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Diffstat (limited to 'manual/tunables.texi')
| -rw-r--r-- | manual/tunables.texi | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/manual/tunables.texi b/manual/tunables.texi index 3345a23969..09a25655ae 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -32,6 +32,7 @@ their own namespace. * Tunable names:: The structure of a tunable name * Memory Allocation Tunables:: Tunables in the memory allocation subsystem * Elision Tunables:: Tunables in elision subsystem +* POSIX Thread Tunables:: Tunables in the POSIX thread subsystem * Hardware Capability Tunables:: Tunables that modify the hardware capabilities seen by @theglibc{} @end menu @@ -281,6 +282,32 @@ of try lock attempts. The default value of this tunable is @samp{3}. @end deftp +@node POSIX Thread Tunables +@section POSIX Thread Tunables +@cindex pthread mutex tunables +@cindex thread mutex tunables +@cindex mutex tunables +@cindex tunables thread mutex + +@deftp {Tunable namespace} glibc.pthread +The behavior of POSIX threads can be tuned to gain performance improvements +according to specific hardware capabilities and workload characteristics by +setting the following tunables in the @code{pthread} namespace: +@end deftp + +@deftp Tunable glibc.pthread.mutex_spin_count +The @code{glibc.pthread.mutex_spin_count} tunable sets the maximum number of times +a thread should spin on the lock before calling into the kernel to block. +Adaptive spin is used for mutexes initialized with the +@code{PTHREAD_MUTEX_ADAPTIVE_NP} GNU extension. It affects both +@code{pthread_mutex_lock} and @code{pthread_mutex_timedlock}. + +The thread spins until either the maximum spin count is reached or the lock +is acquired. + +The default value of this tunable is @samp{100}. +@end deftp + @node Hardware Capability Tunables @section Hardware Capability Tunables @cindex hardware capability tunables |