|
|
|
|
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)
