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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 /ChangeLog | |
| 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 'ChangeLog')
| -rw-r--r-- | ChangeLog | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -1,5 +1,20 @@ 2015-10-15 Paul E. Murphy <murphyp@linux.vnet.ibm.com> + * 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. + +2015-10-15 Paul E. Murphy <murphyp@linux.vnet.ibm.com> + * nptl/pthread_mutex_unlock.c (lll_unlock_elision): Add elision adapt_count parameter to list of arguments. * sysdeps/unix/sysv/linux/powerpc/lowlevellock.h |