title: System-Wide Futex Contention
name: futexes.stp
version: 1.0
author: anonymous
keywords: syscall locking futex
subsystem: locking
status: production
exit: user-controlled
output: sorted-list on-exit
scope: system-wide
description: The script watches the futex syscall on the system. On exit the futexes address, the number of contentions, and the average time for each contention on the futex are printed from lowest pid number to highest.
test_check: stap -p4 futexes.stp
test_installcheck: stap futexes.stp -c "sleep 0.2"