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 24/28] locking/lockdep: Remove !dir in lock irq usage check
Date: Wed, 24 Apr 2019 18:19:30 +0800 [thread overview]
Message-ID: <20190424101934.51535-25-duyuyang@gmail.com> (raw)
In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com>
In mark_lock_irq(), the following checks are performed:
----------------------------------
| -> | unsafe | read unsafe |
|----------------------------------|
| safe | F B | F* B* |
|----------------------------------|
| read safe | F? B* | - |
----------------------------------
Where:
F: check_usage_forwards
B: check_usage_backwards
*: check enabled by STRICT_READ_CHECKS
?: check enabled by the !dir condition
From checking point of view, the special F? case does not make sense,
whereas it perhaps is made for peroformance concern. As later patch will
address this issue, remove this exception, which makes the checks
consistent later.
With STRICT_READ_CHECKS = 1 which is default, there is no functional
change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
kernel/locking/lockdep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 1b78216..2f24028 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3149,7 +3149,7 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
* Validate that the lock dependencies don't have conflicting usage
* states.
*/
- if ((!read || !dir || STRICT_READ_CHECKS) &&
+ if ((!read || STRICT_READ_CHECKS) &&
!usage(curr, this, excl_bit, state_name(new_bit & ~LOCK_USAGE_READ_MASK)))
return 0;
--
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 ` [PATCH 12/28] locking/lockdep: Change type of the element field in circular_queue Yuyang Du
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 ` Yuyang Du [this message]
2019-04-25 20:03 ` [PATCH 24/28] locking/lockdep: Remove !dir in lock irq usage check 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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