Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/timer.c | |
3 | * | |
8524070b | 4 | * Kernel internal timers, basic process system calls |
1da177e4 LT |
5 | * |
6 | * Copyright (C) 1991, 1992 Linus Torvalds | |
7 | * | |
8 | * 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better. | |
9 | * | |
10 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 | |
11 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
12 | * 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to | |
13 | * serialize accesses to xtime/lost_ticks). | |
14 | * Copyright (C) 1998 Andrea Arcangeli | |
15 | * 1999-03-10 Improved NTP compatibility by Ulrich Windl | |
16 | * 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love | |
17 | * 2000-10-05 Implemented scalable SMP per-CPU timer handling. | |
18 | * Copyright (C) 2000, 2001, 2002 Ingo Molnar | |
19 | * Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar | |
20 | */ | |
21 | ||
22 | #include <linux/kernel_stat.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/percpu.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/swap.h> | |
b488893a | 29 | #include <linux/pid_namespace.h> |
1da177e4 LT |
30 | #include <linux/notifier.h> |
31 | #include <linux/thread_info.h> | |
32 | #include <linux/time.h> | |
33 | #include <linux/jiffies.h> | |
34 | #include <linux/posix-timers.h> | |
35 | #include <linux/cpu.h> | |
36 | #include <linux/syscalls.h> | |
97a41e26 | 37 | #include <linux/delay.h> |
79bf2bb3 | 38 | #include <linux/tick.h> |
82f67cd9 | 39 | #include <linux/kallsyms.h> |
cdd6c482 | 40 | #include <linux/perf_event.h> |
eea08f32 | 41 | #include <linux/sched.h> |
5a0e3ad6 | 42 | #include <linux/slab.h> |
1da177e4 LT |
43 | |
44 | #include <asm/uaccess.h> | |
45 | #include <asm/unistd.h> | |
46 | #include <asm/div64.h> | |
47 | #include <asm/timex.h> | |
48 | #include <asm/io.h> | |
49 | ||
2b022e3d XG |
50 | #define CREATE_TRACE_POINTS |
51 | #include <trace/events/timer.h> | |
52 | ||
ecea8d19 TG |
53 | u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; |
54 | ||
55 | EXPORT_SYMBOL(jiffies_64); | |
56 | ||
1da177e4 LT |
57 | /* |
58 | * per-CPU timer vector definitions: | |
59 | */ | |
1da177e4 LT |
60 | #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6) |
61 | #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) | |
62 | #define TVN_SIZE (1 << TVN_BITS) | |
63 | #define TVR_SIZE (1 << TVR_BITS) | |
64 | #define TVN_MASK (TVN_SIZE - 1) | |
65 | #define TVR_MASK (TVR_SIZE - 1) | |
66 | ||
a6fa8e5a | 67 | struct tvec { |
1da177e4 | 68 | struct list_head vec[TVN_SIZE]; |
a6fa8e5a | 69 | }; |
1da177e4 | 70 | |
a6fa8e5a | 71 | struct tvec_root { |
1da177e4 | 72 | struct list_head vec[TVR_SIZE]; |
a6fa8e5a | 73 | }; |
1da177e4 | 74 | |
a6fa8e5a | 75 | struct tvec_base { |
3691c519 ON |
76 | spinlock_t lock; |
77 | struct timer_list *running_timer; | |
1da177e4 | 78 | unsigned long timer_jiffies; |
97fd9ed4 | 79 | unsigned long next_timer; |
a6fa8e5a PM |
80 | struct tvec_root tv1; |
81 | struct tvec tv2; | |
82 | struct tvec tv3; | |
83 | struct tvec tv4; | |
84 | struct tvec tv5; | |
6e453a67 | 85 | } ____cacheline_aligned; |
1da177e4 | 86 | |
a6fa8e5a | 87 | struct tvec_base boot_tvec_bases; |
3691c519 | 88 | EXPORT_SYMBOL(boot_tvec_bases); |
a6fa8e5a | 89 | static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; |
1da177e4 | 90 | |
6e453a67 | 91 | /* |
a6fa8e5a | 92 | * Note that all tvec_bases are 2 byte aligned and lower bit of |
6e453a67 VP |
93 | * base in timer_list is guaranteed to be zero. Use the LSB for |
94 | * the new flag to indicate whether the timer is deferrable | |
95 | */ | |
96 | #define TBASE_DEFERRABLE_FLAG (0x1) | |
97 | ||
98 | /* Functions below help us manage 'deferrable' flag */ | |
a6fa8e5a | 99 | static inline unsigned int tbase_get_deferrable(struct tvec_base *base) |
6e453a67 | 100 | { |
e9910846 | 101 | return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); |
6e453a67 VP |
102 | } |
103 | ||
a6fa8e5a | 104 | static inline struct tvec_base *tbase_get_base(struct tvec_base *base) |
6e453a67 | 105 | { |
a6fa8e5a | 106 | return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG)); |
6e453a67 VP |
107 | } |
108 | ||
109 | static inline void timer_set_deferrable(struct timer_list *timer) | |
110 | { | |
a6fa8e5a | 111 | timer->base = ((struct tvec_base *)((unsigned long)(timer->base) | |
6819457d | 112 | TBASE_DEFERRABLE_FLAG)); |
6e453a67 VP |
113 | } |
114 | ||
115 | static inline void | |
a6fa8e5a | 116 | timer_set_base(struct timer_list *timer, struct tvec_base *new_base) |
6e453a67 | 117 | { |
a6fa8e5a | 118 | timer->base = (struct tvec_base *)((unsigned long)(new_base) | |
6819457d | 119 | tbase_get_deferrable(timer->base)); |
6e453a67 VP |
120 | } |
121 | ||
9c133c46 AS |
122 | static unsigned long round_jiffies_common(unsigned long j, int cpu, |
123 | bool force_up) | |
4c36a5de AV |
124 | { |
125 | int rem; | |
126 | unsigned long original = j; | |
127 | ||
128 | /* | |
129 | * We don't want all cpus firing their timers at once hitting the | |
130 | * same lock or cachelines, so we skew each extra cpu with an extra | |
131 | * 3 jiffies. This 3 jiffies came originally from the mm/ code which | |
132 | * already did this. | |
133 | * The skew is done by adding 3*cpunr, then round, then subtract this | |
134 | * extra offset again. | |
135 | */ | |
136 | j += cpu * 3; | |
137 | ||
138 | rem = j % HZ; | |
139 | ||
140 | /* | |
141 | * If the target jiffie is just after a whole second (which can happen | |
142 | * due to delays of the timer irq, long irq off times etc etc) then | |
143 | * we should round down to the whole second, not up. Use 1/4th second | |
144 | * as cutoff for this rounding as an extreme upper bound for this. | |
9c133c46 | 145 | * But never round down if @force_up is set. |
4c36a5de | 146 | */ |
9c133c46 | 147 | if (rem < HZ/4 && !force_up) /* round down */ |
4c36a5de AV |
148 | j = j - rem; |
149 | else /* round up */ | |
150 | j = j - rem + HZ; | |
151 | ||
152 | /* now that we have rounded, subtract the extra skew again */ | |
153 | j -= cpu * 3; | |
154 | ||
155 | if (j <= jiffies) /* rounding ate our timeout entirely; */ | |
156 | return original; | |
157 | return j; | |
158 | } | |
9c133c46 AS |
159 | |
160 | /** | |
161 | * __round_jiffies - function to round jiffies to a full second | |
162 | * @j: the time in (absolute) jiffies that should be rounded | |
163 | * @cpu: the processor number on which the timeout will happen | |
164 | * | |
165 | * __round_jiffies() rounds an absolute time in the future (in jiffies) | |
166 | * up or down to (approximately) full seconds. This is useful for timers | |
167 | * for which the exact time they fire does not matter too much, as long as | |
168 | * they fire approximately every X seconds. | |
169 | * | |
170 | * By rounding these timers to whole seconds, all such timers will fire | |
171 | * at the same time, rather than at various times spread out. The goal | |
172 | * of this is to have the CPU wake up less, which saves power. | |
173 | * | |
174 | * The exact rounding is skewed for each processor to avoid all | |
175 | * processors firing at the exact same time, which could lead | |
176 | * to lock contention or spurious cache line bouncing. | |
177 | * | |
178 | * The return value is the rounded version of the @j parameter. | |
179 | */ | |
180 | unsigned long __round_jiffies(unsigned long j, int cpu) | |
181 | { | |
182 | return round_jiffies_common(j, cpu, false); | |
183 | } | |
4c36a5de AV |
184 | EXPORT_SYMBOL_GPL(__round_jiffies); |
185 | ||
186 | /** | |
187 | * __round_jiffies_relative - function to round jiffies to a full second | |
188 | * @j: the time in (relative) jiffies that should be rounded | |
189 | * @cpu: the processor number on which the timeout will happen | |
190 | * | |
72fd4a35 | 191 | * __round_jiffies_relative() rounds a time delta in the future (in jiffies) |
4c36a5de AV |
192 | * up or down to (approximately) full seconds. This is useful for timers |
193 | * for which the exact time they fire does not matter too much, as long as | |
194 | * they fire approximately every X seconds. | |
