From 12f3dfd022d7e616757a94f0538d3d525d806a16 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 16 Jul 2009 15:44:29 +0200 Subject: [PATCH] lockdep: Add statistics info for max bfs queue depth Add BFS statistics to the existing lockdep stats. Signed-off-by: Ming Lei Signed-off-by: Peter Zijlstra LKML-Reference: <1246201486-7308-10-git-send-email-tom.leiming@gmail.com> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 6 +++++- kernel/lockdep_internals.h | 3 ++- kernel/lockdep_proc.c | 2 ++ 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 6358cf7e84b..744da6265d9 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -929,7 +929,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)]; static struct circular_queue lock_cq; - +unsigned int max_bfs_queue_depth; static int __bfs(struct lock_list *source_entry, void *data, int (*match)(struct lock_list *entry, void *data), @@ -975,6 +975,7 @@ static int __bfs(struct lock_list *source_entry, list_for_each_entry(entry, head, entry) { if (!lock_accessed(entry)) { + unsigned int cq_depth; mark_lock_accessed(entry, lock); if (match(entry, data)) { *target_entry = entry; @@ -986,6 +987,9 @@ static int __bfs(struct lock_list *source_entry, ret = -1; goto exit; } + cq_depth = __cq_get_elem_count(cq); + if (max_bfs_queue_depth < cq_depth) + max_bfs_queue_depth = cq_depth; } } } diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index b115aaa0bf3..6baa8807efd 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h @@ -138,6 +138,7 @@ extern atomic_t nr_find_usage_backwards_recursions; #endif +extern unsigned int max_bfs_queue_depth; extern unsigned long nr_list_entries; extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; extern unsigned long bfs_accessed[]; @@ -191,7 +192,7 @@ static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) return 0; } -static inline int __cq_get_elem_count(struct circular_queue *cq) +static inline unsigned int __cq_get_elem_count(struct circular_queue *cq) { return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1); } diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index d7135aa2d2c..9a1bf34d2ff 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -411,6 +411,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v) max_lockdep_depth); seq_printf(m, " max recursion depth: %11u\n", max_recursion_depth); + seq_printf(m, " max bfs queue depth: %11u\n", + max_bfs_queue_depth); lockdep_stats_debug_show(m); seq_printf(m, " debug_locks: %11u\n", debug_locks);