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0
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1answer
19 views

won't the ever changing affinity assigned to threads by the Linux kernel have adverse effect on overall performance?

In my program, I have several threads that are started with the process and that remain until the program ends. They will meet different loads during the lifetime of the app, and at times they will ...
0
votes
0answers
21 views

Is it possible to name a QThread? [migrated]

I have a Linux Qt application that creates some QThreads. I know that when you create a thread it inherits the parent name and I can see it when I use htop or ps ax -L. Is it possible to name those ...
4
votes
3answers
345 views

How to call a service URL from bash shell script in parallel?

I have a service which I am calling from another application. Below is my service URL which I am calling - http://www.betaservice.domain.host.com/web/hasChanged?ver=0 I need to do some load test ...
5
votes
1answer
648 views

Multi-Threading/Forking in a bash script

I have written a bash script which is in following format: #!/bin/bash start=$(date +%s) inFile="input.txt" outFile="output.csv" rm -f $inFile $outFile while read line do -- Block of Commands ...
2
votes
3answers
86 views

Linux - preventing an application from failing due to lack of disk space

Due to an unpredicted scenario I am currently in need of finding a solution to the fact that an application (which I do not wish to kill) is slowly hogging the entire disk space. To give more context ...
1
vote
1answer
99 views

How to copy in two folders simultaneously using GNU parallel by spawning multiple threads?

I am trying to copy files from machineB and machineC into machineA as I am running my below shell script on machineA. If the files is not there in machineB then it should be there in machineC for ...
3
votes
1answer
58 views

Is each process considered a thread?

Is a Linux process considered a thread? For example, if I write a simple c program that calls pthread_create to create a new thread in main(), does that mean that I now have 2 threads, one for ...
0
votes
0answers
21 views

Problem with installing mcsima+

I am trying to install mcsima+, but I am facing an issue over step 5 which requires me to compile the program. The instruction I ran for step 5 is, 5. Compile a test program 'stream' - cd ...
2
votes
3answers
2k views

How to launch two threads in bash shell script?

I am trying to copy files from machineB and machineC into machineA as I am running my below shell script on machineA. If the files is not there in machineB then it should be there in machineC for ...
1
vote
1answer
2k views

Default stack size for pthreads

As I understand the default stack size for a pthread on linux is 16K. I am getting strange sesults on my 64bit ubuntu install. $ ulimit -s 8192 Also pthread_attr_init(&attr); ...
1
vote
2answers
197 views

How to copy three files at once instead of one file at a time in bash shell scripting?

I am running my shell script on machineA which copies the files from machineB and machineC to machineA. If the file is not there in machineB, then it should be there in machineC for sure. So I will ...
2
votes
1answer
86 views

Multiplex bash function execution

I created a bash function to "automagically" connect on our switches and retrive their startup-config using the expect command. I have to use expect because this switch does not accept the ssh ...
0
votes
2answers
148 views

Make Ubuntu acknowledge that a custom built version of PHP is installed

I'm trying to install PHP from source code on my Ubuntu 12.04 VPS. I'm installing PHP like this: Download the latest version from the php.net website. Configure it using the parameters below. ...
1
vote
0answers
242 views

What exactly is the lwp and threads in solaris?

The book "Solaris Internals" says Solaris executes kernel threads for kernel-related tasks, such as interrupt handling, memory page management, device drivers, etc. For user-process execution, kernel ...
2
votes
1answer
469 views

Running a process multiple times at the same time

I have a c++ program with opencv library which takes an image as input and perform pose estimation,color detection,phog. When I run this program from the command line it takes around 4-5sec to ...
4
votes
3answers
1k views

Why do top and ps show different PIDs for the same processes?

When I run top -H, I see that my multiple mysql threads all have the same PID. However, in ps -eLf I see each one has a different PID: ps -eLf UID PID PPID LWP C NLWP STIME TTY ...
2
votes
1answer
157 views

Which system calls could create a new process?

When executing ps command in my Linux system i see some user processes twice (different PID...). I wonder if they are new processes or threads of the same process. I know some functions in standard C ...
3
votes
1answer
431 views

Speed up zgrep on a multi-core computer

I'm running zgrep on a computer with 16 CPUs, but it only takes one CPU to run the task. Can I speed it up, perhaps utilize all 16 cores? P.S The IO is just fine, I could just copy the gzipped file ...
1
vote
3answers
216 views

can the “cat” command use multi-processes

I need to merge bunch of files in a directory on a unix box that has 8 cores. I am looking for a fast way to merge these files. The cat command uses only one core... is there a way where I can make it ...
15
votes
6answers
3k views

Why using more threads makes it slower than using less threads

Tried to run program X using 8 threads and it was over in n minutes. Tried to run same program using 50 threads and it was over in n*10 minutes. Why does this happen and how can I get optimal ...
1
vote
2answers
196 views

Is any part of the X.org software multithreaded?

None of the command-line shells that I am aware of are multithreaded. In particular, even those shells that support "job control" (Control-Z, bg, fg, etc) do so via facilities (namely, fork, exec, ...
0
votes
1answer
90 views

When was the threading implemented in unix?

Which is the first Unix version or Linux version which implemented threads. And in which version bound and unbound threads were implemented? I know that in current Linux version threads are unbound by ...
1
vote
0answers
82 views

multithread handling in AM1808 using embedded Linux

I am using AM1808 ARM9 based board using GCC compiler (UBUNTU 10.04) . I am using Sqlite3 database management. I have some requirement regarding handling threads in background having access on ...
2
votes
0answers
147 views

So the design of client-server separation is not the bottleneck of X Window?

In the answer of this, it mentioned: People also hear that X uses the "network" and think this is going to be a performance bottleneck. "Network" here means local UNIX domain socket, which has ...
1
vote
1answer
2k views

System sending SIGTERM and SIGKILL during normal work

I have a program (C++) that works with TCP sockets in multithreaded manner. The multithreading is intensive, about 100 threads (POSIX threads). Sometimes, not quite sure when, the program gets ...
2
votes
1answer
243 views

What makes the Linux scheduler seem unpredictable?

The question refers to the output of a multi-threaded application, where each thread merely prints its ID (user assigned number) on the standard output. Here all threads have equal priority and ...
-3
votes
2answers
88 views

Which Linux distro/mode offers lowest interference when running your own applications?

I'm interested in a Linux distro to build C projects and test their behavior in a very predictable and controlled environment. I'm especially concerned about letting the scheduler deal as much as ...
2
votes
1answer
603 views

Does uClibc support using pthreads?

I recently attended an embedded Linux course that stated that uClibc does not support the use of pthreads and that it only supports linuxthreads. Furthermore, the course instructor implied that ...
3
votes
2answers
804 views

What is meant by stack in connection to a process?

From the book Advanced programming in the Unix environment I read the following line regarding threads in Unix like systems All the threads within a process share the same address space, file ...
4
votes
2answers
7k views

Linux max threads count

my server has been running with Amazon Ec2 linux. I have a mongodb server inside. The mongodb server has been running under heavily load, and, unhappily , I've ran into a problem with it :/ As known, ...
1
vote
1answer
297 views

Analyzing the behavior of a threaded program

Is there an application that will do what Threadscope or the parallel tools of Visual Studio does for multithreaded program analysis in Linux?
5
votes
2answers
689 views

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 ...
3
votes
3answers
918 views

Is crontab multithread?

I don't know where I can find more information about crontab, so I ask here. Crontab is it multithread? How does it work?