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, joe@perches.com,
Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH v3 11/18] locking/lockdep: Update comment
Date: Thu, 21 Mar 2019 15:57:18 +0800 [thread overview]
Message-ID: <20190321075725.14054-12-duyuyang@gmail.com> (raw)
In-Reply-To: <20190321075725.14054-1-duyuyang@gmail.com>
An out-of-nowhere comment is removed. While at it, add more explanatory
comments. Such a trivial patch!
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
kernel/locking/lockdep.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c7aec9f..eccfb0b 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2720,10 +2720,16 @@ static int validate_chain(struct task_struct *curr,
* - is softirq-safe, if this lock is hardirq-unsafe
*
* And check whether the new lock's dependency graph
- * could lead back to the previous lock.
+ * could lead back to the previous lock:
*
- * any of these scenarios could lead to a deadlock. If
- * All validations
+ * - within the current held-lock stack
+ * - across our accumulated lock dependency records
+ *
+ * any of these scenarios could lead to a deadlock.
+ */
+ /*
+ * The simple case: does the current hold the same lock
+ * already?
*/
int ret = check_deadlock(curr, hlock, hlock->read);
--
1.8.3.1
next prev parent reply other threads:[~2019-03-21 7:58 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 7:57 [PATCH v3 00/18] locking/lockdep: Add comments and make some code Yuyang Du
2019-03-21 7:57 ` [PATCH v3 01/18] locking/lockdep: Change all print_*() return type to void Yuyang Du
2019-03-21 7:57 ` [PATCH v3 02/18] locking/lockdep: Add description and explanation in lockdep design doc Yuyang Du
2019-03-21 7:57 ` [PATCH v3 03/18] locking/lockdep: Adjust lock usage bit character checks Yuyang Du
2019-03-21 7:57 ` [PATCH v3 04/18] locking/lockdep: Remove useless conditional macro Yuyang Du
2019-03-21 7:57 ` [PATCH v3 05/18] locking/lockdep: Print the right depth for chain key colission Yuyang Du
2019-03-21 7:57 ` [PATCH v3 06/18] locking/lockdep: Update obsolete struct field description Yuyang Du
2019-03-21 7:57 ` [PATCH v3 07/18] locking/lockdep: Use lockdep_init_task for task initiation consistently Yuyang Du
2019-03-21 7:57 ` [PATCH v3 08/18] locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start with Yuyang Du
2019-03-21 7:57 ` [PATCH v3 09/18] locking/lockdep: Change the range of class_idx in held_lock struct Yuyang Du
2019-03-21 7:57 ` [PATCH v3 10/18] locking/lockdep: Remove unused argument in validate_chain() and check_deadlock() Yuyang Du
2019-03-21 7:57 ` Yuyang Du [this message]
2019-03-21 7:57 ` [PATCH v3 12/18] locking/lockdep: Remove unnecessary function pointer argument Yuyang Du
2019-03-21 7:57 ` [PATCH v3 13/18] locking/lockdep: Change type of the element field in circular_queue Yuyang Du
2019-03-21 7:57 ` [PATCH v3 14/18] locking/lockdep: Change the return type of __cq_dequeue() Yuyang Du
2019-03-21 7:57 ` [PATCH v3 15/18] locking/lockdep: Avoid constant checks in __bfs by using offset reference Yuyang Du
2019-03-21 7:57 ` [PATCH v3 16/18] locking/lockdep: Combine check_noncircular and check_redundant Yuyang Du
2019-03-21 7:57 ` [PATCH v3 17/18] locking/lockdep: Update comments on dependency search Yuyang Du
2019-03-21 7:57 ` [PATCH v3 18/18] locking/lockdep: Add explanation to lock usage rules in lockdep design doc Yuyang Du
2019-04-04 5:03 ` Question on a lockdep test case about mixed read-write ABBA Yuyang Du
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