diff -r 1918c861ceb0 sys/kern/kern_lock.c
--- a/sys/kern/kern_lock.c	Thu Feb 20 11:24:32 2025 +0000
+++ b/sys/kern/kern_lock.c	Wed Feb 26 17:37:51 2025 +0000
@@ -49,6 +49,7 @@
 #include <sys/atomic.h>
 #include <sys/lwp.h>
 #include <sys/pserialize.h>
+#include <sys/sdt.h>
 
 #if defined(DIAGNOSTIC) && !defined(LOCKDEBUG)
 #include <sys/ksyms.h>
@@ -58,6 +59,11 @@
 
 #include <dev/lockstat.h>
 
+SDT_PROBE_DEFINE2(sdt, kernel, lock, acquire,
+    "int"/*recursiondepth*/, "int"/*nlocks*/);
+SDT_PROBE_DEFINE2(sdt, kernel, lock, release,
+    "int"/*recursiondepth*/, "int"/*nlocks*/);
+
 #define	RETURN_ADDRESS	(uintptr_t)__builtin_return_address(0)
 
 bool	kernel_lock_dodebug;
@@ -214,7 +220,7 @@ void
 		ci->ci_biglock_count += nlocks;
 		l->l_blcnt += nlocks;
 		splx(s);
-		return;
+		goto out;
 	}
 
 	_KERNEL_LOCK_ASSERT(l->l_blcnt == 0);
@@ -230,7 +236,7 @@ void
 		LOCKDEBUG_LOCKED(kernel_lock_dodebug, kernel_lock, NULL,
 		    RETURN_ADDRESS, 0);
 		splx(s);
-		return;
+		goto out;
 	}
 
 	/*
@@ -320,6 +326,9 @@ void
 #ifdef LOCKDEBUG
 	kernel_lock_holder = curcpu();
 #endif
+
+out:	SDT_PROBE2(sdt, kernel, lock, acquire,
+	    ci->ci_biglock_count - nlocks, nlocks);
 }
 
 /*
@@ -353,9 +362,12 @@ void
 		nlocks = 1;
 		_KERNEL_LOCK_ASSERT(olocks == 1);
 	}
+
 	s = splvm();
 	ci = curcpu();
 	_KERNEL_LOCK_ASSERT(ci->ci_biglock_count >= l->l_blcnt);
+	SDT_PROBE2(sdt, kernel, lock, release,
+	    ci->ci_biglock_count - nlocks, nlocks);
 	if (ci->ci_biglock_count == nlocks) {
 		LOCKDEBUG_UNLOCKED(kernel_lock_dodebug, kernel_lock,
 		    RETURN_ADDRESS, 0);