0
votes
0answers
21 views

Where does the process go after changing to state TASK_STOPPED in Linux? [closed]

Supposed that we have a runnning process in Linux system, the state of that process will be TASK_RUNNING, after that if It receive the SIGSTOP signal , the process's state will change to TASK_STOPPED. ...
11
votes
2answers
858 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 ...
4
votes
1answer
146 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 ...
0
votes
2answers
184 views

Calculating CPU time of process in RHEL 5.3

For a process management,I would need to remove a process that exceeds a certain amount of CPU time, for example 1 hour.In PS command ,it has TIME parameter shows the total CPU time of a process .So ...
2
votes
1answer
96 views

Process overwrite access restriction

I want to run a program so that it can only create new files and not overwrite existing ones. Does something like this exist? $ fsaccess --can read,write --not overwrite --command bash -c 'echo ...
5
votes
3answers
558 views

Using `kill -s 0 $pid` vs `[[ -e /proc/$pid ]]` to detect if PID is running

One of the idioms often used to check if process is running is to use kill -s 0 $pid. My question is, does it have any upsides over using [[ -e /proc/$pid ]] construct? The script I'm writing is ...
1
vote
2answers
59 views

What information about a process is retrievable after it is terminated? [duplicate]

After a process has been terminated, is it possible to retrieve any information about it, such as when it started and finished, &c. Is it possible to enable logging of this information?
3
votes
3answers
83 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 ...
8
votes
3answers
2k views

What's the difference between pkill and killall?

I know that pkill has more filtering rules than killall. My question is, what is the difference between: pkill [signal] name and killall [signal] name I've read that killall is more effective ...
16
votes
4answers
2k views

What happens if you edit a script during execution?

I have a general question, which might be a result of misunderstanding of how processes are handled in Linux. For my purposes I am going to define a 'script' as a snippet of bash code saved to a text ...
1
vote
2answers
1k views

multiple background processes in a script

Suppose if i have a situation in which some files need to be copied and it takes long time so i would have to go for parallel processing of the file copy. for example it may look like this for i in ...
1
vote
3answers
706 views

Killing all the process of a command except first process

I am sometimes stuck in a situation where a script/command kept in Cron runs more than once because of some reasons (the first instance is not completed fully, the second instance of the same process ...
2
votes
2answers
513 views

Putting Linux processes on certain CPU cores [duplicate]

Possible Duplicate: How can I set the processor affinity of a process on Linux? Computer CPUs have many cores insde them nowadays. I have always wondered if there is a way to, when I start ...
2
votes
2answers
138 views

How to constrain the resources an application can use on a linux web server

This is the situation: I have a PHP/MySQL web application that does some PDF processing and thumbnail creation. This is done by using some 3rd party command line software on the server. Both kinds of ...
5
votes
2answers
454 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 ...
2
votes
0answers
144 views

Need good ideas about improving any Linux service [closed]

I have a project assigned to me by OS teacher to choose any Linux service and improve it. Currently I am totally blank in this. I am not sure which service should I use which can easily be implemented ...
2
votes
1answer
569 views

How can I manage jobs after I disconnect from my tty/ssh session?

If I ssh to a box and start a task that will take some time to complete I usually press control+z to pause the process, and then immediately type bg 1 to put run it in the background. I can then type ...
5
votes
3answers
5k views

What is a command to find priority of process in Linux?

How can i view the priority of a specific process ?
0
votes
1answer
3k views

How to know how long a process has been running? [duplicate]

Possible Duplicate: How to check how a long a program has been running? I am interested in doing this purely using bash.
12
votes
6answers
8k 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.
222
votes
9answers
99k 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 ...