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, frederic@kernel.org,
tglx@linutronix.de, linux-kernel@vger.kernel.org,
Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH 12/28] locking/lockdep: Change type of the element field in circular_queue
Date: Wed, 24 Apr 2019 18:19:18 +0800 [thread overview]
Message-ID: <20190424101934.51535-13-duyuyang@gmail.com> (raw)
In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com>
The element field is an array in struct circular_queue to keep track of locks
in the search. Making it the same type as the locks avoids type cast. Also
fix a typo and elaborate the comment above struct circular_queue.
No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
kernel/locking/lockdep.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 0543872..683aaf60 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1257,13 +1257,16 @@ static int add_lock_to_list(struct lock_class *this,
#define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1)
/*
- * The circular_queue and helpers is used to implement the
- * breadth-first search(BFS)algorithem, by which we can build
- * the shortest path from the next lock to be acquired to the
- * previous held lock if there is a circular between them.
+ * The circular_queue and helpers are used to implement the graph
+ * breadth-first search (BFS) algorithm, by which we can determine whether
+ * there is a path from the next lock to be acquired to a previous held
+ * lock, which indicates that adding the <prev> -> <next> lock dependency
+ * produces a circle in the lock dependency graph. Breadth-first search
+ * instead of depth-first search is used for finding the shortest circular
+ * path.
*/
struct circular_queue {
- unsigned long element[MAX_CIRCULAR_QUEUE_SIZE];
+ struct lock_list *element[MAX_CIRCULAR_QUEUE_SIZE];
unsigned int front, rear;
};
@@ -1289,7 +1292,7 @@ static inline int __cq_full(struct circular_queue *cq)
return ((cq->rear + 1) & CQ_MASK) == cq->front;
}
-static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
+static inline int __cq_enqueue(struct circular_queue *cq, struct lock_list *elem)
{
if (__cq_full(cq))
return -1;
@@ -1299,7 +1302,7 @@ static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
return 0;
}
-static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
+static inline int __cq_dequeue(struct circular_queue *cq, struct lock_list **elem)
{
if (__cq_empty(cq))
return -1;
@@ -1377,12 +1380,12 @@ static int __bfs(struct lock_list *source_entry,
goto exit;
__cq_init(cq);
- __cq_enqueue(cq, (unsigned long)source_entry);
+ __cq_enqueue(cq, source_entry);
while (!__cq_empty(cq)) {
struct lock_list *lock;
- __cq_dequeue(cq, (unsigned long *)&lock);
+ __cq_dequeue(cq, &lock);
if (!lock->class) {
ret = -2;
@@ -1406,7 +1409,7 @@ static int __bfs(struct lock_list *source_entry,
goto exit;
}
- if (__cq_enqueue(cq, (unsigned long)entry)) {
+ if (__cq_enqueue(cq, entry)) {
ret = -1;
goto exit;
}
--
1.8.3.1
next prev parent reply other threads:[~2019-04-24 10:22 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 10:19 [PATCH 00/28] Optimize IRQ usage checks and other small bits Yuyang Du
2019-04-24 10:19 ` [PATCH 01/28] locking/lockdep: Change all print_*() return type to void Yuyang Du
2019-04-24 10:19 ` [PATCH 02/28] locking/lockdep: Add description and explanation in lockdep design doc Yuyang Du
2019-04-25 14:01 ` Peter Zijlstra
2019-04-26 5:41 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 03/28] locking/lockdep: Adjust lock usage bit character checks Yuyang Du
2019-04-24 10:19 ` [PATCH 04/28] locking/lockdep: Remove useless conditional macro Yuyang Du
2019-04-24 10:19 ` [PATCH 05/28] locking/lockdep: Print the right depth for chain key colission Yuyang Du
2019-04-24 10:19 ` [PATCH 06/28] locking/lockdep: Update obsolete struct field description Yuyang Du
2019-04-24 10:19 ` [PATCH 07/28] locking/lockdep: Use lockdep_init_task for task initiation consistently Yuyang Du
2019-04-24 10:19 ` [PATCH 08/28] locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start with Yuyang Du
2019-04-24 10:19 ` [PATCH 09/28] locking/lockdep: Change the range of class_idx in held_lock struct Yuyang Du
2019-04-24 10:19 ` [PATCH 10/28] locking/lockdep: Remove unused argument in validate_chain() and check_deadlock() Yuyang Du
2019-04-24 10:19 ` [PATCH 11/28] locking/lockdep: Update comment Yuyang Du
2019-04-24 10:19 ` Yuyang Du [this message]
2019-04-24 10:19 ` [PATCH 13/28] locking/lockdep: Change the return type of __cq_dequeue() Yuyang Du
2019-04-24 10:19 ` [PATCH 14/28] locking/lockdep: Avoid constant checks in __bfs by using offset reference Yuyang Du
2019-04-24 10:19 ` [PATCH 15/28] locking/lockdep: Update comments on dependency search Yuyang Du
2019-04-24 10:19 ` [PATCH 16/28] locking/lockdep: Add explanation to lock usage rules in lockdep design doc Yuyang Du
2019-04-24 10:19 ` [PATCH 17/28] locking/lockdep: Remove redundant argument in check_deadlock Yuyang Du
2019-04-24 10:19 ` [PATCH 18/28] locking/lockdep: Remove unused argument in __lock_release Yuyang Du
2019-04-24 10:19 ` [PATCH 19/28] locking/lockdep: Optimize irq usage check when marking lock usage bit Yuyang Du
2019-04-25 19:32 ` Peter Zijlstra
2019-04-26 6:57 ` Yuyang Du
2019-04-30 12:11 ` Peter Zijlstra
2019-05-06 3:05 ` Yuyang Du
2019-05-06 3:42 ` Yuyang Du
2019-05-07 1:47 ` Frederic Weisbecker
2019-05-07 2:21 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 20/28] locking/lockdep: Refactorize check_noncircular and check_redundant Yuyang Du
2019-04-25 19:48 ` Peter Zijlstra
2019-04-26 6:48 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 21/28] locking/lockdep: Consolidate lock usage bit initialization Yuyang Du
2019-04-24 10:19 ` [PATCH 22/28] locking/lockdep: Adjust new bit cases in mark_lock Yuyang Du
2019-04-25 19:52 ` Peter Zijlstra
2019-04-26 6:47 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 23/28] locking/lockdep: Update irqsafe lock bitmaps Yuyang Du
2019-04-25 19:55 ` Peter Zijlstra
2019-04-26 6:45 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 24/28] locking/lockdep: Remove !dir in lock irq usage check Yuyang Du
2019-04-25 20:03 ` Peter Zijlstra
2019-04-26 7:06 ` Yuyang Du
2019-04-26 7:25 ` Boqun Feng
2019-04-30 15:35 ` Peter Zijlstra
2019-04-24 10:19 ` [PATCH 25/28] locking/lockdep: Implement new IRQ usage checking algorithm Yuyang Du
2019-04-24 10:19 ` [PATCH 26/28] locking/lockdep: Remove __bfs Yuyang Du
2019-04-25 20:06 ` Peter Zijlstra
2019-04-26 6:35 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 27/28] locking/lockdep: Remove locks_before Yuyang Du
2019-04-24 10:19 ` [PATCH 28/28] locking/lockdep: Reduce lock_list_entries by half Yuyang Du
2019-04-25 18:56 ` [PATCH 00/28] Optimize IRQ usage checks and other small bits Peter Zijlstra
2019-04-26 6:59 ` Yuyang Du
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