diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index a3fda9f..ddc05e7 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -33,7 +33,8 @@
  */
 static inline void mmgrab(struct mm_struct *mm)
 {
-	atomic_inc(&mm->mm_count);
+	printk("mmgrab %p to %d\n", mm, atomic_inc_return(&mm->mm_count));
+	dump_stack();
 }
 
 extern void __mmdrop(struct mm_struct *mm);
@@ -45,6 +46,8 @@ static inline void mmdrop(struct mm_struct *mm)
 	 * required by the membarrier system call before returning to
 	 * user-space, after storing to rq->curr.
 	 */
+	printk("mmdrop %p before %d\n", mm, atomic_read(&mm->mm_count));
+	dump_stack();
 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
 		__mmdrop(mm);
 }
@@ -88,11 +91,14 @@ static inline bool mmget_still_valid(struct mm_struct *mm)
  */
 static inline void mmget(struct mm_struct *mm)
 {
-	atomic_inc(&mm->mm_users);
+	printk("mget %p to %d\n", mm, atomic_inc_return(&mm->mm_users));
+	dump_stack();
 }
 
 static inline bool mmget_not_zero(struct mm_struct *mm)
 {
+	printk("mmget_not_zero %p\n", mm);
+	dump_stack();
 	return atomic_inc_not_zero(&mm->mm_users);
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index b2b87d4..80efe50 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1076,6 +1076,8 @@ void mmput(struct mm_struct *mm)
 {
 	might_sleep();
 
+	printk("mmput mm %p before %d\n", mm, atomic_read(&mm->mm_users));
+	dump_stack();
 	if (atomic_dec_and_test(&mm->mm_users))
 		__mmput(mm);
 }