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authorThomas Gleixner <tglx@linutronix.de>2010-02-24 03:54:54 -0500
committerIngo Molnar <mingo@elte.hu>2011-09-13 05:11:59 -0400
commitddb6c9b58a19edcfac93ac670b066c836ff729f1 (patch)
tree70a9ab2dde08671a050424b0d70fa535472e1345 /lib
parent8292c9e15c3b069459794a04f5e2cf0d5665ddc4 (diff)
locking, rwsem: Annotate inner lock as raw
There is no reason to allow the lock protecting rwsems (the ownerless variant) to be preemptible on -rt. Convert it to raw. In mainline this change documents the low level nature of the lock - otherwise there's no functional difference. Lockdep and Sparse checking will work as usual. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib')
-rw-r--r--lib/rwsem-spinlock.c38
-rw-r--r--lib/rwsem.c14
2 files changed, 26 insertions, 26 deletions
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c
index ffc9fc7f3b05..f2393c21fe85 100644
--- a/lib/rwsem-spinlock.c
+++ b/lib/rwsem-spinlock.c
@@ -22,9 +22,9 @@ int rwsem_is_locked(struct rw_semaphore *sem)
22 int ret = 1; 22 int ret = 1;
23 unsigned long flags; 23 unsigned long flags;
24 24
25 if (spin_trylock_irqsave(&sem->wait_lock, flags)) { 25 if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) {
26 ret = (sem->activity != 0); 26 ret = (sem->activity != 0);
27 spin_unlock_irqrestore(&sem->wait_lock, flags); 27 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
28 } 28 }
29 return ret; 29 return ret;
30} 30}
@@ -44,7 +44,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
44 lockdep_init_map(&sem->dep_map, name, key, 0); 44 lockdep_init_map(&sem->dep_map, name, key, 0);
45#endif 45#endif
46 sem->activity = 0; 46 sem->activity = 0;
47 spin_lock_init(&sem->wait_lock); 47 raw_spin_lock_init(&sem->wait_lock);
48 INIT_LIST_HEAD(&sem->wait_list); 48 INIT_LIST_HEAD(&sem->wait_list);
49} 49}
50EXPORT_SYMBOL(__init_rwsem); 50EXPORT_SYMBOL(__init_rwsem);
@@ -145,12 +145,12 @@ void __sched __down_read(struct rw_semaphore *sem)
145 struct task_struct *tsk; 145 struct task_struct *tsk;
146 unsigned long flags; 146 unsigned long flags;
147 147
148 spin_lock_irqsave(&sem->wait_lock, flags); 148 raw_spin_lock_irqsave(&sem->wait_lock, flags);
149 149
150 if (sem->activity >= 0 && list_empty(&sem->wait_list)) { 150 if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
151 /* granted */ 151 /* granted */
152 sem->activity++; 152 sem->activity++;
153 spin_unlock_irqrestore(&sem->wait_lock, flags); 153 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
154 goto out; 154 goto out;
155 } 155 }
156 156
@@ -165,7 +165,7 @@ void __sched __down_read(struct rw_semaphore *sem)
165 list_add_tail(&waiter.list, &sem->wait_list); 165 list_add_tail(&waiter.list, &sem->wait_list);
166 166
167 /* we don't need to touch the semaphore struct anymore */ 167 /* we don't need to touch the semaphore struct anymore */
168 spin_unlock_irqrestore(&sem->wait_lock, flags); 168 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
169 169
170 /* wait to be given the lock */ 170 /* wait to be given the lock */
171 for (;;) { 171 for (;;) {
@@ -189,7 +189,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
189 int ret = 0; 189 int ret = 0;
190 190
191 191
192 spin_lock_irqsave(&sem->wait_lock, flags); 192 raw_spin_lock_irqsave(&sem->wait_lock, flags);
193 193
194 if (sem->activity >= 0 && list_empty(&sem->wait_list)) { 194 if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
195 /* granted */ 195 /* granted */
@@ -197,7 +197,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
197 ret = 1; 197 ret = 1;
198 } 198 }
199 199
200 spin_unlock_irqrestore(&sem->wait_lock, flags); 200 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
201 201
202 return ret; 202 return ret;
203} 203}
@@ -212,12 +212,12 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
212 struct task_struct *tsk; 212 struct task_struct *tsk;
213 unsigned long flags; 213 unsigned long flags;
214 214
215 spin_lock_irqsave(&sem->wait_lock, flags); 215 raw_spin_lock_irqsave(&sem->wait_lock, flags);
216 216
217 if (sem->activity == 0 && list_empty(&sem->wait_list)) { 217 if (sem->activity == 0 && list_empty(&sem->wait_list)) {
218 /* granted */ 218 /* granted */
219 sem->activity = -1; 219 sem->activity = -1;
220 spin_unlock_irqrestore(&sem->wait_lock, flags); 220 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
221 goto out; 221 goto out;
222 } 222 }
223 223
@@ -232,7 +232,7 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
232 list_add_tail(&waiter.list, &sem->wait_list); 232 list_add_tail(&waiter.list, &sem->wait_list);
233 233
234 /* we don't need to touch the semaphore struct anymore */ 234 /* we don't need to touch the semaphore struct anymore */
235 spin_unlock_irqrestore(&sem->wait_lock, flags); 235 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
236 236
237 /* wait to be given the lock */ 237 /* wait to be given the lock */
238 for (;;) { 238 for (;;) {
@@ -260,7 +260,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
260 unsigned long flags; 260 unsigned long flags;
261 int ret = 0; 261 int ret = 0;
262 262
