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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, frederic@kernel.org,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	longman@redhat.com, paulmck@linux.vnet.ibm.com,
	boqun.feng@gmail.com, Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH v3 06/30] locking/lockdep: Update comments in struct lock_list and held_lock
Date: Fri, 28 Jun 2019 17:15:04 +0800	[thread overview]
Message-ID: <20190628091528.17059-7-duyuyang@gmail.com> (raw)
In-Reply-To: <20190628091528.17059-1-duyuyang@gmail.com>

The comments regarding initial chain key and BFS are outdated so update them.

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 include/linux/lockdep.h | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 3c6fb63..5e0a1a9 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -198,8 +198,7 @@ struct lock_list {
 	int				distance;
 
 	/*
-	 * The parent field is used to implement breadth-first search, and the
-	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
+	 * The parent field is used to implement breadth-first search.
 	 */
 	struct lock_list		*parent;
 };
@@ -242,7 +241,7 @@ struct held_lock {
 	 * as likely as possible - hence the 64-bit width.
 	 *
 	 * The task struct holds the current hash value (initialized
-	 * with zero), here we store the previous hash value:
+	 * with INITIAL_CHAIN_KEY), here we store the previous hash value:
 	 */
 	u64				prev_chain_key;
 	unsigned long			acquire_ip;
@@ -261,12 +260,12 @@ struct held_lock {
 	/*
 	 * The lock-stack is unified in that the lock chains of interrupt
 	 * contexts nest ontop of process context chains, but we 'separate'
-	 * the hashes by starting with 0 if we cross into an interrupt
-	 * context, and we also keep do not add cross-context lock
-	 * dependencies - the lock usage graph walking covers that area
-	 * anyway, and we'd just unnecessarily increase the number of
-	 * dependencies otherwise. [Note: hardirq and softirq contexts
-	 * are separated from each other too.]
+	 * the hashes by starting with a new chain if we cross into an
+	 * interrupt context, and we also keep not adding cross-context
+	 * lock dependencies - the lock usage graph walking covers that
+	 * area anyway, and we'd just unnecessarily increase the number
+	 * of dependencies otherwise. [Note: hardirq and softirq
+	 * contexts are separated from each other too.]
 	 *
 	 * The following field is used to detect when we cross into an
 	 * interrupt context:
-- 
1.8.3.1


  parent reply	other threads:[~2019-06-28  9:16 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-28  9:14 [PATCH v3 00/30] Support recursive-read lock deadlock detection Yuyang Du
2019-06-28  9:14 ` [PATCH v3 01/30] locking/lockdep: Rename deadlock check functions Yuyang Du
2019-06-28  9:15 ` [PATCH v3 02/30] locking/lockdep: Change return type of add_chain_cache() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 03/30] locking/lockdep: Change return type of lookup_chain_cache_add() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 04/30] locking/lockdep: Pass lock chain from validate_chain() to check_prev_add() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 05/30] locking/lockdep: Add lock chain list_head field in struct lock_list and lock_chain Yuyang Du
2019-06-28  9:15 ` Yuyang Du [this message]
2019-06-28  9:15 ` [PATCH v3 07/30] locking/lockdep: Remove indirect dependency redundancy check Yuyang Du
2019-06-28  9:15 ` [PATCH v3 08/30] locking/lockdep: Skip checks if direct dependency is already present Yuyang Du
2019-06-28  9:15 ` [PATCH v3 09/30] locking/lockdep: Remove chain_head argument in validate_chain() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 10/30] locking/lockdep: Remove useless lock type assignment Yuyang Du
2019-06-28  9:15 ` [PATCH v3 11/30] locking/lockdep: Specify the depth of current lock stack in lookup_chain_cache_add() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 12/30] locking/lockdep: Treat every lock dependency as in a new lock chain Yuyang Du
2019-06-28  9:15 ` [PATCH v3 13/30] locking/lockdep: Combine lock_lists in struct lock_class into an array Yuyang Du
2019-06-28  9:15 ` [PATCH v3 14/30] locking/lockdep: Consolidate forward and backward lock_lists into one Yuyang Du
2019-06-28  9:15 ` [PATCH v3 15/30] locking/lockdep: Add lock chains to direct lock dependency graph Yuyang Du
2019-06-28  9:15 ` [PATCH v3 16/30] locking/lockdep: Use lock type enum to explicitly specify read or write locks Yuyang Du
2019-06-28  9:15 ` [PATCH v3 17/30] locking/lockdep: Add read-write type for a lock dependency Yuyang Du
2019-07-10  5:18   ` Boqun Feng
2019-07-11  5:02     ` Yuyang Du
2019-06-28  9:15 ` [PATCH v3 18/30] locking/lockdep: Add helper functions to operate on the searched path Yuyang Du
2019-06-28  9:15 ` [PATCH v3 19/30] locking/lockdep: Update direct dependency's read-write type if it exists Yuyang Du
2019-06-28  9:15 ` [PATCH v3 20/30] locking/lockdep: Introduce chain_hlocks_type for held lock's read-write type Yuyang Du
2019-06-28  9:15 ` [PATCH v3 21/30] locking/lockdep: Hash held lock's read-write type into chain key Yuyang Du
2019-06-28  9:15 ` [PATCH v3 22/30] locking/lockdep: Adjust BFS algorithm to support multiple matches Yuyang Du
2019-06-28  9:15 ` [PATCH v3 23/30] locking/lockdep: Define the two task model for lockdep checks formally Yuyang Du
2019-06-28  9:15 ` [PATCH v3 24/30] locking/lockdep: Introduce mark_lock_unaccessed() Yuyang Du
2019-06-28  9:15 ` [PATCH v3 25/30] locking/lockdep: Add nest lock type Yuyang Du
2019-06-28  9:15 ` [PATCH v3 26/30] locking/lockdep: Add lock exclusiveness table Yuyang Du
2019-06-28  9:15 ` [PATCH v3 27/30] locking/lockdep: Support read-write lock's deadlock detection Yuyang Du
2019-06-28  9:15 ` [PATCH v3 28/30] locking/lockdep: Adjust selftest case for recursive read lock Yuyang Du
2019-06-28  9:15 ` [PATCH v3 29/30] locking/lockdep: Add more lockdep selftest cases Yuyang Du
2019-06-28  9:15 ` [PATCH v3 30/30] locking/lockdep: Remove irq-safe to irq-unsafe read check Yuyang Du
2019-07-10  5:30   ` Boqun Feng
2019-07-10  6:30     ` Yuyang Du
2019-07-10  1:54 ` [PATCH v3 00/30] Support recursive-read lock deadlock detection Yuyang Du

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