git: 83d13d836b32 - main - locks: run the extra NULL check only with INVARIANTS

From: Gleb Smirnoff <glebius_at_FreeBSD.org>
Date: Sun, 30 Mar 2025 04:01:29 UTC
The branch main has been updated by glebius:

URL: https://cgit.FreeBSD.org/src/commit/?id=83d13d836b32af86bba62ddf86c2ef78389d13fd

commit 83d13d836b32af86bba62ddf86c2ef78389d13fd
Author:     Gleb Smirnoff <glebius@FreeBSD.org>
AuthorDate: 2025-03-30 03:55:31 +0000
Commit:     Gleb Smirnoff <glebius@FreeBSD.org>
CommitDate: 2025-03-30 03:56:05 +0000

    locks: run the extra NULL check only with INVARIANTS
    
    This reverts commit 73da0265c29c79641dab3e6b98452bd5afca01fb.
    This reverts commit 87ee63bac69dc49291f55590b8baa57cad6c7d85.
    
    Discussed with:         mjg
---
 sys/kern/kern_mutex.c  |  4 +---
 sys/kern/kern_rwlock.c | 16 ++++------------
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index d52f7e1eebd1..f952b3fc8805 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -1073,9 +1073,7 @@ __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v)
 	turnstile_chain_lock(&m->lock_object);
 	_mtx_release_lock_quick(m);
 	ts = turnstile_lookup(&m->lock_object);
-	if (__predict_false(ts == NULL)) {
-		panic("got NULL turnstile on mutex %p v %p", m, (void *)v);
-	}
+	MPASS(ts != NULL);
 	if (LOCK_LOG_TEST(&m->lock_object, opts))
 		CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m);
 	turnstile_broadcast(ts, TS_EXCLUSIVE_QUEUE);
diff --git a/sys/kern/kern_rwlock.c b/sys/kern/kern_rwlock.c
index ed6ca75bc7a5..e182d1fe9baf 100644
--- a/sys/kern/kern_rwlock.c
+++ b/sys/kern/kern_rwlock.c
@@ -784,12 +784,11 @@ __rw_runlock_hard(struct rwlock *rw, struct thread *td, uintptr_t v
     LOCK_FILE_LINE_ARG_DEF)
 {
 	struct turnstile *ts;
-	uintptr_t setv, passedv, queue;
+	uintptr_t setv, queue;
 
 	if (SCHEDULER_STOPPED())
 		return;
 
-	passedv = v;
 	if (__rw_runlock_try(rw, td, &v))
 		goto out_lockstat;
 
@@ -842,10 +841,7 @@ __rw_runlock_hard(struct rwlock *rw, struct thread *td, uintptr_t v
 		 * release the lock.
 		 */
 		ts = turnstile_lookup(&rw->lock_object);
-		if (__predict_false(ts == NULL)) {
-			panic("got NULL turnstile on rwlock %p passedv %p v %p",
-			    rw, (void *)passedv, (void *)v);
-		}
+		MPASS(ts != NULL);
 		turnstile_broadcast(ts, queue);
 		turnstile_unpend(ts);
 		td->td_rw_rlocks--;
@@ -1223,7 +1219,7 @@ __rw_wunlock_hard(volatile uintptr_t *c, uintptr_t v LOCK_FILE_LINE_ARG_DEF)
 {
 	struct rwlock *rw;
 	struct turnstile *ts;
-	uintptr_t tid, setv, passedv;
+	uintptr_t tid, setv;
 	int queue;
 
 	tid = (uintptr_t)curthread;
@@ -1271,7 +1267,6 @@ __rw_wunlock_hard(volatile uintptr_t *c, uintptr_t v LOCK_FILE_LINE_ARG_DEF)
 	 * of waiters or doing some complicated lock handoff gymnastics.
 	 */
 	setv = RW_UNLOCKED;
-	passedv = v;
 	v = RW_READ_VALUE(rw);
 	queue = TS_SHARED_QUEUE;
 	if (v & RW_LOCK_WRITE_WAITERS) {
@@ -1286,10 +1281,7 @@ __rw_wunlock_hard(volatile uintptr_t *c, uintptr_t v LOCK_FILE_LINE_ARG_DEF)
 		    queue == TS_SHARED_QUEUE ? "read" : "write");
 
 	ts = turnstile_lookup(&rw->lock_object);
-	if (__predict_false(ts == NULL)) {
-		panic("got NULL turnstile on rwlock %p passedv %p v %p", rw,
-		    (void *)passedv, (void *)v);
-	}
+	MPASS(ts != NULL);
 	turnstile_broadcast(ts, queue);
 	turnstile_unpend(ts);
 	turnstile_chain_unlock(&rw->lock_object);