Messages in this thread Patch in this message | | | From | Xiongwei Song <> | Subject | [PATCH 1/3] locking/lockdep: unlikely bfs_error() inside | Date | Thu, 17 Jun 2021 22:28:26 +0800 |
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From: Xiongwei Song <sxwjean@gmail.com>
The error from graph walk is small probability event, and there are some bfs_error calls during lockdep detection, so unlikely bfs_error inside can improve performance a little bit.
Suggested-by: Waiman Long <longman@redhat.com> Signed-off-by: Xiongwei Song <sxwjean@gmail.com> --- kernel/locking/lockdep.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 7641bd407239..a8a66a2a9bc1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1540,7 +1540,7 @@ enum bfs_result { */ static inline bool bfs_error(enum bfs_result res) { - return res < 0; + return unlikely(res < 0); } /* @@ -2089,7 +2089,7 @@ check_path(struct held_lock *target, struct lock_list *src_entry, ret = __bfs_forwards(src_entry, target, match, skip, target_entry); - if (unlikely(bfs_error(ret))) + if (bfs_error(ret)) print_bfs_bug(ret); return ret; @@ -2936,7 +2936,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * in the graph whose neighbours are to be checked. */ ret = check_noncircular(next, prev, trace); - if (unlikely(bfs_error(ret) || ret == BFS_RMATCH)) + if (bfs_error(ret) || unlikely(ret == BFS_RMATCH)) return 0; if (!check_irq_usage(curr, prev, next)) -- 2.30.2
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