git: 36a037f1501e - stable/13 - libthr: Patch to reduce latency to acquire+release a pthread mutex.

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Fri, 14 Jul 2023 04:13:08 UTC
The branch stable/13 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=36a037f1501e0969b56f643c5e9782334bd540e3

commit 36a037f1501e0969b56f643c5e9782334bd540e3
Author:     Greg Becker <becker.greg@att.net>
AuthorDate: 2023-07-07 22:03:14 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2023-07-13 01:29:17 +0000

    libthr: Patch to reduce latency to acquire+release a pthread mutex.
    
    (cherry picked from commit b370ef156ab9d88450e9bc0440df522aec88cc44)
---
 lib/libthr/thread/thr_mutex.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 2cbfd9a459d3..40e0b7382f95 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -596,7 +596,7 @@ check_and_init_mutex(pthread_mutex_t *mutex, struct pthread_mutex **m)
 
 	*m = *mutex;
 	ret = 0;
-	if (*m == THR_PSHARED_PTR) {
+	if (__predict_false(*m == THR_PSHARED_PTR)) {
 		*m = __thr_pshared_offpage(mutex, 0);
 		if (*m == NULL)
 			ret = EINVAL;
@@ -714,7 +714,7 @@ done:
 	return (ret);
 }
 
-static inline int
+static __always_inline int
 mutex_lock_common(struct pthread_mutex *m, const struct timespec *abstime,
     bool cvattach, bool rb_onlist)
 {
@@ -728,7 +728,7 @@ mutex_lock_common(struct pthread_mutex *m, const struct timespec *abstime,
 	if (!rb_onlist)
 		robust = _mutex_enter_robust(curthread, m);
 	ret = _thr_umutex_trylock2(&m->m_lock, TID(curthread));
-	if (ret == 0 || ret == EOWNERDEAD) {
+	if (__predict_true(ret == 0) || ret == EOWNERDEAD) {
 		enqueue_mutex(curthread, m, ret);
 		if (ret == EOWNERDEAD)
 			m->m_lock.m_flags |= UMUTEX_NONCONSISTENT;
@@ -951,7 +951,7 @@ mutex_self_lock(struct pthread_mutex *m, const struct timespec *abstime)
 	return (ret);
 }
 
-static int
+static __always_inline int
 mutex_unlock_common(struct pthread_mutex *m, bool cv, int *mtx_defer)
 {
 	struct pthread *curthread;