263 spin_lock_irqsave(&sem->wait_lock, flags); 263 raw_spin_lock_irqsave(&sem->wait_lock, flags);
264 264
265 if (sem->activity == 0 && list_empty(&sem->wait_list)) { 265 if (sem->activity == 0 && list_empty(&sem->wait_list)) {
266 /* granted */ 266 /* granted */
@@ -268,7 +268,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
268 ret = 1; 268 ret = 1;
269 } 269 }
270 270
271 spin_unlock_irqrestore(&sem->wait_lock, flags); 271 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
272 272
273 return ret; 273 return ret;
274} 274}
@@ -280,12 +280,12 @@ void __up_read(struct rw_semaphore *sem)
280{ 280{
281 unsigned long flags; 281 unsigned long flags;
282 282
283 spin_lock_irqsave(&sem->wait_lock, flags); 283 raw_spin_lock_irqsave(&sem->wait_lock, flags);
284 284
285 if (--sem->activity == 0 && !list_empty(&sem->wait_list)) 285 if (--sem->activity == 0 && !list_empty(&sem->wait_list))
286 sem = __rwsem_wake_one_writer(sem); 286 sem = __rwsem_wake_one_writer(sem);
287 287
288 spin_unlock_irqrestore(&sem->wait_lock, flags); 288 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
289} 289}
290 290
291/* 291/*
@@ -295,13 +295,13 @@ void __up_write(struct rw_semaphore *sem)
295{ 295{
296 unsigned long flags; 296 unsigned long flags;
297 297
298 spin_lock_irqsave(&sem->wait_lock, flags); 298 raw_spin_lock_irqsave(&sem->wait_lock, flags);
299 299
300 sem->activity = 0; 300 sem->activity = 0;
301 if (!list_empty(&sem->wait_list)) 301 if (!list_empty(&sem->wait_list))
302 sem = __rwsem_do_wake(sem, 1); 302 sem = __rwsem_do_wake(sem, 1);
303 303
304 spin_unlock_irqrestore(&sem->wait_lock, flags); 304 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
305} 305}
306 306
307/* 307/*
@@ -312,12 +312,12 @@ void __downgrade_write(struct rw_semaphore *sem)
312{ 312{
313 unsigned long flags; 313 unsigned long flags;
314 314
315 spin_lock_irqsave(&sem->wait_lock, flags); 315 raw_spin_lock_irqsave(&sem->wait_lock, flags);
316 316
317 sem->activity = 1; 317 sem->activity = 1;
318 if (!list_empty(&sem->wait_list)) 318 if (!list_empty(&sem->wait_list))
319 sem = __rwsem_do_wake(sem, 0); 319 sem = __rwsem_do_wake(sem, 0);
320 320
321 spin_unlock_irqrestore(&sem->wait_lock, flags); 321 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
322} 322}
323 323
diff --git a/lib/rwsem.c b/lib/rwsem.c
index aa7c3052261f..410aa1189b13 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -22,7 +22,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
22 lockdep_init_map(&sem->dep_map, name, key, 0); 22 lockdep_init_map(&sem->dep_map, name, key, 0);
23#endif 23#endif
24 sem->count = RWSEM_UNLOCKED_VALUE; 24 sem->count = RWSEM_UNLOCKED_VALUE;
25 spin_lock_init(&sem->wait_lock); 25 raw_spin_lock_init(&sem->wait_lock);
26 INIT_LIST_HEAD(&sem->wait_list); 26 INIT_LIST_HEAD(&sem->wait_list);
27} 27}
28 28
@@ -180,7 +180,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
180 set_task_state(tsk, TASK_UNINTERRUPTIBLE); 180 set_task_state(tsk, TASK_UNINTERRUPTIBLE);
181 181
182 /* set up my own style of waitqueue */ 182 /* set up my own style of waitqueue */
183 spin_lock_irq(&sem->wait_lock); 183 raw_spin_lock_irq(&sem->wait_lock);
184 waiter.task = tsk; 184 waiter.task = tsk;
185 waiter.flags = flags; 185 waiter.flags = flags;
186 get_task_struct(tsk); 186 get_task_struct(tsk);
@@ -204,7 +204,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
204 adjustment == -RWSEM_ACTIVE_WRITE_BIAS) 204 adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
205 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED); 205 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
206 206
207 spin_unlock_irq(&sem->wait_lock); 207 raw_spin_unlock_irq(&sem->wait_lock);
208 208
209 /* wait to be given the lock */ 209 /* wait to be given the lock */
210 for (;;) { 210 for (;;) {
@@ -245,13 +245,13 @@ struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
245{ 245{
246 unsigned long flags; 246 unsigned long flags;
247 247
248 spin_lock_irqsave(&sem->wait_lock, flags); 248 raw_spin_lock_irqsave(&sem->wait_lock, flags);
249 249
250 /* do nothing if list empty */ 250 /* do nothing if list empty */
251 if (!list_empty(&sem->wait_list)) 251 if (!list_empty(&sem->wait_list))
252 sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY); 252 sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
253 253
254 spin_unlock_irqrestore(&sem->wait_lock, flags); 254 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
255 255
256 return sem; 256 return sem;
257} 257}
@@ -265,13 +265,13 @@ struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
265{ 265{
266 unsigned long flags; 266 unsigned long flags;
267 267
268 spin_lock_irqsave(&sem->wait_lock, flags); 268 raw_spin_lock_irqsave(&sem->wait_lock, flags);
269 269
270 /* do nothing if list empty */ 270 /* do nothing if list empty */
271 if (!list_empty(&sem->wait_list)) 271 if (!list_empty(&sem->wait_list))
272 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED); 272 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
273 273
274 spin_unlock_irqrestore(&sem->wait_lock, flags); 274 raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
275 275
276 return sem; 276 return sem;
277} 277}