from other applications, so I could set low process priority for that. I want ...
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Get CPU usage for single process

I've got a problem getting a real-time CPU usage of a single process (by its PID). I'd like to setup a watchdog for the CPU usage of a process because it's suddenly reaching 100% of the CPU usage ...
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315 views

Can I add to my groups in the current (shell) process? [duplicate]

If I add myself to a group, it applies only to newly launched processes. Actually it's more restricted than that; it seems to apply only to new logins. I'm not sure what the exact mechanism is, but ...
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605 views

How to know which commands are executed when I do something in GUI

This is for academic purpose. I want to know which commands are executed when we do something in GUI, for example creating a folder. I want to show that both the mkdir shell command and create folder ...
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How does forking affect a process's memory layout?

Please see the following figure showing the memory layout of a process: : When someone forks(), and a new task_struct is assigned, what happens to the addresses of the process? In more or less other ...
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Why is my C++ program killed by OS

I've compiled small C++ application for school project on my virtual ubuntu 11.04. However when I attempt to run it over some larger data set after ~20 sec the program is killed by OS. Killed ...
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3k views

Getting disk i/o statistics for single process in Linux

I need to monitor the I/O statistics of a process that writes to disk. The purpose is to avoid write rates too high for long periods. I know there's iostat tool to accomplish this task on a ...
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99 views

PID in arch-chroot is incorrect

I am trying to run a python script in a chroot (specifically, the chroot is created with arch-chroot). The python script relies on os.getpid(), but this seems to be returning an incorrect PID within ...
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set packet rate limit via iptables

I have a packet rate limit (max. 10 per seconds) which is set by my internet provider. This is a problem if I want to use the AceStream player, because if I exceed the limit I get disconnected. How ...
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What information can I find out about an eventpoll on a running thread?

Following on from a problem described in "How is it that I can attach strace to a process that isn't in the output of ps?" I'm trying to debug a process that hangs part way through. By using ...
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What does it mean exactly when a processes “Time” has stopped in top?

I'll be looking into why we're getting critical swap alerts, and I'll find something like: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ SWAP COMMAND 14683 user1 30 10 16.0g 772m ...
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Linux : See CPU usage by a process for the last second

vmstat 1 Above will print virtual memory statistics each seconds. It will also show the CPU utilization for last second. I have a web server at hand which runs httpd and MySQL. I need to find how ...
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353 views

How to monitor all executions of an executable over a time period

I know how to monitor a process. Commands like top and so forth can monitor the CPU time and memory usage for a given process instance. But say I expect a given executable to be run several times in ...
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I don't want other users see my processes in ps aux. I have root. It's Debian. How to use grsec?

I installed 'linux-patch-grsecurity2' and it has some sort of interface. ~$ sudo gradm2 gradm 2.1.14 grsecurity administration program Usage: gradm [option] ... Examples: gradm -P ...
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61 views

Is forcing an application to release some the allocated memory possible?

Ever since I came back to Firefox a year or so ago I have been facing the same issue over and over again - the browser just keeps eating up my memory. The problem arises from (maybe the incorrect ...
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53 views

Can I set a resource limit for the current process tree?

Let's say I'm running on a resource-constrained system, and I want to ensure that the applications I run open no more than 10 files total. If I try to do it using setrlimit, something like: if ...
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349 views

Find what process implements a FUSE filesystem

How can I get the process ID of the driver of a FUSE filesystem? For example, I currently have two SSHFS filesystems mounted on a Linux machine: $ grep sshfs /proc/mounts host:dir1 ...
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Alternative to iotop for non-root user without sudo privileges

I'm looking for an alternative to iotop. Here's my situation: I want to find out if a program is accessing the hard drive a lot while running. iotop requires root/sudo privileges. My account is on ...
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372 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 ...
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280 views

How to kill a process giving it a number of seconds before a doing the forced kill?

I do have the PID of the process to be killed but I do want to give it the chance to die peacefully, without doing a -9. Expected behaviour: check if PID is still running for up to ten seconds and do ...
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532 views

Set process exclusivity in Linux

I am trying to measure the performance of a process. I have widely ranging performance measurements on small bit of single-threaded deterministic code that should perform the same every time. I would ...
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682 views

How can I search/browse in some process's memory?