195 | * | |
196 | * By rounding these timers to whole seconds, all such timers will fire | |
197 | * at the same time, rather than at various times spread out. The goal | |
198 | * of this is to have the CPU wake up less, which saves power. | |
199 | * | |
200 | * The exact rounding is skewed for each processor to avoid all | |
201 | * processors firing at the exact same time, which could lead | |
202 | * to lock contention or spurious cache line bouncing. | |
203 | * | |
72fd4a35 | 204 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
205 | */ |
206 | unsigned long __round_jiffies_relative(unsigned long j, int cpu) | |
207 | { | |
9c133c46 AS |
208 | unsigned long j0 = jiffies; |
209 | ||
210 | /* Use j0 because jiffies might change while we run */ | |
211 | return round_jiffies_common(j + j0, cpu, false) - j0; | |
4c36a5de AV |
212 | } |
213 | EXPORT_SYMBOL_GPL(__round_jiffies_relative); | |
214 | ||
215 | /** | |
216 | * round_jiffies - function to round jiffies to a full second | |
217 | * @j: the time in (absolute) jiffies that should be rounded | |
218 | * | |
72fd4a35 | 219 | * round_jiffies() rounds an absolute time in the future (in jiffies) |
4c36a5de AV |
220 | * up or down to (approximately) full seconds. This is useful for timers |
221 | * for which the exact time they fire does not matter too much, as long as | |
222 | * they fire approximately every X seconds. | |
223 | * | |
224 | * By rounding these timers to whole seconds, all such timers will fire | |
225 | * at the same time, rather than at various times spread out. The goal | |
226 | * of this is to have the CPU wake up less, which saves power. | |
227 | * | |
72fd4a35 | 228 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
229 | */ |
230 | unsigned long round_jiffies(unsigned long j) | |
231 | { | |
9c133c46 | 232 | return round_jiffies_common(j, raw_smp_processor_id(), false); |
4c36a5de AV |
233 | } |
234 | EXPORT_SYMBOL_GPL(round_jiffies); | |
235 | ||
236 | /** | |
237 | * round_jiffies_relative - function to round jiffies to a full second | |
238 | * @j: the time in (relative) jiffies that should be rounded | |
239 | * | |
72fd4a35 | 240 | * round_jiffies_relative() rounds a time delta in the future (in jiffies) |
4c36a5de AV |
241 | * up or down to (approximately) full seconds. This is useful for timers |
242 | * for which the exact time they fire does not matter too much, as long as | |
243 | * they fire approximately every X seconds. | |
244 | * | |
245 | * By rounding these timers to whole seconds, all such timers will fire | |
246 | * at the same time, rather than at various times spread out. The goal | |
247 | * of this is to have the CPU wake up less, which saves power. | |
248 | * | |
72fd4a35 | 249 | * The return value is the rounded version of the @j parameter. |
4c36a5de AV |
250 | */ |
251 | unsigned long round_jiffies_relative(unsigned long j) | |
252 | { | |
253 | return __round_jiffies_relative(j, raw_smp_processor_id()); | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(round_jiffies_relative); | |
256 | ||
9c133c46 AS |
257 | /** |
258 | * __round_jiffies_up - function to round jiffies up to a full second | |
259 | * @j: the time in (absolute) jiffies that should be rounded | |
260 | * @cpu: the processor number on which the timeout will happen | |
261 | * | |
262 | * This is the same as __round_jiffies() except that it will never | |
263 | * round down. This is useful for timeouts for which the exact time | |
264 | * of firing does not matter too much, as long as they don't fire too | |
265 | * early. | |
266 | */ | |
267 | unsigned long __round_jiffies_up(unsigned long j, int cpu) | |
268 | { | |
269 | return round_jiffies_common(j, cpu, true); | |
270 | } | |
271 | EXPORT_SYMBOL_GPL(__round_jiffies_up); | |
272 | ||
273 | /** | |
274 | * __round_jiffies_up_relative - function to round jiffies up to a full second | |
275 | * @j: the time in (relative) jiffies that should be rounded | |
276 | * @cpu: the processor number on which the timeout will happen | |
277 | * | |
278 | * This is the same as __round_jiffies_relative() except that it will never | |
279 | * round down. This is useful for timeouts for which the exact time | |
280 | * of firing does not matter too much, as long as they don't fire too | |
281 | * early. | |
282 | */ | |
283 | unsigned long __round_jiffies_up_relative(unsigned long j, int cpu) | |
284 | { | |
285 | unsigned long j0 = jiffies; | |
286 | ||
287 | /* Use j0 because jiffies might change while we run */ | |
288 | return round_jiffies_common(j + j0, cpu, true) - j0; | |
289 | } | |
290 | EXPORT_SYMBOL_GPL(__round_jiffies_up_relative); | |
291 | ||
292 | /** | |
293 | * round_jiffies_up - function to round jiffies up to a full second | |
294 | * @j: the time in (absolute) jiffies that should be rounded | |
295 | * | |
296 | * This is the same as round_jiffies() except that it will never | |
297 | * round down. This is useful for timeouts for which the exact time | |
298 | * of firing does not matter too much, as long as they don't fire too | |
299 | * early. | |
300 | */ | |
301 | unsigned long round_jiffies_up(unsigned long j) | |
302 | { | |
303 | return round_jiffies_common(j, raw_smp_processor_id(), true); | |
304 | } | |
305 | EXPORT_SYMBOL_GPL(round_jiffies_up); | |
306 | ||
307 | /** | |
308 | * round_jiffies_up_relative - function to round jiffies up to a full second | |
309 | * @j: the time in (relative) jiffies that should be rounded | |
310 | * | |
311 | * This is the same as round_jiffies_relative() except that it will never | |
312 | * round down. This is useful for timeouts for which the exact time | |
313 | * of firing does not matter too much, as long as they don't fire too | |
314 | * early. | |
315 | */ | |
316 | unsigned long round_jiffies_up_relative(unsigned long j) | |
317 | { | |
318 | return __round_jiffies_up_relative(j, raw_smp_processor_id()); | |
319 | } | |
320 | EXPORT_SYMBOL_GPL(round_jiffies_up_relative); | |
321 | ||
4c36a5de | 322 | |
a6fa8e5a | 323 | static inline void set_running_timer(struct tvec_base *base, |
1da177e4 LT |
324 | struct timer_list *timer) |
325 | { | |
326 | #ifdef CONFIG_SMP | |
3691c519 | 327 | base->running_timer = timer; |
1da177e4 LT |
328 | #endif |
329 | } | |
330 | ||
a6fa8e5a | 331 | static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) |
1da177e4 LT |
332 | { |
333 | unsigned long expires = timer->expires; | |
334 | unsigned long idx = expires - base->timer_jiffies; | |
335 | struct list_head *vec; | |
336 | ||
337 | if (idx < TVR_SIZE) { | |
338 | int i = expires & TVR_MASK; | |
339 | vec = base->tv1.vec + i; | |
340 | } else if (idx < 1 << (TVR_BITS + TVN_BITS)) { | |
341 | int i = (expires >> TVR_BITS) & TVN_MASK; | |
342 | vec = base->tv2.vec + i; | |
343 | } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) { | |
344 | int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK; | |
345 | vec = base->tv3.vec + i; | |
346 | } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) { | |
347 | int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK; | |
348 | vec = base->tv4.vec + i; | |
349 | } else if ((signed long) idx < 0) { | |
350 | /* | |
351 | * Can happen if you add a timer with expires == jiffies, | |
352 | * or you set a timer to go off in the past | |
353 | */ | |
354 | vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK); | |
355 | } else { | |
356 | int i; | |
357 | /* If the timeout is larger than 0xffffffff on 64-bit | |
358 | * architectures then we use the maximum timeout: | |
359 | */ | |
360 | if (idx > 0xffffffffUL) { | |
361 | idx = 0xffffffffUL; | |
362 | expires = idx + base->timer_jiffies; | |
363 | } | |
364 | i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK; | |
365 | vec = base->tv5.vec + i; | |
366 | } | |
367 | /* | |
368 | * Timers are FIFO: | |
369 | */ | |
370 | list_add_tail(&timer->entry, vec); | |
371 | } | |
372 | ||
82f67cd9 IM |
373 | #ifdef CONFIG_TIMER_STATS |
374 | void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) | |
375 | { | |
376 | if (timer->start_site) | |
377 | return; | |
378 | ||
379 | timer->start_site = addr; | |
