close_wake_blkdflks(5)close_wake_blkdflks(5)NAMEclose_wake_blkdflks - Wakeup the threads blocked for file segment lock
upon file close.
unless a multithreaded application requires close(2), not to wait on
threads blocked for file segment lock.
In a multithreaded application with file segment locking, a thread
calling close(2) might get blocked for some time or indefinitely. This
is because, close(2) waits for the threads that are blocked to acquire
the file segment lock to return to the application from the correspond‐
ing file segment locking system call such as lockf(2) or fcntl(2).
is a static tunable that enables or disables support for the threads
calling close(2) to wakeup the other threads of the same process, which
are sleeping on to acquire a file segment lock in a multithreaded
Who Is Expected to Change This Tunable?
System administrators who require close(2) thread not to get blocked on
the other threads sleeping on to acquire a file segment lock in a mul‐
Restrictions on Changing
Changes to this tunable only take effect after a reboot of the system.
When Should the Tunable Be Turned On?
The value of should be set to if multithread applications require their
close(2) thread not to get blocked indefinitely on the other threads
waiting to acquire a file segment lock. Changes are system-wide.
What Are the Side Effects of Turning the Tunable On?
In a multi threaded application, close(2) might take few more cycles to
complete based on the number of threads in the process.
When Should the Tunable Be Turned Off?
The value of may be set to if there are no multithreaded applications
that might make the close(2) thread to get blocked on other threads
waiting to acquire a file segment lock using fcntl(2) or lockf(2).
What Are the Side Effects of Turning the Tunable Off?
In a multithread application involving file segment locking, close(2)
thread may hang indefinitely.
What Other Tunable Values Should Be Changed at the Same Time?
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
Installation of optional kernel software, from HP or other vendors, may
cause changes to tunable parameter values. After installation, some
tunable parameters may no longer be at the default or recommended val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
was developed by HP.
SEE ALSOclose(2), fcntl(2), lockf(2).
Tunable Kernel Parameters close_wake_blkdflks(5)