Hi,
I wrote the following program to understand mutexes. If I run the program , number of threads is shown as zero, even after creating one thread. When running with gdb, it works fine.
The function process is used to update global variable (used to keep track of threads). It looks like the second instance of display (which displays number of threads ) is running before the counter gets incremented. If I add a pthread_join in main thread it works (main thread waits for created thread to complete). Is there a better way to address this and is my understanding correct? Thanks
Is it possible that the function "pthread_cond_broadcast" block itself and the function "pthread_cond_wait" unblock in multi-threads programming ? The operating system is AIX 5.2, its maintenance level is : 5.2.0.4, VisualAge C++ 6.0.
Thanks (0 Replies)
Running dedicated on AIX with 4 processors, creating 4 threads, each with equal work to do, only runs about 20% faster than 1 thread with all of the work. Test case has no blocking but does share memory for read access only.
Any ideas why I'm only seeing 20% gain? Is this typical on AIX? ... (1 Reply)
I have written a shell scritp in which i am using a variable which is declared before a while loop and i am updaitng the variable in while loop and want to use its updated value outside the loop. I am not able to do so, b'coz the scope of the variable is limited to the while loop only and when i am... (5 Replies)
Hello,
I run my pthread code on Linux with 4 processors. However, the speed up is only 2 times.
The code is about solving equation (G+s(i)C)z(i)=B*us(i), i=1,...,n. Here G,C are m*m matrix, B*us(i) is a m*1 vector and s(i) are n different numbers. I need to solve the equation n times to... (1 Reply)
Hi Guyz,
I have a requirement like, i have to run a script every hour to count the number of errors encountered.
At the end of the day, i need to send them the total number of errors, that have ocurred the entire day.
For eg. if 10 errors occurred for starting 1 hr, 5 for next 1 hr, so on.... (1 Reply)
Hello,
I have got some issue with the struct variable with passed arguments
the variable in the sturct is only recognize the last value their assigned to
I'm pretty confused why the mutex didn't work out
here is my program:
#include<stdio.h>
#include<pthread.h>
pthread_mutex_t lock... (3 Replies)
Hi All,
Im new to shell scripting. I am running EgA.sh and setting one global variable XYZ=0 . Also calling another EgB.sh from EgA.sh, changing the value of XYZ=10
but after executing EgB.sh, value of XYZ is still 0. Im expecting it to be 10.
Anyone for help. Thanks in Advance. :) (5 Replies)
Hi,
I have created a variable say today at the begin having 123 as its value and inside a for loop it gets resolved to some value say 150 in its first iteration.
How can I use this value 150 ( 1st iteration's ) outside the scope of for loop ?. In the same way I wanted to use all iteration's... (1 Reply)
Hi,
I am using Linux and sh shell
count=7
find * -prune -type d | sort -r -n | ( while read d; do
if ; then
echo "FOUND COUNTER1 is: $count"
break 2;
fi
done
echo "FOUND COUNTER2 is: $count" )
if ; then
echo "Problem: Multiple or NO records...Please CHECK !!"
fi
Output: ... (4 Replies)
Does anyone know why the below script is not working? Why is not the variable tot_files updated?
location=$1
cd "$location"
tot_files=0
(
echo ""
# recursively gets the total number of files
tot_files=$(for t in files ; do echo `find . -type ${t:0:1} | wc -l` $t | cut -f1... (12 Replies)
Discussion started by: soichiro
12 Replies
LEARN ABOUT DEBIAN
pi_stress
pi_stress(8) Linux System Administrator's Manual pi_stress(8)NAME
pi_stress - a stress test for POSIX Priority Inheritance mutexes
SYNOPSIS
pi_stress [-i|--inversions inversions] [-t|--duration seconds] [-g|--groups groups [-d|--debug] [-v|--verbose] [-s|--signal] [-r|--rr]
[-p|--prompt] [-m|--mlockall] [-u|--uniprocessor]
pi_stress -h|--help
DESCRIPTION
pi_stress is a program used to stress the priority-inheritance code paths for POSIX mutexes, in both the Linux kernel and the C library. It
runs as a realtime-priority task and launches inversion machine thread groups. Each inversion group causes a priorty inversion condition
that will deadlock if priority inheritance doesn't work.
OPTIONS -i n|--inversions=n
Run for n number of inversion conditions. This is the total number of inversions for all inversion groups. Default is -1 for infi-
nite.
-t n|--duration=n
Run the test for n seconds and then terminate.
-g n|--groups=n
The number of inversion groups to run. Defaults to 10.
-d|--debug
Run in debug mode; lots of extra prints
-v|--verbose
Run with verbose messages
-s|--signal
Terminate on receipt of SIGTERM (Ctrl-C). Default is to terminate on any keypress.
-r|--rr
Run inversion group threads as SCHED_RR (round-robin). The default is to run the inversion threads as SCHED_FIFO.
-p|--prompt
Prompt before actually starting the stress test
-u|--uniprocessor
Run all threads on one processor. The default is to run all inversion group threads on one processor and the admin threads (report-
ing thread, keyboard reader, etc.) on a different processor.
-m|--mlockall
Call mlockall to lock current and future memory allocations and prevent being paged out
-h|--help
Display a short help message and options.
CAVEATS
The pi_stress test threads run as SCHED_FIFO or SCHED_RR threads, which means that they can starve critical system threads. It is advisable
to change the scheduling policy of critical system threads to be SCHED_FIFO prior to running pi_stress and use a priority of 10 or higher,
to prevent those threads from being starved by the stress test.
BUGS
No documented bugs.
AUTHOR
Clark Williams <williams@redhat.com>
Nov 27, 2006 pi_stress(8)
03-20-2012
