Commit-ID: 70911fdc9576f4eeb3986689a1c9a778a4a4aacb Gitweb: http://git.kernel.org/tip/70911fdc9576f4eeb3986689a1c9a778a4a4aacb Author: Byungchul Park <[email protected]> AuthorDate: Mon, 7 Aug 2017 16:12:50 +0900 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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; } /*
