All of lore.kernel.org
 help / color / mirror / Atom feed
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190318085733.3143-18-duyuyang@gmail.com \
    --to=duyuyang@gmail.com \
    --cc=bvanassche@acm.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ming.lei@redhat.com \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.