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| author | Paul Murphy <murphyp@linux.vnet.ibm.com> | 2015-09-03 13:40:21 -0500 |
|---|---|---|
| committer | Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com> | 2015-10-15 18:56:10 -0300 |
| commit | fadd2ad9cc36115440d50b0eae9299e65988917d (patch) | |
| tree | 98e5446434a66f7bd64cb1a0f31aac778ea31413 /sysdeps/unix/sysv/linux/powerpc/lowlevellock.h | |
| parent | e5e6bea22a2939fe7c415a375992f3ca19f9ff2e (diff) | |
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powerpc: Optimize lock elision for pthread_mutex_t
With TLE enabled, the adapt count variable update incurs
an 8% overhead before entering the critical section of an
elided mutex.
Instead, if it is done right after leaving the critical
section, this serialization can be avoided.
This alters the existing behavior of __lll_trylock_elision
as it will only decrement the adapt_count if it successfully
acquires the lock.
* sysdeps/unix/sysv/linux/powerpc/elision-lock.c
(__lll_lock_elision): Remove adapt_count decrement...
* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
(__lll_trylock_elision): Likewise.
* sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
(__lll_unlock_elision): ... to here. And utilize
new adapt_count parameter.
* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
(__lll_unlock_elision): Update to include adapt_count
parameter.
(lll_unlock_elision): Pass pointer to adapt_count
variable.
Diffstat (limited to 'sysdeps/unix/sysv/linux/powerpc/lowlevellock.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/powerpc/lowlevellock.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h b/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h index 16479e7753..6769c253ce 100644 --- a/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h @@ -32,7 +32,7 @@ extern int __lll_timedlock_elision extern int __lll_lock_elision (int *futex, short *adapt_count, int private) attribute_hidden; -extern int __lll_unlock_elision(int *lock, int private) +extern int __lll_unlock_elision (int *lock, short *adapt_count, int private) attribute_hidden; extern int __lll_trylock_elision(int *lock, short *adapt_count) @@ -41,7 +41,7 @@ extern int __lll_trylock_elision(int *lock, short *adapt_count) #define lll_lock_elision(futex, adapt_count, private) \ __lll_lock_elision (&(futex), &(adapt_count), private) #define lll_unlock_elision(futex, adapt_count, private) \ - __lll_unlock_elision (&(futex), private) + __lll_unlock_elision (&(futex), &(adapt_count), private) #define lll_trylock_elision(futex, adapt_count) \ __lll_trylock_elision (&(futex), &(adapt_count)) |