Messages in this thread Patch in this message |  | | Date | Thu, 10 Aug 2017 05:19:12 -0700 | From | tip-bot for Byungchul Park <> | Subject | [tip:locking/core] locking/lockdep: Change the meaning of check_prev_add()'s return value |
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Commit-ID: 70911fdc9576f4eeb3986689a1c9a778a4a4aacb Gitweb: http://git.kernel.org/tip/70911fdc9576f4eeb3986689a1c9a778a4a4aacb Author: Byungchul Park <byungchul.park@lge.com> AuthorDate: Mon, 7 Aug 2017 16:12:50 +0900 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 10 Aug 2017 12:29:06 +0200
locking/lockdep: Change the meaning of check_prev_add()'s return value
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> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-4-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- 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 bdf6b31..7cf02fa 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1881,7 +1881,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, if (entry->class == hlock_class(next)) { if (distance == 1) entry->distance = 1; - return 2; + return 1; } } @@ -1935,9 +1935,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, print_lock_name(hlock_class(next)); printk(KERN_CONT "\n"); dump_stack(); - return graph_lock(); + if (!graph_lock()) + return 0; } - return 1; + return 2; } /*
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