ia64/linux-2.6.18-xen.hg

view lib/spinlock_debug.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /*
2 * Copyright 2005, Red Hat, Inc., Ingo Molnar
3 * Released under the General Public License (GPL).
4 *
5 * This file contains the spinlock/rwlock implementations for
6 * DEBUG_SPINLOCK.
7 */
9 #include <linux/spinlock.h>
10 #include <linux/interrupt.h>
11 #include <linux/debug_locks.h>
12 #include <linux/delay.h>
13 #include <linux/module.h>
15 void __spin_lock_init(spinlock_t *lock, const char *name,
16 struct lock_class_key *key)
17 {
18 #ifdef CONFIG_DEBUG_LOCK_ALLOC
19 /*
20 * Make sure we are not reinitializing a held lock:
21 */
22 debug_check_no_locks_freed((void *)lock, sizeof(*lock));
23 lockdep_init_map(&lock->dep_map, name, key);
24 #endif
25 lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
26 lock->magic = SPINLOCK_MAGIC;
27 lock->owner = SPINLOCK_OWNER_INIT;
28 lock->owner_cpu = -1;
29 }
31 EXPORT_SYMBOL(__spin_lock_init);
33 void __rwlock_init(rwlock_t *lock, const char *name,
34 struct lock_class_key *key)
35 {
36 #ifdef CONFIG_DEBUG_LOCK_ALLOC
37 /*
38 * Make sure we are not reinitializing a held lock:
39 */
40 debug_check_no_locks_freed((void *)lock, sizeof(*lock));
41 lockdep_init_map(&lock->dep_map, name, key);
42 #endif
43 lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED;
44 lock->magic = RWLOCK_MAGIC;
45 lock->owner = SPINLOCK_OWNER_INIT;
46 lock->owner_cpu = -1;
47 }
49 EXPORT_SYMBOL(__rwlock_init);
51 static void spin_bug(spinlock_t *lock, const char *msg)
52 {
53 struct task_struct *owner = NULL;
55 if (!debug_locks_off())
56 return;
58 if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
59 owner = lock->owner;
60 printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
61 msg, raw_smp_processor_id(),
62 current->comm, current->pid);
63 printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, "
64 ".owner_cpu: %d\n",
65 lock, lock->magic,
66 owner ? owner->comm : "<none>",
67 owner ? owner->pid : -1,
68 lock->owner_cpu);
69 dump_stack();
70 }
72 #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
74 static inline void
75 debug_spin_lock_before(spinlock_t *lock)
76 {
77 SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
78 SPIN_BUG_ON(lock->owner == current, lock, "recursion");
79 SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
80 lock, "cpu recursion");
81 }
83 static inline void debug_spin_lock_after(spinlock_t *lock)
84 {
85 lock->owner_cpu = raw_smp_processor_id();
86 lock->owner = current;
87 }
89 static inline void debug_spin_unlock(spinlock_t *lock)
90 {
91 SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
92 SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked");
93 SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
94 SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
95 lock, "wrong CPU");
96 lock->owner = SPINLOCK_OWNER_INIT;
97 lock->owner_cpu = -1;
98 }
100 static void __spin_lock_debug(spinlock_t *lock)
101 {
102 int print_once = 1;
103 u64 i;
105 for (;;) {
106 for (i = 0; i < loops_per_jiffy * HZ; i++) {
107 if (__raw_spin_trylock(&lock->raw_lock))
108 return;
109 __delay(1);
110 }
111 /* lockup suspected: */
112 if (print_once) {
113 print_once = 0;
114 printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
115 "%s/%d, %p\n",
116 raw_smp_processor_id(), current->comm,
117 current->pid, lock);
118 dump_stack();
119 }
120 }
121 }
123 void _raw_spin_lock(spinlock_t *lock)
124 {
125 debug_spin_lock_before(lock);
126 if (unlikely(!__raw_spin_trylock(&lock->raw_lock)))
127 __spin_lock_debug(lock);
128 debug_spin_lock_after(lock);
129 }
131 int _raw_spin_trylock(spinlock_t *lock)
132 {
133 int ret = __raw_spin_trylock(&lock->raw_lock);
