You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
67 lines
2.2 KiB
67 lines
2.2 KiB
2 years ago
|
commit 6bcfbee7277e4faa4b693bd965931f0d1883005d
|
||
|
|
Author: H.J. Lu <hjl.tools@gmail.com>
|
||
|
|
Date: Fri Nov 12 11:47:42 2021 -0800
|
||
|
|
|
||
|
|
Move assignment out of the CAS condition
|
||
|
|
|
||
|
|
Update
|
||
|
|
|
||
|
|
commit 49302b8fdf9103b6fc0a398678668a22fa19574c
|
||
|
|
Author: H.J. Lu <hjl.tools@gmail.com>
|
||
|
|
Date: Thu Nov 11 06:54:01 2021 -0800
|
||
|
|
|
||
|
|
Avoid extra load with CAS in __pthread_mutex_clocklock_common [BZ #28537]
|
||
|
|
|
||
|
|
Replace boolean CAS with value CAS to avoid the extra load.
|
||
|
|
|
||
|
|
and
|
||
|
|
|
||
|
|
commit 0b82747dc48d5bf0871bdc6da8cb6eec1256355f
|
||
|
|
Author: H.J. Lu <hjl.tools@gmail.com>
|
||
|
|
Date: Thu Nov 11 06:31:51 2021 -0800
|
||
|
|
|
||
|
|
Avoid extra load with CAS in __pthread_mutex_lock_full [BZ #28537]
|
||
|
|
|
||
|
|
Replace boolean CAS with value CAS to avoid the extra load.
|
||
|
|
|
||
|
|
by moving assignment out of the CAS condition.
|
||
|
|
|
||
|
|
(cherry picked from commit 120ac6d238825452e8024e2f627da33b2508dfd3)
|
||
|
|
|
||
|
|
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
|
||
|
|
index 9f40928cc6b9a067..49901ffa0a96d659 100644
|
||
|
|
--- a/nptl/pthread_mutex_lock.c
|
||
|
|
+++ b/nptl/pthread_mutex_lock.c
|
||
|
|
@@ -305,10 +305,9 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
|
||
|
|
meantime. */
|
||
|
|
if ((oldval & FUTEX_WAITERS) == 0)
|
||
|
|
{
|
||
|
|
- int val;
|
||
|
|
- if ((val = atomic_compare_and_exchange_val_acq
|
||
|
|
- (&mutex->__data.__lock, oldval | FUTEX_WAITERS,
|
||
|
|
- oldval)) != oldval)
|
||
|
|
+ int val = atomic_compare_and_exchange_val_acq
|
||
|
|
+ (&mutex->__data.__lock, oldval | FUTEX_WAITERS, oldval);
|
||
|
|
+ if (val != oldval)
|
||
|
|
{
|
||
|
|
oldval = val;
|
||
|
|
continue;
|
||
|
|
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
|
||
|
|
index 90cede9446e33fcf..2e5506db06ccb1ec 100644
|
||
|
|
--- a/nptl/pthread_mutex_timedlock.c
|
||
|
|
+++ b/nptl/pthread_mutex_timedlock.c
|
||
|
|
@@ -234,10 +234,9 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
|
||
|
|
meantime. */
|
||
|
|
if ((oldval & FUTEX_WAITERS) == 0)
|
||
|
|
{
|
||
|
|
- int val;
|
||
|
|
- if ((val = atomic_compare_and_exchange_val_acq
|
||
|
|
- (&mutex->__data.__lock, oldval | FUTEX_WAITERS,
|
||
|
|
- oldval)) != oldval)
|
||
|
|
+ int val = atomic_compare_and_exchange_val_acq
|
||
|
|
+ (&mutex->__data.__lock, oldval | FUTEX_WAITERS, oldval);
|
||
|
|
+ if (val != oldval)
|
||
|
|
{
|
||
|
|
oldval = val;
|
||
|
|
continue;
|