380 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); | |
381 | timer->start_pid = current->pid; | |
382 | } | |
c5c061b8 VP |
383 | |
384 | static void timer_stats_account_timer(struct timer_list *timer) | |
385 | { | |
386 | unsigned int flag = 0; | |
387 | ||
507e1231 HC |
388 | if (likely(!timer->start_site)) |
389 | return; | |
c5c061b8 VP |
390 | if (unlikely(tbase_get_deferrable(timer->base))) |
391 | flag |= TIMER_STATS_FLAG_DEFERRABLE; | |
392 | ||
393 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, | |
394 | timer->function, timer->start_comm, flag); | |
395 | } | |
396 | ||
397 | #else | |
398 | static void timer_stats_account_timer(struct timer_list *timer) {} | |
82f67cd9 IM |
399 | #endif |
400 | ||
c6f3a97f TG |
401 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
402 | ||
403 | static struct debug_obj_descr timer_debug_descr; | |
404 | ||
405 | /* | |
406 | * fixup_init is called when: | |
407 | * - an active object is initialized | |
55c888d6 | 408 | */ |
c6f3a97f TG |
409 | static int timer_fixup_init(void *addr, enum debug_obj_state state) |
410 | { | |
411 | struct timer_list *timer = addr; | |
412 | ||
413 | switch (state) { | |
414 | case ODEBUG_STATE_ACTIVE: | |
415 | del_timer_sync(timer); | |
416 | debug_object_init(timer, &timer_debug_descr); | |
417 | return 1; | |
418 | default: | |
419 | return 0; | |
420 | } | |
421 | } | |
422 | ||
423 | /* | |
424 | * fixup_activate is called when: | |
425 | * - an active object is activated | |
426 | * - an unknown object is activated (might be a statically initialized object) | |
427 | */ | |
428 | static int timer_fixup_activate(void *addr, enum debug_obj_state state) | |
429 | { | |
430 | struct timer_list *timer = addr; | |
431 | ||
432 | switch (state) { | |
433 | ||
434 | case ODEBUG_STATE_NOTAVAILABLE: | |
435 | /* | |
436 | * This is not really a fixup. The timer was | |
437 | * statically initialized. We just make sure that it | |
438 | * is tracked in the object tracker. | |
439 | */ | |
440 | if (timer->entry.next == NULL && | |
441 | timer->entry.prev == TIMER_ENTRY_STATIC) { | |
442 | debug_object_init(timer, &timer_debug_descr); | |
443 | debug_object_activate(timer, &timer_debug_descr); | |
444 | return 0; | |
445 | } else { | |
446 | WARN_ON_ONCE(1); | |
447 | } | |
448 | return 0; | |
449 | ||
450 | case ODEBUG_STATE_ACTIVE: | |
451 | WARN_ON(1); | |
452 | ||
453 | default: | |
454 | return 0; | |
455 | } | |
456 | } | |
457 | ||
458 | /* | |
459 | * fixup_free is called when: | |
460 | * - an active object is freed | |
461 | */ | |
462 | static int timer_fixup_free(void *addr, enum debug_obj_state state) | |
463 | { | |
464 | struct timer_list *timer = addr; | |
465 | ||
466 | switch (state) { | |
467 | case ODEBUG_STATE_ACTIVE: | |
468 | del_timer_sync(timer); | |
469 | debug_object_free(timer, &timer_debug_descr); | |
470 | return 1; | |
471 | default: | |
472 | return 0; | |
473 | } | |
474 | } | |
475 | ||
476 | static struct debug_obj_descr timer_debug_descr = { | |
477 | .name = "timer_list", | |
478 | .fixup_init = timer_fixup_init, | |
479 | .fixup_activate = timer_fixup_activate, | |
480 | .fixup_free = timer_fixup_free, | |
481 | }; | |
482 | ||
483 | static inline void debug_timer_init(struct timer_list *timer) | |
484 | { | |
485 | debug_object_init(timer, &timer_debug_descr); | |
486 | } | |
487 | ||
488 | static inline void debug_timer_activate(struct timer_list *timer) | |
489 | { | |
490 | debug_object_activate(timer, &timer_debug_descr); | |
491 | } | |
492 | ||
493 | static inline void debug_timer_deactivate(struct timer_list *timer) | |
494 | { | |
495 | debug_object_deactivate(timer, &timer_debug_descr); | |
496 | } | |
497 | ||
498 | static inline void debug_timer_free(struct timer_list *timer) | |
499 | { | |
500 | debug_object_free(timer, &timer_debug_descr); | |
501 | } | |
502 | ||
6f2b9b9a JB |
503 | static void __init_timer(struct timer_list *timer, |
504 | const char *name, | |
505 | struct lock_class_key *key); | |
c6f3a97f | 506 | |
6f2b9b9a JB |
507 | void init_timer_on_stack_key(struct timer_list *timer, |
508 | const char *name, | |
509 | struct lock_class_key *key) | |
c6f3a97f TG |
510 | { |
511 | debug_object_init_on_stack(timer, &timer_debug_descr); | |
6f2b9b9a | 512 | __init_timer(timer, name, key); |
c6f3a97f | 513 | } |
6f2b9b9a | 514 | EXPORT_SYMBOL_GPL(init_timer_on_stack_key); |
c6f3a97f TG |
515 | |
516 | void destroy_timer_on_stack(struct timer_list *timer) | |
517 | { | |
518 | debug_object_free(timer, &timer_debug_descr); | |
519 | } | |
520 | EXPORT_SYMBOL_GPL(destroy_timer_on_stack); | |
521 | ||
522 | #else | |
523 | static inline void debug_timer_init(struct timer_list *timer) { } | |
524 | static inline void debug_timer_activate(struct timer_list *timer) { } | |
525 | static inline void debug_timer_deactivate(struct timer_list *timer) { } | |
526 | #endif | |
527 | ||
2b022e3d XG |
528 | static inline void debug_init(struct timer_list *timer) |
529 | { | |
530 | debug_timer_init(timer); | |
531 | trace_timer_init(timer); | |
532 | } | |
533 | ||
534 | static inline void | |
535 | debug_activate(struct timer_list *timer, unsigned long expires) | |
536 | { | |
537 | debug_timer_activate(timer); | |
538 | trace_timer_start(timer, expires); | |
539 | } | |
540 | ||
541 | static inline void debug_deactivate(struct timer_list *timer) | |
542 | { | |
543 | debug_timer_deactivate(timer); | |
544 | trace_timer_cancel(timer); | |
545 | } | |
546 | ||
6f2b9b9a JB |
547 | static void __init_timer(struct timer_list *timer, |
548 | const char *name, | |
549 | struct lock_class_key *key) | |
55c888d6 ON |
550 | { |
551 | timer->entry.next = NULL; | |
bfe5d834 | 552 | timer->base = __raw_get_cpu_var(tvec_bases); |
82f67cd9 IM |
553 | #ifdef CONFIG_TIMER_STATS |
554 | timer->start_site = NULL; | |
555 | timer->start_pid = -1; | |
556 | memset(timer->start_comm, 0, TASK_COMM_LEN); | |
557 | #endif | |
6f2b9b9a | 558 | lockdep_init_map(&timer->lockdep_map, name, key, 0); |
55c888d6 | 559 | } |
c6f3a97f TG |
560 | |
561 | /** | |
633fe795 | 562 | * init_timer_key - initialize a timer |
c6f3a97f | 563 | * @timer: the timer to be initialized |
633fe795 RD |
564 | * @name: name of the timer |
565 | * @key: lockdep class key of the fake lock used for tracking timer | |
566 | * sync lock dependencies | |
c6f3a97f | 567 | * |
633fe795 | 568 | * init_timer_key() must be done to a timer prior calling *any* of the |
c6f3a97f TG |
569 | * other timer functions. |
570 | */ | |
6f2b9b9a JB |
571 | void init_timer_key(struct timer_list *timer, |
572 | const char *name, | |
573 | struct lock_class_key *key) | |
c6f3a97f | 574 | { |
2b022e3d | 575 | debug_init(timer); |
6f2b9b9a | 576 | __init_timer(timer, name, key); |
c6f3a97f | 577 | } |
6f2b9b9a | 578 | EXPORT_SYMBOL(init_timer_key); |
55c888d6 | 579 | |
6f2b9b9a JB |
580 | void init_timer_deferrable_key(struct timer_list *timer, |
581 | const char *name, | |
582 | struct lock_class_key *key) | |
6e453a67 | 583 | { |
6f2b9b9a | 584 | init_timer_key(timer, name, key); |
6e453a67 VP |
585 | timer_set_deferrable(timer); |
586 | } | |
6f2b9b9a | 587 | EXPORT_SYMBOL(init_timer_deferrable_key); |
6e453a67 | 588 | |
55c888d6 | 589 | static inline void detach_timer(struct timer_list *timer, |
82f67cd9 | 590 | int clear_pending) |
55c888d6 ON |
591 | { |
592 | struct list_head *entry = &timer->entry; | |
593 | ||
2b022e3d | 594 | debug_deactivate(timer); |
c6f3a97f | 595 | |
55c888d6 ON |
596 | __list_del(entry->prev, entry->next); |
597 | if (clear_pending) | |
598 | entry->next = NULL; | |
599 | entry->prev = LIST_POISON2; | |
600 | } | |
601 | ||
602 | /* | |
3691c519 | 603 | * We are using hashed locking: holding per_cpu(tvec_bases).lock |
55c888d6 ON |
604 | * means that all timers which are tied to this base via timer->base are |
605 | * locked, and the base itself is locked too. | |
606 | * | |
607 | * So __run_timers/migrate_timers can safely modify all timers which could | |
608 | * be found on ->tvX lists. | |
609 | * | |
610 | * When the timer's base is locked, and the timer removed from list, it is | |