I'm using MacOS X 10.7 and I'm not very familiar with unix. Is there a command for a search in some process's memory for a string?
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File descriptor limits are lost after a system reboot

I'm trying to increase the default file descriptor limits for processes on my system. Specifically I'm trying to get the limits to apply to the Condor daemon and its sub-processes when the machine ...
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475 views

Show network connections of a process

There is a way to show the connections of a process? Something like that: show PID in which show is a command to do this, and PID is the pid of the process. The output that I want is composed by ...
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309 views

How to monitor top applications using CPU (and IO if possible) in a graph?

I need to find what and when these applications used so much CPU (and IO if possible too). This should be in a graphic timeline like we see in GNOME System Monitor CPU History. I also want to compare ...
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What is the need of the struct thread_info in locating struct task_struct?

While reading through the Linux Device Drivers, I could understand that the Process Descriptor (of type struct task_struct) has all the info regarding a particular task. The process descriptors are ...
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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 ...
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Slow down just one process to regulate CPU temperature

I have a program. When it is running, the CPU temperature raise from 50 to 80 Celcius, which is my major concern. I can control the CPU frequency to slow it down, but other processes will be slowed ...
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Keeping a process running on server even SSH is closed [duplicate]

I am running long program on server, which is basically Jar file of java program. I want to keep this program running even if SSH terminal is closed, how I can keep this program running on server?
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Why does a default Linux installation run more processes than a default OpenBSD installation?

If I ps -aux on Ubuntu (or any GNU/Linux distribution) without GUI I see ~100 processes running. If I ps -aux on OpenBSD without GUI, then I get ~10 processes. What is the explanation/reason for ...
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Please explain this output of ps -ef command?

A part of the output from the ps -ef command is given below : UID PID PPID C STIME TTY TIME CMD root 1 0 0 2012 ? 00:00:01 init [3] root 2 ...
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Why teamviewer starts again after being killed

My main desktop has Mint 14 and I approached it via SSH from another computer, because I didn't have a screen on the Mint one. Then I tried to start teamviewer just I order to launch its desktop ...
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Force change of a user's cwd as root

I'm looking to change a user's process such that I can set it's cwd. Related, and secondary to the question, I have a filesystem I want to unmount but a user is sitting on it with a bash process. I ...
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How do I get a mapping of Pid to Port?

I have a process which I need to run on a specific port. I have started some other process on that port and I need to kill it. Unfortunately, I don't remember the name/pid of the other process so I ...
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Run a process to particular/dedicated pid only

I have a c program executable or shell script which I want to run very often. If I want to stop/pause or to notify something I will send signal to that process. So every time I have to check the pid ...
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How to pkill by “command name”?

So I'm executing a command like: COMMANDNAME -PARAMETERS But..why can't I kill it with "pkill"? I'm trying with: pkill -9 "COMMANDNAME -PARAMETERS" but it doesn't kills the "COMMANDNAME ...
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621 views

why new pid is smaller than the old ones?

Is there any chance the new process's pid is smaller than the existed ones ? I have a daemon process which will restart when be killed, I recorded the pids, and found that the pid first came smaller, ...
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What call before a fork?

A long while ago I went to a job interview with a thoroughly weird company in London who claimed to be expert Unix consultants. Anyway these people were complete nutters and not surprisingly the ...
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How to kill stubborn process

I've an annoying process that won't die: ps -A | grep "nzbget" gives me: 11394 pts/3 00:00:00 nzbget If I try: pkill nzbget (or 11394) ...I get no response and the process is still alive, ...
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kill a group of processes with negative PID

kill -TERM -PID is supposed to kill PID and all its child processes. but this doesn't work on openSUSE, it always tell me that no such process -PID no matter what PID i use. So if the negative PID ...
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834 views

How do I execute a script later?

I need to compile gcc45 on my computer and that's a lengthy and resource-intensive process for my computer, so I'd prefer to have it do it while I sleep (at night). What's the closest thing to: $ ...
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Check for Process if Same is Running

Is there a script or a way in linux that when I try to execute a shell script/process, if the same is running, it will prompt that same is running and will exit otherwise it will continue.