135 if (ret)
136 debug_spin_lock_after(lock);
137 #ifndef CONFIG_SMP
138 /*
139 * Must not happen on UP:
140 */
141 SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
142 #endif
143 return ret;
144 }
146 void _raw_spin_unlock(spinlock_t *lock)
147 {
148 debug_spin_unlock(lock);
149 __raw_spin_unlock(&lock->raw_lock);
150 }
152 static void rwlock_bug(rwlock_t *lock, const char *msg)
153 {
154 if (!debug_locks_off())
155 return;
157 printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n",
158 msg, raw_smp_processor_id(), current->comm,
159 current->pid, lock);
160 dump_stack();
161 }
163 #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
165 #if 0 /* __write_lock_debug() can lock up - maybe this can too? */
166 static void __read_lock_debug(rwlock_t *lock)
167 {
168 int print_once = 1;
169 u64 i;
171 for (;;) {
172 for (i = 0; i < loops_per_jiffy * HZ; i++) {
173 if (__raw_read_trylock(&lock->raw_lock))
174 return;
175 __delay(1);
176 }
177 /* lockup suspected: */
178 if (print_once) {
179 print_once = 0;
180 printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, "
181 "%s/%d, %p\n",
182 raw_smp_processor_id(), current->comm,
183 current->pid, lock);
184 dump_stack();
185 }
186 }
187 }
188 #endif
190 void _raw_read_lock(rwlock_t *lock)
191 {
192 RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
193 __raw_read_lock(&lock->raw_lock);
194 }
196 int _raw_read_trylock(rwlock_t *lock)
197 {
198 int ret = __raw_read_trylock(&lock->raw_lock);
200 #ifndef CONFIG_SMP
201 /*
202 * Must not happen on UP:
203 */
204 RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
205 #endif
206 return ret;
207 }
209 void _raw_read_unlock(rwlock_t *lock)
210 {
211 RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
212 __raw_read_unlock(&lock->raw_lock);
213 }
215 static inline void debug_write_lock_before(rwlock_t *lock)
216 {
217 RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
218 RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
219 RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
220 lock, "cpu recursion");
221 }
223 static inline void debug_write_lock_after(rwlock_t *lock)
224 {
225 lock->owner_cpu = raw_smp_processor_id();
226 lock->owner = current;
227 }
229 static inline void debug_write_unlock(rwlock_t *lock)
230 {
231 RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
232 RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
233 RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
234 lock, "wrong CPU");
235 lock->owner = SPINLOCK_OWNER_INIT;
236 lock->owner_cpu = -1;
237 }
239 #if 0 /* This can cause lockups */
240 static void __write_lock_debug(rwlock_t *lock)
241 {
242 int print_once = 1;
243 u64 i;
245 for (;;) {
246 for (i = 0; i < loops_per_jiffy * HZ; i++) {
247 if (__raw_write_trylock(&lock->raw_lock))
248 return;
249 __delay(1);
250 }
251 /* lockup suspected: */
252 if (print_once) {
253 print_once = 0;
254 printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
255 "%s/%d, %p\n",
256 raw_smp_processor_id(), current->comm,
257 current->pid, lock);
258 dump_stack();
259 }
260 }
261 }
262 #endif
264 void _raw_write_lock(rwlock_t *lock)
265 {
266 debug_write_lock_before(lock);
267 __raw_write_lock(&lock->raw_lock);
268 debug_write_lock_after(lock);
269 }
271 int _raw_write_trylock(rwlock_t *lock)
272 {
273 int ret = __raw_write_trylock(&lock->raw_lock);
275 if (ret)
276 debug_write_lock_after(lock);
277 #ifndef CONFIG_SMP
278 /*
279 * Must not happen on UP:
280 */
281 RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
282 #endif
283 return ret;
284 }
286 void _raw_write_unlock(rwlock_t *lock)
287 {
288 debug_write_unlock(lock);
289 __raw_write_unlock(&lock->raw_lock);
290 }