611 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
612 | * locked. | |
613 | */ | |
a6fa8e5a | 614 | static struct tvec_base *lock_timer_base(struct timer_list *timer, |
55c888d6 | 615 | unsigned long *flags) |
89e7e374 | 616 | __acquires(timer->base->lock) |
55c888d6 | 617 | { |
a6fa8e5a | 618 | struct tvec_base *base; |
55c888d6 ON |
619 | |
620 | for (;;) { | |
a6fa8e5a | 621 | struct tvec_base *prelock_base = timer->base; |
6e453a67 | 622 | base = tbase_get_base(prelock_base); |
55c888d6 ON |
623 | if (likely(base != NULL)) { |
624 | spin_lock_irqsave(&base->lock, *flags); | |
6e453a67 | 625 | if (likely(prelock_base == timer->base)) |
55c888d6 ON |
626 | return base; |
627 | /* The timer has migrated to another CPU */ | |
628 | spin_unlock_irqrestore(&base->lock, *flags); | |
629 | } | |
630 | cpu_relax(); | |
631 | } | |
632 | } | |
633 | ||
74019224 | 634 | static inline int |
597d0275 AB |
635 | __mod_timer(struct timer_list *timer, unsigned long expires, |
636 | bool pending_only, int pinned) | |
1da177e4 | 637 | { |
a6fa8e5a | 638 | struct tvec_base *base, *new_base; |
1da177e4 | 639 | unsigned long flags; |
eea08f32 | 640 | int ret = 0 , cpu; |
1da177e4 | 641 | |
82f67cd9 | 642 | timer_stats_timer_set_start_info(timer); |
1da177e4 | 643 | BUG_ON(!timer->function); |
1da177e4 | 644 | |
55c888d6 ON |
645 | base = lock_timer_base(timer, &flags); |
646 | ||
647 | if (timer_pending(timer)) { | |
648 | detach_timer(timer, 0); | |
97fd9ed4 MS |
649 | if (timer->expires == base->next_timer && |
650 | !tbase_get_deferrable(timer->base)) | |
651 | base->next_timer = base->timer_jiffies; | |
55c888d6 | 652 | ret = 1; |
74019224 IM |
653 | } else { |
654 | if (pending_only) | |
655 | goto out_unlock; | |
55c888d6 ON |
656 | } |
657 | ||
2b022e3d | 658 | debug_activate(timer, expires); |
c6f3a97f | 659 | |
eea08f32 AB |
660 | cpu = smp_processor_id(); |
661 | ||
662 | #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) | |
663 | if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) { | |
664 | int preferred_cpu = get_nohz_load_balancer(); | |
665 | ||
666 | if (preferred_cpu >= 0) | |
667 | cpu = preferred_cpu; | |
668 | } | |
669 | #endif | |
670 | new_base = per_cpu(tvec_bases, cpu); | |
671 | ||
3691c519 | 672 | if (base != new_base) { |
1da177e4 | 673 | /* |
55c888d6 ON |
674 | * We are trying to schedule the timer on the local CPU. |
675 | * However we can't change timer's base while it is running, | |
676 | * otherwise del_timer_sync() can't detect that the timer's | |
677 | * handler yet has not finished. This also guarantees that | |
678 | * the timer is serialized wrt itself. | |
1da177e4 | 679 | */ |
a2c348fe | 680 | if (likely(base->running_timer != timer)) { |
55c888d6 | 681 | /* See the comment in lock_timer_base() */ |
6e453a67 | 682 | timer_set_base(timer, NULL); |
55c888d6 | 683 | spin_unlock(&base->lock); |
a2c348fe ON |
684 | base = new_base; |
685 | spin_lock(&base->lock); | |
6e453a67 | 686 | timer_set_base(timer, base); |
1da177e4 LT |
687 | } |
688 | } | |
689 | ||
1da177e4 | 690 | timer->expires = expires; |
97fd9ed4 MS |
691 | if (time_before(timer->expires, base->next_timer) && |
692 | !tbase_get_deferrable(timer->base)) | |
693 | base->next_timer = timer->expires; | |
a2c348fe | 694 | internal_add_timer(base, timer); |
74019224 IM |
695 | |
696 | out_unlock: | |
a2c348fe | 697 | spin_unlock_irqrestore(&base->lock, flags); |
1da177e4 LT |
698 | |
699 | return ret; | |
700 | } | |
701 | ||
2aae4a10 | 702 | /** |
74019224 IM |
703 | * mod_timer_pending - modify a pending timer's timeout |
704 | * @timer: the pending timer to be modified | |
705 | * @expires: new timeout in jiffies | |
1da177e4 | 706 | * |
74019224 IM |
707 | * mod_timer_pending() is the same for pending timers as mod_timer(), |
708 | * but will not re-activate and modify already deleted timers. | |
709 | * | |
710 | * It is useful for unserialized use of timers. | |
1da177e4 | 711 | */ |
74019224 | 712 | int mod_timer_pending(struct timer_list *timer, unsigned long expires) |
1da177e4 | 713 | { |
597d0275 | 714 | return __mod_timer(timer, expires, true, TIMER_NOT_PINNED); |
1da177e4 | 715 | } |
74019224 | 716 | EXPORT_SYMBOL(mod_timer_pending); |
1da177e4 | 717 | |
2aae4a10 | 718 | /** |
1da177e4 LT |
719 | * mod_timer - modify a timer's timeout |
720 | * @timer: the timer to be modified | |
2aae4a10 | 721 | * @expires: new timeout in jiffies |
1da177e4 | 722 | * |
72fd4a35 | 723 | * mod_timer() is a more efficient way to update the expire field of an |
1da177e4 LT |
724 | * active timer (if the timer is inactive it will be activated) |
725 | * | |
726 | * mod_timer(timer, expires) is equivalent to: | |
727 | * | |
728 | * del_timer(timer); timer->expires = expires; add_timer(timer); | |
729 | * | |
730 | * Note that if there are multiple unserialized concurrent users of the | |
731 | * same timer, then mod_timer() is the only safe way to modify the timeout, | |
732 | * since add_timer() cannot modify an already running timer. | |
733 | * | |
734 | * The function returns whether it has modified a pending timer or not. | |
735 | * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an | |
736 | * active timer returns 1.) | |
737 | */ | |
738 | int mod_timer(struct timer_list *timer, unsigned long expires) | |
739 | { | |
1da177e4 LT |
740 | /* |
741 | * This is a common optimization triggered by the | |
742 | * networking code - if the timer is re-modified | |
743 | * to be the same thing then just return: | |
744 | */ | |
4841158b | 745 | if (timer_pending(timer) && timer->expires == expires) |
1da177e4 LT |
746 | return 1; |
747 | ||
597d0275 | 748 | return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); |
1da177e4 | 749 | } |
1da177e4 LT |
750 | EXPORT_SYMBOL(mod_timer); |
751 | ||
597d0275 AB |
752 | /** |
753 | * mod_timer_pinned - modify a timer's timeout | |
754 | * @timer: the timer to be modified | |
755 | * @expires: new timeout in jiffies | |
756 | * | |
757 | * mod_timer_pinned() is a way to update the expire field of an | |
758 | * active timer (if the timer is inactive it will be activated) | |
759 | * and not allow the timer to be migrated to a different CPU. | |
760 | * | |
761 | * mod_timer_pinned(timer, expires) is equivalent to: | |
762 | * | |
763 | * del_timer(timer); timer->expires = expires; add_timer(timer); | |
764 | */ | |
765 | int mod_timer_pinned(struct timer_list *timer, unsigned long expires) | |
766 | { | |
767 | if (timer->expires == expires && timer_pending(timer)) | |
768 | return 1; | |
769 | ||
770 | return __mod_timer(timer, expires, false, TIMER_PINNED); | |
771 | } | |
772 | EXPORT_SYMBOL(mod_timer_pinned); | |
773 | ||
74019224 IM |
774 | /** |
775 | * add_timer - start a timer | |
776 | * @timer: the timer to be added | |
777 | * | |
778 | * The kernel will do a ->function(->data) callback from the | |
779 | * timer interrupt at the ->expires point in the future. The | |
780 | * current time is 'jiffies'. | |
781 | * | |
782 | * The timer's ->expires, ->function (and if the handler uses it, ->data) | |
783 | * fields must be set prior calling this function. | |
784 | * | |
785 | * Timers with an ->expires field in the past will be executed in the next | |
786 | * timer tick. | |
787 | */ | |
788 | void add_timer(struct timer_list *timer) | |
789 | { | |
790 | BUG_ON(timer_pending(timer)); | |
791 | mod_timer(timer, timer->expires); | |
792 | } | |
793 | EXPORT_SYMBOL(add_timer); | |
794 | ||
795 | /** | |
796 | * add_timer_on - start a timer on a particular CPU | |
797 | * @timer: the timer to be added | |
798 | * @cpu: the CPU to start it on | |
799 | * | |
800 | * This is not very scalable on SMP. Double adds are not possible. | |
801 | */ | |
802 | void add_timer_on(struct timer_list *timer, int cpu) | |
803 | { | |
804 | struct tvec_base *base = per_cpu(tvec_bases, cpu); | |
805 | unsigned long flags; | |
806 | ||
807 | timer_stats_timer_set_start_info(timer); | |
808 | BUG_ON(timer_pending(timer) || !timer->function); | |
809 | spin_lock_irqsave(&base->lock, flags); | |
810 | timer_set_base(timer, base); | |
