From d588e46155e9c51217b9840db1e94a0f594c1af2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 16 Jul 2009 15:44:29 +0200 Subject: lockdep: Improve implementation of BFS 1,replace %MAX_CIRCULAR_QUE_SIZE with &(MAX_CIRCULAR_QUE_SIZE-1) since we define MAX_CIRCULAR_QUE_SIZE as power of 2; 2,use bitmap to mark if a lock is accessed in BFS in order to clear it quickly, because we may search a graph many times. Signed-off-by: Ming Lei Signed-off-by: Peter Zijlstra LKML-Reference: <1246201486-7308-3-git-send-email-tom.leiming@gmail.com> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 93dc70d..5dcca26 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -42,7 +42,7 @@ #include #include #include - +#include #include #include "lockdep_internals.h" @@ -118,7 +118,7 @@ static inline int debug_locks_off_graph_unlock(void) static int lockdep_initialized; unsigned long nr_list_entries; -static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; +struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; /* * All data structures here are protected by the global debug_lock. @@ -897,30 +897,38 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 1; } +unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)]; static struct circular_queue lock_cq; + static int __search_shortest_path(struct lock_list *source_entry, struct lock_class *target, struct lock_list **target_entry, int forward) { struct lock_list *entry; + struct list_head *head; struct circular_queue *cq = &lock_cq; int ret = 1; - __cq_init(cq); - - mark_lock_accessed(source_entry, NULL); if (source_entry->class == target) { *target_entry = source_entry; ret = 0; goto exit; } + if (forward) + head = &source_entry->class->locks_after; + else + head = &source_entry->class->locks_before; + + if (list_empty(head)) + goto exit; + + __cq_init(cq); __cq_enqueue(cq, (unsigned long)source_entry); while (!__cq_empty(cq)) { struct lock_list *lock; - struct list_head *head; __cq_dequeue(cq, (unsigned long *)&lock); @@ -1040,6 +1048,7 @@ static noinline int print_circular_bug(void) return 0; this.class = hlock_class(check_source); + this.parent = NULL; if (!save_trace(&this.trace)) return 0; @@ -1580,10 +1589,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, */ check_source = next; check_target = prev; + if (check_noncircular(hlock_class(next), 0) == 2) return print_circular_bug(); - if (!check_prev_add_irq(curr, prev, next)) return 0; -- cgit v1.1