lockdep: Add statistics info for max bfs queue depth
[linux-2.6.git] / kernel / lockdep_internals.h
1 /*
2  * kernel/lockdep_internals.h
3  *
4  * Runtime locking correctness validator
5  *
6  * lockdep subsystem internal functions and variables.
7  */
8
9 /*
10  * Lock-class usage-state bits:
11  */
12 enum lock_usage_bit {
13 #define LOCKDEP_STATE(__STATE)          \
14         LOCK_USED_IN_##__STATE,         \
15         LOCK_USED_IN_##__STATE##_READ,  \
16         LOCK_ENABLED_##__STATE,         \
17         LOCK_ENABLED_##__STATE##_READ,
18 #include "lockdep_states.h"
19 #undef LOCKDEP_STATE
20         LOCK_USED,
21         LOCK_USAGE_STATES
22 };
23
24 /*
25  * Usage-state bitmasks:
26  */
27 #define __LOCKF(__STATE)        LOCKF_##__STATE = (1 << LOCK_##__STATE),
28
29 enum {
30 #define LOCKDEP_STATE(__STATE)                                          \
31         __LOCKF(USED_IN_##__STATE)                                      \
32         __LOCKF(USED_IN_##__STATE##_READ)                               \
33         __LOCKF(ENABLED_##__STATE)                                      \
34         __LOCKF(ENABLED_##__STATE##_READ)
35 #include "lockdep_states.h"
36 #undef LOCKDEP_STATE
37         __LOCKF(USED)
38 };
39
40 #define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
41 #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
42
43 #define LOCKF_ENABLED_IRQ_READ \
44                 (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
45 #define LOCKF_USED_IN_IRQ_READ \
46                 (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
47
48 /*
49  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
50  * we track.
51  *
52  * We use the per-lock dependency maps in two ways: we grow it by adding
53  * every to-be-taken lock to all currently held lock's own dependency
54  * table (if it's not there yet), and we check it for lock order
55  * conflicts and deadlocks.
56  */
57 #define MAX_LOCKDEP_ENTRIES     16384UL
58
59 #define MAX_LOCKDEP_CHAINS_BITS 15
60 #define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)
61
62 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
63
64 /*
65  * Stack-trace: tightly packed array of stack backtrace
66  * addresses. Protected by the hash_lock.
67  */
68 #define MAX_STACK_TRACE_ENTRIES 262144UL
69
70 extern struct list_head all_lock_classes;
71 extern struct lock_chain lock_chains[];
72
73 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
74
75 extern void get_usage_chars(struct lock_class *class,
76                             char usage[LOCK_USAGE_CHARS]);
77
78 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
79
80 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
81
82 extern unsigned long nr_lock_classes;
83 extern unsigned long nr_list_entries;
84 extern unsigned long nr_lock_chains;
85 extern int nr_chain_hlocks;
86 extern unsigned long nr_stack_trace_entries;
87
88 extern unsigned int nr_hardirq_chains;
89 extern unsigned int nr_softirq_chains;
90 extern unsigned int nr_process_chains;
91 extern unsigned int max_lockdep_depth;
92 extern unsigned int max_recursion_depth;
93
94 #ifdef CONFIG_PROVE_LOCKING
95 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
96 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
97 #else
98 static inline unsigned long
99 lockdep_count_forward_deps(struct lock_class *class)
100 {
101         return 0;
102 }
103 static inline unsigned long
104 lockdep_count_backward_deps(struct lock_class *class)
105 {
106         return 0;
107 }
108 #endif
109
110 #ifdef CONFIG_DEBUG_LOCKDEP
111 /*
112  * Various lockdep statistics:
113  */
114 extern atomic_t chain_lookup_hits;
115 extern atomic_t chain_lookup_misses;
116 extern atomic_t hardirqs_on_events;
117 extern atomic_t hardirqs_off_events;
118 extern atomic_t redundant_hardirqs_on;
119 extern atomic_t redundant_hardirqs_off;
120 extern atomic_t softirqs_on_events;
121 extern atomic_t softirqs_off_events;
122 extern atomic_t redundant_softirqs_on;
123 extern atomic_t redundant_softirqs_off;
124 extern atomic_t nr_unused_locks;
125 extern atomic_t nr_cyclic_checks;
126 extern atomic_t nr_cyclic_check_recursions;
127 extern atomic_t nr_find_usage_forwards_checks;
128 extern atomic_t nr_find_usage_forwards_recursions;
129 extern atomic_t nr_find_usage_backwards_checks;
130 extern atomic_t nr_find_usage_backwards_recursions;
131 # define debug_atomic_inc(ptr)          atomic_inc(ptr)
132 # define debug_atomic_dec(ptr)          atomic_dec(ptr)
133 # define debug_atomic_read(ptr)         atomic_read(ptr)
134 #else
135 # define debug_atomic_inc(ptr)          do { } while (0)
136 # define debug_atomic_dec(ptr)          do { } while (0)
137 # define debug_atomic_read(ptr)         0
138 #endif
139
140
141 extern unsigned int max_bfs_queue_depth;
142 extern unsigned long nr_list_entries;
143 extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
144 extern unsigned long bfs_accessed[];
145
146 /*For good efficiency of modular, we use power of 2*/
147 #define  MAX_CIRCULAR_QUE_SIZE      4096UL
148
149 /* The circular_queue and helpers is used to implement the
150  * breadth-first search(BFS)algorithem, by which we can build
151  * the shortest path from the next lock to be acquired to the
152  * previous held lock if there is a circular between them.
153  * */
154 struct circular_queue{
155         unsigned long element[MAX_CIRCULAR_QUE_SIZE];
156         unsigned int  front, rear;
157 };
158
159 static inline void __cq_init(struct circular_queue *cq)
160 {
161         cq->front = cq->rear = 0;
162         bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
163 }
164
165 static inline int __cq_empty(struct circular_queue *cq)
166 {
167         return (cq->front == cq->rear);
168 }
169
170 static inline int __cq_full(struct circular_queue *cq)
171 {
172         return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1))  == cq->front;
173 }
174
175 static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
176 {
177         if (__cq_full(cq))
178                 return -1;
179
180         cq->element[cq->rear] = elem;
181         cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
182         return 0;
183 }
184
185 static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
186 {
187         if (__cq_empty(cq))
188                 return -1;
189
190         *elem = cq->element[cq->front];
191         cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
192         return 0;
193 }
194
195 static inline unsigned int  __cq_get_elem_count(struct circular_queue *cq)
196 {
197         return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1);
198 }
199
200 static inline void mark_lock_accessed(struct lock_list *lock,
201                                         struct lock_list *parent)
202 {
203         unsigned long nr;
204         nr = lock - list_entries;
205         WARN_ON(nr >= nr_list_entries);
206         lock->parent = parent;
207         set_bit(nr, bfs_accessed);
208 }
209
210 static inline unsigned long lock_accessed(struct lock_list *lock)
211 {
212         unsigned long nr;
213         nr = lock - list_entries;
214         WARN_ON(nr >= nr_list_entries);
215         return test_bit(nr, bfs_accessed);
216 }
217
218 static inline struct lock_list *get_lock_parent(struct lock_list *child)
219 {
220         return child->parent;
221 }
222
223 static inline int get_lock_depth(struct lock_list *child)
224 {
225         int depth = 0;
226         struct lock_list *parent;
227
228         while ((parent = get_lock_parent(child))) {
229                 child = parent;
230                 depth++;
231         }
232         return depth;
233 }