script examples identifying contended user-space locks (i.e. futex contentions) examples of SystemTap scripts identifying contended user-space locks (i.e. futex contentions) identifying contended user-space locks (i.e. futex contentions) examples of SystemTap scripts contended user-space locks (futex contentions), identifying examples of SystemTap scripts WAR STORY: Futex contention http://sourceware.org/systemtap/wiki/WSFutexContention?highlight=((WarStories)) no script in examples This section describes how to identify contended user-space locks throughout the system within a specific time period. The ability to identify contended user-space locks can help you investigate hangs that you suspect may be caused by futex contentions. futex contentions, identifying examples of SystemTap scripts futex contention, definition examples of SystemTap scripts script examples process deadlocks (arising from futex contentions) examples of SystemTap scripts process deadlocks (arising from futex contentions) process deadlocks (arising from futex contentions) examples of SystemTap scripts Simply put, a futex contention occurs when multiple processes are trying to access the same region of memory. In some cases, this can result in a deadlock between the processes in contention, thereby appearing as an application hang. script examples futex system call examples of SystemTap scripts futex system call futex system call examples of SystemTap scripts To do this, probes the futex system call. needs to be manually stopped; upon exit, it prints the following information: Name and ID of the process responsible for a contention The region of memory it contested How many times the region of memory was contended Average time of contention throughout the probe contains an excerpt from the output of upon exiting the script (after approximately 20 seconds). [...] automount[2825] lock 0x00bc7784 contended 18 times, 999931 avg us synergyc[3686] lock 0x0861e96c contended 192 times, 101991 avg us synergyc[3758] lock 0x08d98744 contended 192 times, 101990 avg us synergyc[3938] lock 0x0982a8b4 contended 192 times, 101997 avg us [...]