2b022e3d | 811 | debug_activate(timer, timer->expires); |
97fd9ed4 MS |
812 | if (time_before(timer->expires, base->next_timer) && |
813 | !tbase_get_deferrable(timer->base)) | |
814 | base->next_timer = timer->expires; | |
74019224 IM |
815 | internal_add_timer(base, timer); |
816 | /* | |
817 | * Check whether the other CPU is idle and needs to be | |
818 | * triggered to reevaluate the timer wheel when nohz is | |
819 | * active. We are protected against the other CPU fiddling | |
820 | * with the timer by holding the timer base lock. This also | |
821 | * makes sure that a CPU on the way to idle can not evaluate | |
822 | * the timer wheel. | |
823 | */ | |
824 | wake_up_idle_cpu(cpu); | |
825 | spin_unlock_irqrestore(&base->lock, flags); | |
826 | } | |
a9862e05 | 827 | EXPORT_SYMBOL_GPL(add_timer_on); |
74019224 | 828 | |
2aae4a10 | 829 | /** |
1da177e4 LT |
830 | * del_timer - deactive a timer. |
831 | * @timer: the timer to be deactivated | |
832 | * | |
833 | * del_timer() deactivates a timer - this works on both active and inactive | |
834 | * timers. | |
835 | * | |
836 | * The function returns whether it has deactivated a pending timer or not. | |
837 | * (ie. del_timer() of an inactive timer returns 0, del_timer() of an | |
838 | * active timer returns 1.) | |
839 | */ | |
840 | int del_timer(struct timer_list *timer) | |
841 | { | |
a6fa8e5a | 842 | struct tvec_base *base; |
1da177e4 | 843 | unsigned long flags; |
55c888d6 | 844 | int ret = 0; |
1da177e4 | 845 | |
82f67cd9 | 846 | timer_stats_timer_clear_start_info(timer); |
55c888d6 ON |
847 | if (timer_pending(timer)) { |
848 | base = lock_timer_base(timer, &flags); | |
849 | if (timer_pending(timer)) { | |
850 | detach_timer(timer, 1); | |
97fd9ed4 MS |
851 | if (timer->expires == base->next_timer && |
852 | !tbase_get_deferrable(timer->base)) | |
853 | base->next_timer = base->timer_jiffies; | |
55c888d6 ON |
854 | ret = 1; |
855 | } | |
1da177e4 | 856 | spin_unlock_irqrestore(&base->lock, flags); |
1da177e4 | 857 | } |
1da177e4 | 858 | |
55c888d6 | 859 | return ret; |
1da177e4 | 860 | } |
1da177e4 LT |
861 | EXPORT_SYMBOL(del_timer); |
862 | ||
863 | #ifdef CONFIG_SMP | |
2aae4a10 REB |
864 | /** |
865 | * try_to_del_timer_sync - Try to deactivate a timer | |
866 | * @timer: timer do del | |
867 | * | |
fd450b73 ON |
868 | * This function tries to deactivate a timer. Upon successful (ret >= 0) |
869 | * exit the timer is not queued and the handler is not running on any CPU. | |
870 | * | |
871 | * It must not be called from interrupt contexts. | |
872 | */ | |
873 | int try_to_del_timer_sync(struct timer_list *timer) | |
874 | { | |
a6fa8e5a | 875 | struct tvec_base *base; |
fd450b73 ON |
876 | unsigned long flags; |
877 | int ret = -1; | |
878 | ||
879 | base = lock_timer_base(timer, &flags); | |
880 | ||
881 | if (base->running_timer == timer) | |
882 | goto out; | |
883 | ||
829b6c1e | 884 | timer_stats_timer_clear_start_info(timer); |
fd450b73 ON |
885 | ret = 0; |
886 | if (timer_pending(timer)) { | |
887 | detach_timer(timer, 1); | |
97fd9ed4 MS |
888 | if (timer->expires == base->next_timer && |
889 | !tbase_get_deferrable(timer->base)) | |
890 | base->next_timer = base->timer_jiffies; | |
fd450b73 ON |
891 | ret = 1; |
892 | } | |
893 | out: | |
894 | spin_unlock_irqrestore(&base->lock, flags); | |
895 | ||
896 | return ret; | |
897 | } | |
e19dff1f DH |
898 | EXPORT_SYMBOL(try_to_del_timer_sync); |
899 | ||
2aae4a10 | 900 | /** |
1da177e4 LT |
901 | * del_timer_sync - deactivate a timer and wait for the handler to finish. |
902 | * @timer: the timer to be deactivated | |
903 | * | |
904 | * This function only differs from del_timer() on SMP: besides deactivating | |
905 | * the timer it also makes sure the handler has finished executing on other | |
906 | * CPUs. | |
907 | * | |
72fd4a35 | 908 | * Synchronization rules: Callers must prevent restarting of the timer, |
1da177e4 LT |
909 | * otherwise this function is meaningless. It must not be called from |
910 | * interrupt contexts. The caller must not hold locks which would prevent | |
55c888d6 ON |
911 | * completion of the timer's handler. The timer's handler must not call |
912 | * add_timer_on(). Upon exit the timer is not queued and the handler is | |
913 | * not running on any CPU. | |
1da177e4 LT |
914 | * |
915 | * The function returns whether it has deactivated a pending timer or not. | |
1da177e4 LT |
916 | */ |
917 | int del_timer_sync(struct timer_list *timer) | |
918 | { | |
6f2b9b9a JB |
919 | #ifdef CONFIG_LOCKDEP |
920 | unsigned long flags; | |
921 | ||
922 | local_irq_save(flags); | |
923 | lock_map_acquire(&timer->lockdep_map); | |
924 | lock_map_release(&timer->lockdep_map); | |
925 | local_irq_restore(flags); | |
926 | #endif | |
927 | ||
fd450b73 ON |
928 | for (;;) { |
929 | int ret = try_to_del_timer_sync(timer); | |
930 | if (ret >= 0) | |
931 | return ret; | |
a0009652 | 932 | cpu_relax(); |
fd450b73 | 933 | } |
1da177e4 | 934 | } |
55c888d6 | 935 | EXPORT_SYMBOL(del_timer_sync); |
1da177e4 LT |
936 | #endif |
937 | ||
a6fa8e5a | 938 | static int cascade(struct tvec_base *base, struct tvec *tv, int index) |
1da177e4 LT |
939 | { |
940 | /* cascade all the timers from tv up one level */ | |
3439dd86 P |
941 | struct timer_list *timer, *tmp; |
942 | struct list_head tv_list; | |
943 | ||
944 | list_replace_init(tv->vec + index, &tv_list); | |
1da177e4 | 945 | |
1da177e4 | 946 | /* |
3439dd86 P |
947 | * We are removing _all_ timers from the list, so we |
948 | * don't have to detach them individually. | |
1da177e4 | 949 | */ |
3439dd86 | 950 | list_for_each_entry_safe(timer, tmp, &tv_list, entry) { |
6e453a67 | 951 | BUG_ON(tbase_get_base(timer->base) != base); |
3439dd86 | 952 | internal_add_timer(base, timer); |
1da177e4 | 953 | } |
1da177e4 LT |
954 | |
955 | return index; | |
956 | } | |
957 | ||
2aae4a10 REB |
958 | #define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) |
959 | ||
960 | /** | |
1da177e4 LT |
961 | * __run_timers - run all expired timers (if any) on this CPU. |
962 | * @base: the timer vector to be processed. | |
963 | * | |
964 | * This function cascades all vectors and executes all expired timer | |
965 | * vectors. | |
966 | */ | |
a6fa8e5a | 967 | static inline void __run_timers(struct tvec_base *base) |
1da177e4 LT |
968 | { |
969 | struct timer_list *timer; | |
970 | ||
3691c519 | 971 | spin_lock_irq(&base->lock); |
1da177e4 | 972 | while (time_after_eq(jiffies, base->timer_jiffies)) { |
626ab0e6 | 973 | struct list_head work_list; |
1da177e4 | 974 | struct list_head *head = &work_list; |
6819457d | 975 | int index = base->timer_jiffies & TVR_MASK; |
626ab0e6 | 976 | |
1da177e4 LT |
977 | /* |
978 | * Cascade timers: | |
979 | */ | |
980 | if (!index && | |
981 | (!cascade(base, &base->tv2, INDEX(0))) && | |
982 | (!cascade(base, &base->tv3, INDEX(1))) && | |
983 | !cascade(base, &base->tv4, INDEX(2))) | |
984 | cascade(base, &base->tv5, INDEX(3)); | |
626ab0e6 ON |
985 | ++base->timer_jiffies; |
986 | list_replace_init(base->tv1.vec + index, &work_list); | |
55c888d6 | 987 | while (!list_empty(head)) { |
1da177e4 LT |
988 | void (*fn)(unsigned long); |
989 | unsigned long data; | |
990 | ||
b5e61818 | 991 | timer = list_first_entry(head, struct timer_list,entry); |
6819457d TG |
992 | fn = timer->function; |
993 | data = timer->data; | |
1da177e4 | 994 | |
82f67cd9 IM |
995 | timer_stats_account_timer(timer); |
996 | ||
1da177e4 | 997 | set_running_timer(base, timer); |
55c888d6 | 998 | detach_timer(timer, 1); |
6f2b9b9a | 999 | |
3691c519 | 1000 | spin_unlock_irq(&base->lock); |
1da177e4 | 1001 | { |
be5b4fbd | 1002 | int preempt_count = preempt_count(); |
6f2b9b9a JB |
1003 | |
1004 | #ifdef CONFIG_LOCKDEP | |
1005 | /* | |
1006 | * It is permissible to free the timer from | |
1007 | * inside the function that is called from | |
1008 | * it, this we need to take into account for | |
1009 | * lockdep too. To avoid bogus "held lock | |
1010 | * freed" warnings as well as problems when | |
1011 | * looking into timer->lockdep_map, make a | |
1012 | * copy and use that here. | |
1013 | */ | |
