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From: Yuyang Du <duyuyang@gmail.com>
To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org
Cc: bvanassche@acm.org, ming.lei@redhat.com,
	linux-kernel@vger.kernel.org, Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH v2 17/19] locking/lockdep: Combine check_noncircular and check_redundant
Date: Mon, 18 Mar 2019 16:57:31 +0800	[thread overview]
Message-ID: <20190318085733.3143-18-duyuyang@gmail.com> (raw)
In-Reply-To: <20190318085733.3143-1-duyuyang@gmail.com>

These two functions are essentially duplicates, combine them.

No functional change.

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 kernel/locking/lockdep.c | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 3dbb4d0..90d58cc 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1677,29 +1677,18 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class)
 }
 
 /*
- * Prove that the dependency graph starting at <entry> can not
- * lead to <target>. Print an error and return 0 if it does.
+ * Prove that the dependency graph starting at <root> can not
+ * lead to <target>. If existent, there is a circle when adding
+ * a <target> -> <root> dependency.
+ *
+ * Print an error and return 0 if it does exist.
  */
 static noinline int
-check_noncircular(struct lock_list *root, struct lock_class *target,
+check_nonexistent(struct lock_list *root, struct lock_class *target,
 		  struct lock_list **target_entry)
 {
 	int result;
 
-	debug_atomic_inc(nr_cyclic_checks);
-
-	result = __bfs_forwards(root, target, class_equal, target_entry);
-
-	return result;
-}
-
-static noinline int
-check_redundant(struct lock_list *root, struct lock_class *target,
-		struct lock_list **target_entry)
-{
-	int result;
-
-	debug_atomic_inc(nr_redundant_checks);
 
 	result = __bfs_forwards(root, target, class_equal, target_entry);
 
@@ -2235,7 +2224,8 @@ static void print_deadlock_scenario(struct held_lock *nxt,
 	 */
 	this.class = hlock_class(next);
 	this.parent = NULL;
-	ret = check_noncircular(&this, hlock_class(prev), &target_entry);
+	debug_atomic_inc(nr_cyclic_checks);
+	ret = check_nonexistent(&this, hlock_class(prev), &target_entry);
 	if (unlikely(!ret)) {
 		if (!trace->entries) {
 			/*
@@ -2287,7 +2277,8 @@ static void print_deadlock_scenario(struct held_lock *nxt,
 	 */
 	this.class = hlock_class(prev);
 	this.parent = NULL;
-	ret = check_redundant(&this, hlock_class(next), &target_entry);
+	debug_atomic_inc(nr_redundant_checks);
+	ret = check_nonexistent(&this, hlock_class(next), &target_entry);
 	if (!ret) {
 		debug_atomic_inc(nr_redundant);
 		return 2;
-- 
1.8.3.1


  parent reply	other threads:[~2019-03-18  8:58 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-18  8:57 [PATCH v2 00/19] locking/lockdep: Add comments and make some code Yuyang Du
2019-03-18  8:57 ` [PATCH v2 01/19] locking/lockdep: Change all print_*() return type to void Yuyang Du
2019-03-18  9:45   ` Joe Perches
2019-03-19  3:28     ` Yuyang Du
2019-03-19 16:30     ` Bart Van Assche
2019-03-18  8:57 ` [PATCH v2 02/19] locking/lockdep: Add description and explanation in lockdep design doc Yuyang Du
2019-03-18  8:57 ` [PATCH v2 03/19] locking/lockdep: Adjust lock usage bit character checks Yuyang Du
2019-03-18  8:57 ` [PATCH v2 04/19] locking/lockdep: Remove useless conditional macro Yuyang Du
2019-03-18  8:57 ` [PATCH v2 05/19] locking/lockdep: Adjust indents for function definitions Yuyang Du
2019-03-19 16:33   ` Bart Van Assche
2019-03-19 16:36     ` Peter Zijlstra
2019-03-18  8:57 ` [PATCH v2 06/19] locking/lockdep: Print the right depth for chain key colission Yuyang Du
2019-03-18  8:57 ` [PATCH v2 07/19] locking/lockdep: Update obsolete struct field description Yuyang Du
2019-03-19 16:35   ` Bart Van Assche
2019-03-19 16:44     ` Peter Zijlstra
2019-03-18  8:57 ` [PATCH v2 08/19] locking/lockdep: Use lockdep_init_task for task initiation consistently Yuyang Du
2019-03-18  8:57 ` [PATCH v2 09/19] locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start with Yuyang Du
2019-03-18  8:57 ` [PATCH v2 10/19] locking/lockdep: Change the range of class_idx in held_lock struct Yuyang Du
2019-03-18  8:57 ` [PATCH v2 11/19] locking/lockdep: Remove unused argument in validate_chain() Yuyang Du
2019-03-19 16:45   ` Bart Van Assche
2019-03-18  8:57 ` [PATCH v2 12/19] locking/lockdep: Update comment Yuyang Du
2019-03-18  8:57 ` [PATCH v2 13/19] locking/lockdep: Remove unnecessary function pointer argument Yuyang Du
2019-03-19 16:48   ` Bart Van Assche
2019-03-18  8:57 ` [PATCH v2 14/19] locking/lockdep: Change type of the element field in circular_queue Yuyang Du
2019-03-19 16:50   ` Bart Van Assche
2019-03-19 16:51   ` Bart Van Assche
2019-03-18  8:57 ` [PATCH v2 15/19] locking/lockdep: Remove __cq_empty() Yuyang Du
2019-03-19 16:54   ` Bart Van Assche
2019-03-20  2:30     ` Yuyang Du
2019-03-18  8:57 ` [PATCH v2 16/19] locking/lockdep: Use function pointer to avoid constant checks Yuyang Du
2019-03-19 16:56   ` Bart Van Assche
2019-03-18  8:57 ` Yuyang Du [this message]
2019-03-18  8:57 ` [PATCH v2 18/19] locking/lockdep: Update comments on dependency search Yuyang Du
2019-03-18  8:57 ` [PATCH v2 19/19] locking/lockdep: Change if to else-if when checking bfs errors Yuyang Du
2019-03-19 16:29   ` Bart Van Assche
2019-03-19 17:19     ` Joe Perches
2019-03-20  2:02     ` Yuyang Du

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