diff options
author | Ming Lei <tom.leiming@gmail.com> | 2009-07-16 15:44:29 +0200 |
---|---|---|
committer | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-07-24 10:49:46 +0200 |
commit | d588e46155e9c51217b9840db1e94a0f594c1af2 (patch) | |
tree | 0ede7d7d8338f8db15d8c690c46a0173196d7bac /kernel/lockdep_internals.h | |
parent | lockdep: Print the shortest dependency chain if finding a circle (diff) | |
download | linux-d588e46155e9c51217b9840db1e94a0f594c1af2.tar.xz linux-d588e46155e9c51217b9840db1e94a0f594c1af2.zip |
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 <tom.leiming@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1246201486-7308-3-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/lockdep_internals.h')
-rw-r--r-- | kernel/lockdep_internals.h | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index 6f48d37d5be2..c2f6594966f3 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h @@ -137,23 +137,28 @@ extern atomic_t nr_find_usage_backwards_recursions; # define debug_atomic_read(ptr) 0 #endif + +extern unsigned long nr_list_entries; +extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; +extern unsigned long bfs_accessed[]; + +/*For good efficiency of modular, we use power of 2*/ +#define MAX_CIRCULAR_QUE_SIZE 4096UL + /* The circular_queue and helpers is used to implement the * breadth-first search(BFS)algorithem, by which we can build * the shortest path from the next lock to be acquired to the * previous held lock if there is a circular between them. * */ -#define MAX_CIRCULAR_QUE_SIZE 4096UL struct circular_queue{ unsigned long element[MAX_CIRCULAR_QUE_SIZE]; unsigned int front, rear; }; -#define LOCK_ACCESSED 1UL -#define LOCK_ACCESSED_MASK (~LOCK_ACCESSED) - static inline void __cq_init(struct circular_queue *cq) { cq->front = cq->rear = 0; + bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES); } static inline int __cq_empty(struct circular_queue *cq) @@ -163,7 +168,7 @@ static inline int __cq_empty(struct circular_queue *cq) static inline int __cq_full(struct circular_queue *cq) { - return ((cq->rear + 1)%MAX_CIRCULAR_QUE_SIZE) == cq->front; + return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1)) == cq->front; } static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) @@ -172,7 +177,7 @@ static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) return -1; cq->element[cq->rear] = elem; - cq->rear = (cq->rear + 1)%MAX_CIRCULAR_QUE_SIZE; + cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1); return 0; } @@ -182,30 +187,36 @@ static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) return -1; *elem = cq->element[cq->front]; - cq->front = (cq->front + 1)%MAX_CIRCULAR_QUE_SIZE; + cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1); return 0; } static inline int __cq_get_elem_count(struct circular_queue *cq) { - return (cq->rear - cq->front)%MAX_CIRCULAR_QUE_SIZE; + return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1); } static inline void mark_lock_accessed(struct lock_list *lock, struct lock_list *parent) { - lock->parent = (void *) parent + LOCK_ACCESSED; + unsigned long nr; + nr = lock - list_entries; + WARN_ON(nr >= nr_list_entries); + lock->parent = parent; + set_bit(nr, bfs_accessed); } static inline unsigned long lock_accessed(struct lock_list *lock) { - return (unsigned long)lock->parent & LOCK_ACCESSED; + unsigned long nr; + nr = lock - list_entries; + WARN_ON(nr >= nr_list_entries); + return test_bit(nr, bfs_accessed); } static inline struct lock_list *get_lock_parent(struct lock_list *child) { - return (struct lock_list *) - ((unsigned long)child->parent & LOCK_ACCESSED_MASK); + return child->parent; } static inline unsigned long get_lock_depth(struct lock_list *child) |