1014 | struct lockdep_map lockdep_map = | |
1015 | timer->lockdep_map; | |
1016 | #endif | |
1017 | /* | |
1018 | * Couple the lock chain with the lock chain at | |
1019 | * del_timer_sync() by acquiring the lock_map | |
1020 | * around the fn() call here and in | |
1021 | * del_timer_sync(). | |
1022 | */ | |
1023 | lock_map_acquire(&lockdep_map); | |
1024 | ||
2b022e3d | 1025 | trace_timer_expire_entry(timer); |
1da177e4 | 1026 | fn(data); |
2b022e3d | 1027 | trace_timer_expire_exit(timer); |
6f2b9b9a JB |
1028 | |
1029 | lock_map_release(&lockdep_map); | |
1030 | ||
1da177e4 | 1031 | if (preempt_count != preempt_count()) { |
4c9dc641 | 1032 | printk(KERN_ERR "huh, entered %p " |
be5b4fbd JJ |
1033 | "with preempt_count %08x, exited" |
1034 | " with %08x?\n", | |
1035 | fn, preempt_count, | |
1036 | preempt_count()); | |
1da177e4 LT |
1037 | BUG(); |
1038 | } | |
1039 | } | |
3691c519 | 1040 | spin_lock_irq(&base->lock); |
1da177e4 LT |
1041 | } |
1042 | } | |
1043 | set_running_timer(base, NULL); | |
3691c519 | 1044 | spin_unlock_irq(&base->lock); |
1da177e4 LT |
1045 | } |
1046 | ||
ee9c5785 | 1047 | #ifdef CONFIG_NO_HZ |
1da177e4 LT |
1048 | /* |
1049 | * Find out when the next timer event is due to happen. This | |
90cba64a RD |
1050 | * is used on S/390 to stop all activity when a CPU is idle. |
1051 | * This function needs to be called with interrupts disabled. | |
1da177e4 | 1052 | */ |
a6fa8e5a | 1053 | static unsigned long __next_timer_interrupt(struct tvec_base *base) |
1da177e4 | 1054 | { |
1cfd6849 | 1055 | unsigned long timer_jiffies = base->timer_jiffies; |
eaad084b | 1056 | unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA; |
1cfd6849 | 1057 | int index, slot, array, found = 0; |
1da177e4 | 1058 | struct timer_list *nte; |
a6fa8e5a | 1059 | struct tvec *varray[4]; |
1da177e4 LT |
1060 | |
1061 | /* Look for timer events in tv1. */ | |
1cfd6849 | 1062 | index = slot = timer_jiffies & TVR_MASK; |
1da177e4 | 1063 | do { |
1cfd6849 | 1064 | list_for_each_entry(nte, base->tv1.vec + slot, entry) { |
6819457d TG |
1065 | if (tbase_get_deferrable(nte->base)) |
1066 | continue; | |
6e453a67 | 1067 | |
1cfd6849 | 1068 | found = 1; |
1da177e4 | 1069 | expires = nte->expires; |
1cfd6849 TG |
1070 | /* Look at the cascade bucket(s)? */ |
1071 | if (!index || slot < index) | |
1072 | goto cascade; | |
1073 | return expires; | |
1da177e4 | 1074 | } |
1cfd6849 TG |
1075 | slot = (slot + 1) & TVR_MASK; |
1076 | } while (slot != index); | |
1077 | ||
1078 | cascade: | |
1079 | /* Calculate the next cascade event */ | |
1080 | if (index) | |
1081 | timer_jiffies += TVR_SIZE - index; | |
1082 | timer_jiffies >>= TVR_BITS; | |
1da177e4 LT |
1083 | |
1084 | /* Check tv2-tv5. */ | |
1085 | varray[0] = &base->tv2; | |
1086 | varray[1] = &base->tv3; | |
1087 | varray[2] = &base->tv4; | |
1088 | varray[3] = &base->tv5; | |
1cfd6849 TG |
1089 | |
1090 | for (array = 0; array < 4; array++) { | |
a6fa8e5a | 1091 | struct tvec *varp = varray[array]; |
1cfd6849 TG |
1092 | |
1093 | index = slot = timer_jiffies & TVN_MASK; | |
1da177e4 | 1094 | do { |
1cfd6849 | 1095 | list_for_each_entry(nte, varp->vec + slot, entry) { |
a0419888 JH |
1096 | if (tbase_get_deferrable(nte->base)) |
1097 | continue; | |
1098 | ||
1cfd6849 | 1099 | found = 1; |
1da177e4 LT |
1100 | if (time_before(nte->expires, expires)) |
1101 | expires = nte->expires; | |
1cfd6849 TG |
1102 | } |
1103 | /* | |
1104 | * Do we still search for the first timer or are | |
1105 | * we looking up the cascade buckets ? | |
1106 | */ | |
1107 | if (found) { | |
1108 | /* Look at the cascade bucket(s)? */ | |
1109 | if (!index || slot < index) | |
1110 | break; | |
1111 | return expires; | |
1112 | } | |
1113 | slot = (slot + 1) & TVN_MASK; | |
1114 | } while (slot != index); | |
1115 | ||
1116 | if (index) | |
1117 | timer_jiffies += TVN_SIZE - index; | |
1118 | timer_jiffies >>= TVN_BITS; | |
1da177e4 | 1119 | } |
1cfd6849 TG |
1120 | return expires; |
1121 | } | |
69239749 | 1122 | |
1cfd6849 TG |
1123 | /* |
1124 | * Check, if the next hrtimer event is before the next timer wheel | |
1125 | * event: | |
1126 | */ | |
1127 | static unsigned long cmp_next_hrtimer_event(unsigned long now, | |
1128 | unsigned long expires) | |
1129 | { | |
1130 | ktime_t hr_delta = hrtimer_get_next_event(); | |
1131 | struct timespec tsdelta; | |
9501b6cf | 1132 | unsigned long delta; |
1cfd6849 TG |
1133 | |
1134 | if (hr_delta.tv64 == KTIME_MAX) | |
1135 | return expires; | |
0662b713 | 1136 | |
9501b6cf TG |
1137 | /* |
1138 | * Expired timer available, let it expire in the next tick | |
1139 | */ | |
1140 | if (hr_delta.tv64 <= 0) | |
1141 | return now + 1; | |
69239749 | 1142 | |
1cfd6849 | 1143 | tsdelta = ktime_to_timespec(hr_delta); |
9501b6cf | 1144 | delta = timespec_to_jiffies(&tsdelta); |
eaad084b TG |
1145 | |
1146 | /* | |
1147 | * Limit the delta to the max value, which is checked in | |
1148 | * tick_nohz_stop_sched_tick(): | |
1149 | */ | |
1150 | if (delta > NEXT_TIMER_MAX_DELTA) | |
1151 | delta = NEXT_TIMER_MAX_DELTA; | |
1152 | ||
9501b6cf TG |
1153 | /* |
1154 | * Take rounding errors in to account and make sure, that it | |
1155 | * expires in the next tick. Otherwise we go into an endless | |
1156 | * ping pong due to tick_nohz_stop_sched_tick() retriggering | |
1157 | * the timer softirq | |
1158 | */ | |
1159 | if (delta < 1) | |
1160 | delta = 1; | |
1161 | now += delta; | |
1cfd6849 TG |
1162 | if (time_before(now, expires)) |
1163 | return now; | |
1da177e4 LT |
1164 | return expires; |
1165 | } | |
1cfd6849 TG |
1166 | |
1167 | /** | |
8dce39c2 | 1168 | * get_next_timer_interrupt - return the jiffy of the next pending timer |
05fb6bf0 | 1169 | * @now: current time (in jiffies) |
1cfd6849 | 1170 | */ |
fd064b9b | 1171 | unsigned long get_next_timer_interrupt(unsigned long now) |
1cfd6849 | 1172 | { |
a6fa8e5a | 1173 | struct tvec_base *base = __get_cpu_var(tvec_bases); |
fd064b9b | 1174 | unsigned long expires; |
1cfd6849 TG |
1175 | |
1176 | spin_lock(&base->lock); | |
97fd9ed4 MS |
1177 | if (time_before_eq(base->next_timer, base->timer_jiffies)) |
1178 | base->next_timer = __next_timer_interrupt(base); | |
1179 | expires = base->next_timer; | |
1cfd6849 TG |
1180 | spin_unlock(&base->lock); |
1181 | ||
1182 | if (time_before_eq(expires, now)) | |
1183 | return now; | |
1184 | ||
1185 | return cmp_next_hrtimer_event(now, expires); | |
1186 | } | |
1da177e4 LT |
1187 | #endif |
1188 | ||
1da177e4 | 1189 | /* |
5b4db0c2 | 1190 | * Called from the timer interrupt handler to charge one tick to the current |
1da177e4 LT |
1191 | * process. user_tick is 1 if the tick is user time, 0 for system. |
1192 | */ | |
1193 | void update_process_times(int user_tick) | |
1194 | { | |
1195 | struct task_struct *p = current; | |
1196 | int cpu = smp_processor_id(); | |
1197 | ||
1198 | /* Note: this timer irq context must be accounted for as well. */ | |
fa13a5a1 | 1199 | account_process_tick(p, user_tick); |
1da177e4 | 1200 | run_local_timers(); |
a157229c | 1201 | rcu_check_callbacks(cpu, user_tick); |
b845b517 | 1202 | printk_tick(); |
fe432200 | 1203 | perf_event_do_pending(); |
1da177e4 | 1204 | scheduler_tick(); |
6819457d | 1205 | run_posix_cpu_timers(p); |
1da177e4 LT |
1206 | } |
1207 | ||
1da177e4 LT |
1208 | /* |
1209 | * This function runs timers and the timer-tq in bottom half context. | |
1210 | */ | |
1211 | static void run_timer_softirq(struct softirq_action *h) | |
1212 | { | |
a6fa8e5a | 1213 | struct tvec_base *base = __get_cpu_var(tvec_bases); |
1da177e4 | 1214 | |
d3d74453 | 1215 | hrtimer_run_pending(); |
82f67cd9 | 1216 | |
1da177e4 LT |
1217 | if (time_after_eq(jiffies, base->timer_jiffies)) |
1218 | __run_timers(base); | |
1219 | } | |
1220 | ||
1221 | /* | |
1222 | * Called by the local, per-CPU timer interrupt on SMP. | |
1223 | */ | |
1224 | void run_local_timers(void) | |
1225 | { | |
d3d74453 | 1226 | hrtimer_run_queues(); |
1da177e4 | 1227 | raise_softirq(TIMER_SOFTIRQ); |
6687a97d | 1228 | softlockup_tick(); |
1da177e4 LT |
1229 | } |
1230 | ||
1da177e4 LT |
1231 | /* |
1232 | * The 64-bit jiffies value is not atomic - you MUST NOT read it | |
