title: System-Wide Shared Futex Contention
name: futexes2.stp
version: 1.0
author: jistone
keywords: syscall locking futex
subsystem: locking
status: production
exit: user-controlled
output: sorted-list on-exit
scope: system-wide
description: The script watches just shared futex syscalls on the system. On exit the futex's key, the number of contentions, and the average time for each contention on the futex are printed from lowest pid number to highest.
test_support: stap -l 'kernel.function("futex_wait_setup")'
test_check: stap -p4 futexes2.stp
test_installcheck: stap futexes2.stp -T 1