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From: Byungchul Park <byungchul.park@lge.com>
To: peterz@infradead.org, mingo@kernel.org
Cc: tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com,
	kirill@shutemov.name, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, akpm@linux-foundation.org,
	willy@infradead.org, npiggin@gmail.com, kernel-team@lge.com
Subject: [PATCH v8 03/14] lockdep: Change the meaning of check_prev_add()'s return value
Date: Mon,  7 Aug 2017 16:12:50 +0900	[thread overview]
Message-ID: <1502089981-21272-4-git-send-email-byungchul.park@lge.com> (raw)
In-Reply-To: <1502089981-21272-1-git-send-email-byungchul.park@lge.com>

Firstly, return 1 instead of 2 when 'prev -> next' dependency already
exists. Since the value 2 is not referenced anywhere, just return 1
indicating success in this case.

Secondly, return 2 instead of 1 when successfully added a lock_list
entry with saving stack_trace. With that, a caller can decide whether
to avoid redundant save_trace() on the caller site.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
 kernel/locking/lockdep.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 9d16723..b23e930 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1870,7 +1870,7 @@ static inline void inc_chains(void)
 		if (entry->class == hlock_class(next)) {
 			if (distance == 1)
 				entry->distance = 1;
-			return 2;
+			return 1;
 		}
 	}
 
@@ -1910,9 +1910,10 @@ static inline void inc_chains(void)
 		print_lock_name(hlock_class(next));
 		printk(KERN_CONT "\n");
 		dump_stack();
-		return graph_lock();
+		if (!graph_lock())
+			return 0;
 	}
-	return 1;
+	return 2;
 }
 
 /*
-- 
1.9.1

  parent reply	other threads:[~2017-08-07  7:16 UTC|newest]

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-07  7:12 [PATCH v8 00/14] lockdep: Implement crossrelease feature Byungchul Park
2017-08-07  7:12 ` [PATCH v8 01/14] lockdep: Refactor lookup_chain_cache() Byungchul Park
2017-08-10 12:18   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 02/14] lockdep: Add a function building a chain between two classes Byungchul Park
2017-08-10 12:18   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` Byungchul Park [this message]
2017-08-10 12:19   ` [tip:locking/core] locking/lockdep: Change the meaning of check_prev_add()'s return value tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 04/14] lockdep: Make check_prev_add() able to handle external stack_trace Byungchul Park
2017-08-10 12:19   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 05/14] lockdep: Implement crossrelease feature Byungchul Park
2017-08-09 14:05   ` Peter Zijlstra
2017-08-10  1:30     ` Byungchul Park
2017-08-10  9:21       ` Peter Zijlstra
2017-08-10 12:19   ` [tip:locking/core] locking/lockdep: Implement the 'crossrelease' feature tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 06/14] lockdep: Detect and handle hist_lock ring buffer overwrite Byungchul Park
2017-08-09 14:16   ` Peter Zijlstra
2017-08-10  1:32     ` Byungchul Park
2017-08-10  9:22       ` Peter Zijlstra
2017-08-10 10:32     ` Byungchul Park
2017-08-10 11:59   ` Boqun Feng
2017-08-10 12:11     ` Byungchul Park
2017-08-10 12:51       ` Boqun Feng
2017-08-10 13:17         ` Boqun Feng
2017-08-11  0:44           ` Byungchul Park
2017-08-11  3:43           ` Byungchul Park
2017-08-11  8:03             ` Boqun Feng
2017-08-11  8:52               ` Byungchul Park
2017-08-11  9:44                 ` Byungchul Park
2017-08-11 13:06                   ` Byungchul Park
2017-08-14  7:05                     ` Boqun Feng
2017-08-14  7:22                       ` Byungchul Park
2017-08-14  7:29                       ` Byungchul Park
2017-08-11  0:40         ` Byungchul Park
2017-08-11  1:03           ` Boqun Feng
2017-08-10 12:20   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 07/14] lockdep: Handle non(or multi)-acquisition of a crosslock Byungchul Park
2017-08-10 12:20   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 08/14] lockdep: Make print_circular_bug() aware of crossrelease Byungchul Park
2017-08-10 12:21   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-07  7:12 ` [PATCH v8 09/14] lockdep: Apply crossrelease to completions Byungchul Park
2017-08-07 10:20   ` kbuild test robot
2017-08-07 11:45   ` kbuild test robot
2017-08-09  9:51   ` Peter Zijlstra
2017-08-09 10:24     ` Peter Zijlstra
2017-08-10  1:24       ` Byungchul Park
2017-08-10 12:21   ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-14  8:50   ` [PATCH v8 09/14] lockdep: " Arnd Bergmann
2017-08-18 23:43     ` Boqun Feng
2017-08-19 12:51       ` Arnd Bergmann
2017-08-19 13:34         ` Arnd Bergmann
2017-08-23 14:43           ` Boqun Feng
2017-08-20  3:18         ` Boqun Feng
2017-08-07  7:12 ` [PATCH v8 10/14] pagemap.h: Remove trailing white space Byungchul Park
2017-08-07  7:12 ` [PATCH v8 11/14] lockdep: Apply crossrelease to PG_locked locks Byungchul Park
2017-08-07 10:36   ` kbuild test robot
2017-08-10  1:35   ` Byungchul Park
2017-08-10  9:25     ` Peter Zijlstra
2017-09-05  1:03   ` Byungchul Park
2017-08-07  7:12 ` [PATCH v8 12/14] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2017-08-07  7:13 ` [PATCH v8 13/14] lockdep: Move data of CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2017-08-07 10:43   ` kbuild test robot
2017-08-07  7:13 ` [PATCH v8 14/14] lockdep: Crossrelease feature documentation Byungchul Park
2017-08-07 15:58   ` kbuild test robot
2017-08-10 12:22   ` [tip:locking/core] locking/lockdep: Add 'crossrelease' " tip-bot for Byungchul Park
2017-08-09 15:50 ` [PATCH v8 00/14] lockdep: Implement crossrelease feature Peter Zijlstra
2017-08-10  0:55   ` Byungchul Park
2017-08-10  3:47     ` Byungchul Park
2017-08-10 10:52     ` Byungchul Park
2017-08-10  9:37   ` Byungchul Park
2017-08-10 10:52     ` Peter Zijlstra
2017-08-10 11:10 ` Ingo Molnar
2017-08-10 11:45   ` Byungchul Park
2017-08-14 10:57     ` Ingo Molnar
2017-08-14 11:10       ` Byungchul Park
2017-08-15  8:20 ` Ingo Molnar
2017-08-16  0:16   ` Byungchul Park
2017-08-16  4:05     ` Boqun Feng
2017-08-16  4:37       ` Byungchul Park
2017-08-16  5:40         ` Boqun Feng
2017-08-16  6:37           ` Byungchul Park
2017-08-16  5:05       ` Byungchul Park
2017-08-16  5:58         ` Boqun Feng
2017-08-16  7:14           ` Byungchul Park
2017-08-16  8:06             ` Byungchul Park
2017-08-16  9:38               ` Byungchul Park
2017-08-17  7:48       ` Ingo Molnar
2017-08-17  8:04         ` Boqun Feng
2017-08-17  8:12           ` Ingo Molnar
2017-08-17  8:33             ` Boqun Feng

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