1233 | * without sampling the sequence number in xtime_lock. | |
1234 | * jiffies is defined in the linker script... | |
1235 | */ | |
1236 | ||
3171a030 | 1237 | void do_timer(unsigned long ticks) |
1da177e4 | 1238 | { |
3171a030 | 1239 | jiffies_64 += ticks; |
dce48a84 TG |
1240 | update_wall_time(); |
1241 | calc_global_load(); | |
1da177e4 LT |
1242 | } |
1243 | ||
1244 | #ifdef __ARCH_WANT_SYS_ALARM | |
1245 | ||
1246 | /* | |
1247 | * For backwards compatibility? This can be done in libc so Alpha | |
1248 | * and all newer ports shouldn't need it. | |
1249 | */ | |
58fd3aa2 | 1250 | SYSCALL_DEFINE1(alarm, unsigned int, seconds) |
1da177e4 | 1251 | { |
c08b8a49 | 1252 | return alarm_setitimer(seconds); |
1da177e4 LT |
1253 | } |
1254 | ||
1255 | #endif | |
1256 | ||
1257 | #ifndef __alpha__ | |
1258 | ||
1259 | /* | |
1260 | * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this | |
1261 | * should be moved into arch/i386 instead? | |
1262 | */ | |
1263 | ||
1264 | /** | |
1265 | * sys_getpid - return the thread group id of the current process | |
1266 | * | |
1267 | * Note, despite the name, this returns the tgid not the pid. The tgid and | |
1268 | * the pid are identical unless CLONE_THREAD was specified on clone() in | |
1269 | * which case the tgid is the same in all threads of the same group. | |
1270 | * | |
1271 | * This is SMP safe as current->tgid does not change. | |
1272 | */ | |
58fd3aa2 | 1273 | SYSCALL_DEFINE0(getpid) |
1da177e4 | 1274 | { |
b488893a | 1275 | return task_tgid_vnr(current); |
1da177e4 LT |
1276 | } |
1277 | ||
1278 | /* | |
6997a6fa KK |
1279 | * Accessing ->real_parent is not SMP-safe, it could |
1280 | * change from under us. However, we can use a stale | |
1281 | * value of ->real_parent under rcu_read_lock(), see | |
1282 | * release_task()->call_rcu(delayed_put_task_struct). | |
1da177e4 | 1283 | */ |
dbf040d9 | 1284 | SYSCALL_DEFINE0(getppid) |
1da177e4 LT |
1285 | { |
1286 | int pid; | |
1da177e4 | 1287 | |
6997a6fa | 1288 | rcu_read_lock(); |
6c5f3e7b | 1289 | pid = task_tgid_vnr(current->real_parent); |
6997a6fa | 1290 | rcu_read_unlock(); |
1da177e4 | 1291 | |
1da177e4 LT |
1292 | return pid; |
1293 | } | |
1294 | ||
dbf040d9 | 1295 | SYSCALL_DEFINE0(getuid) |
1da177e4 LT |
1296 | { |
1297 | /* Only we change this so SMP safe */ | |
76aac0e9 | 1298 | return current_uid(); |
1da177e4 LT |
1299 | } |
1300 | ||
dbf040d9 | 1301 | SYSCALL_DEFINE0(geteuid) |
1da177e4 LT |
1302 | { |
1303 | /* Only we change this so SMP safe */ | |
76aac0e9 | 1304 | return current_euid(); |
1da177e4 LT |
1305 | } |
1306 | ||
dbf040d9 | 1307 | SYSCALL_DEFINE0(getgid) |
1da177e4 LT |
1308 | { |
1309 | /* Only we change this so SMP safe */ | |
76aac0e9 | 1310 | return current_gid(); |
1da177e4 LT |
1311 | } |
1312 | ||
dbf040d9 | 1313 | SYSCALL_DEFINE0(getegid) |
1da177e4 LT |
1314 | { |
1315 | /* Only we change this so SMP safe */ | |
76aac0e9 | 1316 | return current_egid(); |
1da177e4 LT |
1317 | } |
1318 | ||
1319 | #endif | |
1320 | ||
1321 | static void process_timeout(unsigned long __data) | |
1322 | { | |
36c8b586 | 1323 | wake_up_process((struct task_struct *)__data); |
1da177e4 LT |
1324 | } |
1325 | ||
1326 | /** | |
1327 | * schedule_timeout - sleep until timeout | |
1328 | * @timeout: timeout value in jiffies | |
1329 | * | |
1330 | * Make the current task sleep until @timeout jiffies have | |
1331 | * elapsed. The routine will return immediately unless | |
1332 | * the current task state has been set (see set_current_state()). | |
1333 | * | |
1334 | * You can set the task state as follows - | |
1335 | * | |
1336 | * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to | |
1337 | * pass before the routine returns. The routine will return 0 | |
1338 | * | |
1339 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
1340 | * delivered to the current task. In this case the remaining time | |
1341 | * in jiffies will be returned, or 0 if the timer expired in time | |
1342 | * | |
1343 | * The current task state is guaranteed to be TASK_RUNNING when this | |
1344 | * routine returns. | |
1345 | * | |
1346 | * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule | |
1347 | * the CPU away without a bound on the timeout. In this case the return | |
1348 | * value will be %MAX_SCHEDULE_TIMEOUT. | |
1349 | * | |
1350 | * In all cases the return value is guaranteed to be non-negative. | |
1351 | */ | |
7ad5b3a5 | 1352 | signed long __sched schedule_timeout(signed long timeout) |
1da177e4 LT |
1353 | { |
1354 | struct timer_list timer; | |
1355 | unsigned long expire; | |
1356 | ||
1357 | switch (timeout) | |
1358 | { | |
1359 | case MAX_SCHEDULE_TIMEOUT: | |
1360 | /* | |
1361 | * These two special cases are useful to be comfortable | |
1362 | * in the caller. Nothing more. We could take | |
1363 | * MAX_SCHEDULE_TIMEOUT from one of the negative value | |
1364 | * but I' d like to return a valid offset (>=0) to allow | |
1365 | * the caller to do everything it want with the retval. | |
1366 | */ | |
1367 | schedule(); | |
1368 | goto out; | |
1369 | default: | |
1370 | /* | |
1371 | * Another bit of PARANOID. Note that the retval will be | |
1372 | * 0 since no piece of kernel is supposed to do a check | |
1373 | * for a negative retval of schedule_timeout() (since it | |
1374 | * should never happens anyway). You just have the printk() | |
1375 | * that will tell you if something is gone wrong and where. | |
1376 | */ | |
5b149bcc | 1377 | if (timeout < 0) { |
1da177e4 | 1378 | printk(KERN_ERR "schedule_timeout: wrong timeout " |
5b149bcc AM |
1379 | "value %lx\n", timeout); |
1380 | dump_stack(); | |
1da177e4 LT |
1381 | current->state = TASK_RUNNING; |
1382 | goto out; | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | expire = timeout + jiffies; | |
1387 | ||
c6f3a97f | 1388 | setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); |
597d0275 | 1389 | __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); |
1da177e4 LT |
1390 | schedule(); |
1391 | del_singleshot_timer_sync(&timer); | |
1392 | ||
c6f3a97f TG |
1393 | /* Remove the timer from the object tracker */ |
1394 | destroy_timer_on_stack(&timer); | |
1395 | ||
1da177e4 LT |
1396 | timeout = expire - jiffies; |
1397 | ||
1398 | out: | |
1399 | return timeout < 0 ? 0 : timeout; | |
1400 | } | |
1da177e4 LT |
1401 | EXPORT_SYMBOL(schedule_timeout); |
1402 | ||
8a1c1757 AM |
1403 | /* |
1404 | * We can use __set_current_state() here because schedule_timeout() calls | |
1405 | * schedule() unconditionally. | |
1406 | */ | |
64ed93a2 NA |
1407 | signed long __sched schedule_timeout_interruptible(signed long timeout) |
1408 | { | |
a5a0d52c AM |
1409 | __set_current_state(TASK_INTERRUPTIBLE); |
1410 | return schedule_timeout(timeout); | |
64ed93a2 NA |
1411 | } |
1412 | EXPORT_SYMBOL(schedule_timeout_interruptible); | |
1413 | ||
294d5cc2 MW |
1414 | signed long __sched schedule_timeout_killable(signed long timeout) |
1415 | { | |
1416 | __set_current_state(TASK_KILLABLE); | |
1417 | return schedule_timeout(timeout); | |
1418 | } | |
1419 | EXPORT_SYMBOL(schedule_timeout_killable); | |
1420 | ||
64ed93a2 NA |
1421 | signed long __sched schedule_timeout_uninterruptible(signed long timeout) |
1422 | { | |
a5a0d52c AM |
1423 | __set_current_state(TASK_UNINTERRUPTIBLE); |
1424 | return schedule_timeout(timeout); | |
64ed93a2 NA |
1425 | } |
1426 | EXPORT_SYMBOL(schedule_timeout_uninterruptible); | |
1427 | ||
1da177e4 | 1428 | /* Thread ID - the internal kernel "pid" */ |
58fd3aa2 | 1429 | SYSCALL_DEFINE0(gettid) |
1da177e4 | 1430 | { |
b488893a | 1431 | return task_pid_vnr(current); |
1da177e4 LT |
1432 | } |
1433 | ||
2aae4a10 | 1434 | /** |
d4d23add | 1435 | * do_sysinfo - fill in sysinfo struct |
2aae4a10 | 1436 | * @info: pointer to buffer to fill |
6819457d | 1437 | */ |
d4d23add | 1438 | int do_sysinfo(struct sysinfo *info) |
1da177e4 | 1439 | { |
1da177e4 LT |
1440 | unsigned long mem_total, sav_total; |
1441 | unsigned int mem_unit, bitcount; | |
2d02494f | 1442 | struct timespec tp; |
1da177e4 | 1443 | |
d4d23add | 1444 | memset(info, 0, sizeof(struct sysinfo)); |
