Tagged Questions
0
votes
1answer
28 views
Identify Tasks/Process which are 7 days old in linux
How can I identify the processes running since 7 days in Linux?
4
votes
3answers
51 views
Dynamic file content generation: Satisfying a 'file open' by a 'process execution'
I have a read-only file, F.
A program, P, that I'm not the author of, needs to read F.
I want the content of F to come from another 'generator' program, G, whenever P tries to read F (taking F to ...
4
votes
3answers
66 views
Can I pipe any two processes to each other?
In this page from The Design and Implementation of the 4.4BSD Operating System, it is said that:
A major difference between pipes and sockets is that pipes require a
common parent process to set ...
0
votes
0answers
29 views
dynamic pool of process C [migrated]
I'm writing program in UNIX on C. I have to write client-server(TCP) program on sockets. Client sends some information and server answer. No matter what client sends or receives because I successfully ...
4
votes
5answers
101 views
Is a persistent zombie process sign of a bug?
(OS: Debian variant.)
Having a process with zombie-status. The PPid belonged to a gvim process.
The contents of /proc/[pid]/wchan is do_exit,
/comm is sh and /cmdline is empty, /status is shown ...
1
vote
1answer
59 views
Do kernel counters for jiffies in state exist in Linux?
I am looking to get time/jiffie stats on the state of a daemon process. The states I'm referring to are mentioned in the Linux Kernel Proc Filesystem document. Running, Sleeping, uninterruptible ...
1
vote
1answer
33 views
Looking for /procfs documentation, describing values and units of measurement
Surprisingly, comprehensive documentation for /procfs is hard to find.
For my specific question, I am looking at: cat /proc/1/statm (let's use pid=1 because it seems to be always there). I just ran ...
1
vote
2answers
63 views
How to decrease ps aux output to a few lines?
When my computer is slowing down, I usually run ps aux --sort -rss to find out which process consumes too much memory. There may be a lot of processes. How to see only a few ones?
0
votes
4answers
121 views
Show running processes with file name(s)?
I am using putty to connect my linux server which my sites are in. I can run
# ps aux | less
to show running processes. But I want to display which files running these processes ?
I have also ...
2
votes
2answers
99 views
Where is the virtual memory stored on hard drive?
If a process wants to access a memory address that is not in physical memory, the OS outsources a page frame from physical memory to the hard drive for later use. Where on the hard drive is this data ...
1
vote
3answers
129 views
Block network access of a process?
Is it possible to block the (outgoing) network access of a single process?
2
votes
1answer
235 views
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 ...
1
vote
2answers
179 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 ...
2
votes
3answers
141 views
Why does Firefox refuse to die despite killing it with pkill -9?
I am issuing the following command to kill Firefox on my Red Hat Linux box:
[subhrcho@slc04lyo ~]$ pkill -9 -f firefox
[subhrcho@slc04lyo ~]$
However, when I try to invoke Firefox through ...
0
votes
2answers
65 views
Which process updates /proc/scsi/scsi?
I wrote C that displays info about my hardware on ubuntu. Now I wonder how I can make it more flexible such as querying the hardware directly instead of the file the os updates. So I think I can look ...
3
votes
2answers
266 views
Bash script wait for processes and get return code
I am trying to create a script which will start many background command.
For each background command I need to get the return code.
I have been trying the following script :
#!/bin/bash
set -x
...
3
votes
3answers
268 views
How to track the number of processes and forks per user?
I need to figure out how many forks are done and how many concurrent processes are run by each user over time. It does not look like this information is tracked by my distribution.
I know how to ...
5
votes
1answer
125 views
Real time priorities in non real time OS
If I do the following command on my standard Linux Mint installation:
comp ~ $ ps -eo rtprio,nice,cmd
RTPRIO NI CMD
...
99 - [migration/0]
99 - [watchdog/0]
99 - [migration/1]
- 0 ...
3
votes
1answer
106 views
What is “automatic stack expansion”?
getrlimit(2) has the following definition
in the man pages:
RLIMIT_AS
The maximum size of the process's virtual memory (address space) in bytes. This limit affects calls to brk(2), mmap(2) and ...
12
votes
2answers
270 views
When was a process started
To know when was a process started, my first guess was to check the time when /proc/<pid>/cmdline was written/modified the last time.
ps also shows a START field. I thought both of these ...
0
votes
0answers
26 views
How can I see a process' thread count? [duplicate]
Possible Duplicate:
Is there a way to see details of all the threads that a process has in Linux?
I want to see the thread count which belongs to a process in linux. What command should I ...
1
vote
2answers
202 views
Discrepancy between reported used memory and sum of application memory usage
I'm running a desktop system that quite regularly suffers from lack of memory, this prompted me to investigate what causes the issue in the first place.
Problem is, there's no single process that ...
1
vote
2answers
102 views
How to view commandline of processes executed in last 10 seconds
Is there a view to log and list down the processes executed in last 10 seconds ?
I especially want to trace the command line.
3
votes
1answer
181 views
Cannot kill a java process
I have a java process that cannot be killed. I have tried every method I know, or that I have found on the internet to no avail. I have tried:
killall java
kill -9 <pid>
kill -11 <pid>
...
0
votes
1answer
442 views
ATOP shows red line vmcom and vmlim. What does it mean?
utility atop shows:
ATOP - MyServer 2013/01/07 00:03:57 10 seconds elapsed
PRC | sys 2.18s | user 8.33s | #proc 141 | #zombie 0 | #exit 0 |
CPU | sys 21% | ...
1
vote
3answers
137 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 ...
3
votes
1answer
128 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 ...
1
vote
2answers
143 views
How to run linux process and come back to it later?
I'm trying to run a minecraft server on linux. Running the server starts an important interactive session. I can run the server in the background by appending & at the end of the command and log ...
2
votes
3answers
253 views
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 ...
1
vote
1answer
69 views
Is there any way to attach latrace to an already-running process?
I want to trace a running multi-threaded process's library calls. As of 5 November 2012, there's only one way to get ltrace to fully support tracing multi-threaded processes: you must check out and ...
3
votes
1answer
367 views
When do jiffies increment? How a process runs in a jiffy?
I know that jiffies length is selected at kernel compile time and it is defaulted to 250 (4ms). Source: man 7 time - The Software Clock, HZ, and Jiffies
I wonder what happens inside a jiffy. What are ...
2
votes
4answers
130 views
How to find out what is this process for?
I have this 'java' process running for 3 hours ( I guess ). I didn't see it before and I wonder how could I find out where it's coming from?
Here is a screenshot:
EDIT: ok I figured it out, it's ...
0
votes
1answer
319 views
What is the advantage of using pthreads in Linux?
I read somewhere that Linux threads are really implemented as processes in the kernel since with today's hardware and on the Linux platform, the thread model is inefficient compared to the process ...
0
votes
1answer
181 views
Where can I see the processes running at startup?
I'm using backtrack5 R2 and sometimes when I log in the information showed says that There is 1 zombie process, where can I see what process is running?
3
votes
1answer
532 views
Find processes using a network interface
I'm trying to find a way to safely shutdown a network interface, i.e. without disturbing any processes. For this I need to find out what processes are currently using that interface. Tools like ss, ...
0
votes
0answers
107 views
Unable to use SIP over VPN, how to find out why
I am doing a VPN access using openvpn utility to connect to my private network. However I cannot use my SIP soft-phone service (which uses a private domain) even if I am connected to that private ...
1
vote
1answer
224 views
What process created this window with no PID associated? [duplicate]
Possible Duplicate:
What process created this X11 window?
I need to kill a process that spawned a window which seems to have no PID associated with it. At least that is what xdotool says:
...
2
votes
2answers
90 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 ...
2
votes
0answers
94 views
How to find current chroot jail path on Linux <2.6.26
While running kernel 2.6.26 or newer it's possible to get the path of the current chroot jail by comparing the mountinfo of the current process and the init process. Is there a way to get the same ...
3
votes
1answer
960 views
mmap() failed: Cannot allocate memory - how do I find out who's complaining?
mmap() failed is popping up in my .xsession-errors in bursts. But there's no indication about what application it is failing with. How do I look into this after it has happened? I usually discover the ...
9
votes
3answers
228 views
Where to find explanation of kernel processes?
I want to know about kernel processes, like [migration], [kswapd], etc. Where are kernel processes like these documented?
4
votes
1answer
658 views
Detailed Per-Process Profiling
I am looking for a way to profile a single process including time spent for CPU, I/O, memory usage over time and optionally system calls.
I already know callgrind offering some basic profiling ...
4
votes
1answer
487 views
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 ...
3
votes
1answer
253 views
Rationale for making user space text segment start at 0x8048000
I read somewhere that (at least since Linux v. 2.6) all user-space code is placed at load address 0x8048000 in the virtual memory address space.
My own observations confirm this. I have done a
cat ...
4
votes
2answers
490 views
Linux running slow with 0 swap left
Our Linux server is responding very slowly. top doesn't show any excessive CPU usage. I noticed that even though there's about 5GB of free memory, the system is using all of swap with no free swap ...
3
votes
2answers
464 views
How can I kill the top CPU/IO process quickly?
I find that sometimes my Linux will stop responding, so I need to switch to another terminal with CtrlAltF2, and type a command to kill the top CPU usage process or top IO usage process, so that the ...
3
votes
1answer
1k views
How to see how many context switches a process makes?
I want to see if my process makes a lot of context switches. I also want to see how manpulating task groups affects the number of context switches.
1
vote
2answers
359 views
Kill all processes related to an application
I have two processes that are temporarily spawned and I need to kill them. Here are the processes from ps aux
david 38329 0.0 5.0 3916476 104624 s002 S 11:33AM 0:17.43 ...
1
vote
1answer
323 views
How to preload my .so everytime an application executes?
I've successfully used a hook under linux with this article: http://hackerboss.com/overriding-system-functions-for-fun-and-profit/
Now I want to make my .so file load every time espeak loads up. No ...
4
votes
1answer
712 views
Nice and child processes
Can someone tell me what the relationship between a specified nice level and child processes ?
for example, if I have a default nice of 0, and i start a script with nice 5, which in turn starts some ...