1da177e4 | 1445 | |
2d02494f TG |
1446 | ktime_get_ts(&tp); |
1447 | monotonic_to_bootbased(&tp); | |
1448 | info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); | |
1da177e4 | 1449 | |
2d02494f | 1450 | get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); |
1da177e4 | 1451 | |
2d02494f | 1452 | info->procs = nr_threads; |
1da177e4 | 1453 | |
d4d23add KM |
1454 | si_meminfo(info); |
1455 | si_swapinfo(info); | |
1da177e4 LT |
1456 | |
1457 | /* | |
1458 | * If the sum of all the available memory (i.e. ram + swap) | |
1459 | * is less than can be stored in a 32 bit unsigned long then | |
1460 | * we can be binary compatible with 2.2.x kernels. If not, | |
1461 | * well, in that case 2.2.x was broken anyways... | |
1462 | * | |
1463 | * -Erik Andersen <andersee@debian.org> | |
1464 | */ | |
1465 | ||
d4d23add KM |
1466 | mem_total = info->totalram + info->totalswap; |
1467 | if (mem_total < info->totalram || mem_total < info->totalswap) | |
1da177e4 LT |
1468 | goto out; |
1469 | bitcount = 0; | |
d4d23add | 1470 | mem_unit = info->mem_unit; |
1da177e4 LT |
1471 | while (mem_unit > 1) { |
1472 | bitcount++; | |
1473 | mem_unit >>= 1; | |
1474 | sav_total = mem_total; | |
1475 | mem_total <<= 1; | |
1476 | if (mem_total < sav_total) | |
1477 | goto out; | |
1478 | } | |
1479 | ||
1480 | /* | |
1481 | * If mem_total did not overflow, multiply all memory values by | |
d4d23add | 1482 | * info->mem_unit and set it to 1. This leaves things compatible |
1da177e4 LT |
1483 | * with 2.2.x, and also retains compatibility with earlier 2.4.x |
1484 | * kernels... | |
1485 | */ | |
1486 | ||
d4d23add KM |
1487 | info->mem_unit = 1; |
1488 | info->totalram <<= bitcount; | |
1489 | info->freeram <<= bitcount; | |
1490 | info->sharedram <<= bitcount; | |
1491 | info->bufferram <<= bitcount; | |
1492 | info->totalswap <<= bitcount; | |
1493 | info->freeswap <<= bitcount; | |
1494 | info->totalhigh <<= bitcount; | |
1495 | info->freehigh <<= bitcount; | |
1496 | ||
1497 | out: | |
1498 | return 0; | |
1499 | } | |
1500 | ||
1e7bfb21 | 1501 | SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) |
d4d23add KM |
1502 | { |
1503 | struct sysinfo val; | |
1504 | ||
1505 | do_sysinfo(&val); | |
1da177e4 | 1506 | |
1da177e4 LT |
1507 | if (copy_to_user(info, &val, sizeof(struct sysinfo))) |
1508 | return -EFAULT; | |
1509 | ||
1510 | return 0; | |
1511 | } | |
1512 | ||
b4be6258 | 1513 | static int __cpuinit init_timers_cpu(int cpu) |
1da177e4 LT |
1514 | { |
1515 | int j; | |
a6fa8e5a | 1516 | struct tvec_base *base; |
b4be6258 | 1517 | static char __cpuinitdata tvec_base_done[NR_CPUS]; |
55c888d6 | 1518 | |
ba6edfcd | 1519 | if (!tvec_base_done[cpu]) { |
a4a6198b JB |
1520 | static char boot_done; |
1521 | ||
a4a6198b | 1522 | if (boot_done) { |
ba6edfcd AM |
1523 | /* |
1524 | * The APs use this path later in boot | |
1525 | */ | |
94f6030c CL |
1526 | base = kmalloc_node(sizeof(*base), |
1527 | GFP_KERNEL | __GFP_ZERO, | |
a4a6198b JB |
1528 | cpu_to_node(cpu)); |
1529 | if (!base) | |
1530 | return -ENOMEM; | |
6e453a67 VP |
1531 | |
1532 | /* Make sure that tvec_base is 2 byte aligned */ | |
1533 | if (tbase_get_deferrable(base)) { | |
1534 | WARN_ON(1); | |
1535 | kfree(base); | |
1536 | return -ENOMEM; | |
1537 | } | |
ba6edfcd | 1538 | per_cpu(tvec_bases, cpu) = base; |
a4a6198b | 1539 | } else { |
ba6edfcd AM |
1540 | /* |
1541 | * This is for the boot CPU - we use compile-time | |
1542 | * static initialisation because per-cpu memory isn't | |
1543 | * ready yet and because the memory allocators are not | |
1544 | * initialised either. | |
1545 | */ | |
a4a6198b | 1546 | boot_done = 1; |
ba6edfcd | 1547 | base = &boot_tvec_bases; |
a4a6198b | 1548 | } |
ba6edfcd AM |
1549 | tvec_base_done[cpu] = 1; |
1550 | } else { | |
1551 | base = per_cpu(tvec_bases, cpu); | |
a4a6198b | 1552 | } |
ba6edfcd | 1553 | |
3691c519 | 1554 | spin_lock_init(&base->lock); |
d730e882 | 1555 | |
1da177e4 LT |
1556 | for (j = 0; j < TVN_SIZE; j++) { |
1557 | INIT_LIST_HEAD(base->tv5.vec + j); | |
1558 | INIT_LIST_HEAD(base->tv4.vec + j); | |
1559 | INIT_LIST_HEAD(base->tv3.vec + j); | |
1560 | INIT_LIST_HEAD(base->tv2.vec + j); | |
1561 | } | |
1562 | for (j = 0; j < TVR_SIZE; j++) | |
1563 | INIT_LIST_HEAD(base->tv1.vec + j); | |
1564 | ||
1565 | base->timer_jiffies = jiffies; | |
97fd9ed4 | 1566 | base->next_timer = base->timer_jiffies; |
a4a6198b | 1567 | return 0; |
1da177e4 LT |
1568 | } |
1569 | ||
1570 | #ifdef CONFIG_HOTPLUG_CPU | |
a6fa8e5a | 1571 | static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) |
1da177e4 LT |
1572 | { |
1573 | struct timer_list *timer; | |
1574 | ||
1575 | while (!list_empty(head)) { | |
b5e61818 | 1576 | timer = list_first_entry(head, struct timer_list, entry); |
55c888d6 | 1577 | detach_timer(timer, 0); |
6e453a67 | 1578 | timer_set_base(timer, new_base); |
97fd9ed4 MS |
1579 | if (time_before(timer->expires, new_base->next_timer) && |
1580 | !tbase_get_deferrable(timer->base)) | |
1581 | new_base->next_timer = timer->expires; | |
1da177e4 | 1582 | internal_add_timer(new_base, timer); |
1da177e4 | 1583 | } |
1da177e4 LT |
1584 | } |
1585 | ||
48ccf3da | 1586 | static void __cpuinit migrate_timers(int cpu) |
1da177e4 | 1587 | { |
a6fa8e5a PM |
1588 | struct tvec_base *old_base; |
1589 | struct tvec_base *new_base; | |
1da177e4 LT |
1590 | int i; |
1591 | ||
1592 | BUG_ON(cpu_online(cpu)); | |
a4a6198b JB |
1593 | old_base = per_cpu(tvec_bases, cpu); |
1594 | new_base = get_cpu_var(tvec_bases); | |
d82f0b0f ON |
1595 | /* |
1596 | * The caller is globally serialized and nobody else | |
1597 | * takes two locks at once, deadlock is not possible. | |
1598 | */ | |
1599 | spin_lock_irq(&new_base->lock); | |
0d180406 | 1600 | spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); |
3691c519 ON |
1601 | |
1602 | BUG_ON(old_base->running_timer); | |
1da177e4 | 1603 | |
1da177e4 | 1604 | for (i = 0; i < TVR_SIZE; i++) |
55c888d6 ON |
1605 | migrate_timer_list(new_base, old_base->tv1.vec + i); |
1606 | for (i = 0; i < TVN_SIZE; i++) { | |
1607 | migrate_timer_list(new_base, old_base->tv2.vec + i); | |
1608 | migrate_timer_list(new_base, old_base->tv3.vec + i); | |
1609 | migrate_timer_list(new_base, old_base->tv4.vec + i); | |
1610 | migrate_timer_list(new_base, old_base->tv5.vec + i); | |
1611 | } | |
1612 | ||
0d180406 | 1613 | spin_unlock(&old_base->lock); |
d82f0b0f | 1614 | spin_unlock_irq(&new_base->lock); |
1da177e4 | 1615 | put_cpu_var(tvec_bases); |
1da177e4 LT |
1616 | } |
1617 | #endif /* CONFIG_HOTPLUG_CPU */ | |
1618 | ||
8c78f307 | 1619 | static int __cpuinit timer_cpu_notify(struct notifier_block *self, |
1da177e4 LT |
1620 | unsigned long action, void *hcpu) |
1621 | { | |
1622 | long cpu = (long)hcpu; | |
1623 | switch(action) { | |
1624 | case CPU_UP_PREPARE: | |
8bb78442 | 1625 | case CPU_UP_PREPARE_FROZEN: |
a4a6198b JB |
1626 | if (init_timers_cpu(cpu) < 0) |
1627 | return NOTIFY_BAD; | |
1da177e4 LT |
1628 | break; |
1629 | #ifdef CONFIG_HOTPLUG_CPU | |
1630 | case CPU_DEAD: | |
8bb78442 | 1631 | case CPU_DEAD_FROZEN: |
1da177e4 LT |
1632 | migrate_timers(cpu); |
1633 | break; | |
1634 | #endif | |
1635 | default: | |
1636 | break; | |
1637 | } | |
1638 | return NOTIFY_OK; | |
1639 | } | |
1640 | ||
8c78f307 | 1641 | static struct notifier_block __cpuinitdata timers_nb = { |
1da177e4 LT |
1642 | .notifier_call = timer_cpu_notify, |
1643 | }; | |
1644 | ||
1645 | ||
1646 | void __init init_timers(void) | |
1647 | { | |
07dccf33 | 1648 | int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, |
1da177e4 | 1649 | (void *)(long)smp_processor_id()); |
07dccf33 | 1650 | |
82f67cd9 IM |
1651 | init_timer_stats(); |
1652 | ||
07dccf33 | 1653 | BUG_ON(err == NOTIFY_BAD); |
1da177e4 | 1654 | register_cpu_notifier(&timers_nb); |
962cf36c | 1655 | open_softirq(TIMER_SOFTIRQ, run_timer_softirq); |
1da177e4 LT |
1656 | } |
1657 | ||
1da177e4 LT |
1658 | /** |
1659 | * msleep - sleep safely even with waitqueue interruptions | |
1660 | * @msecs: Time in milliseconds to sleep for | |
1661 | */ | |
1662 | void msleep(unsigned int msecs) | |
1663 | { | |
1664 | unsigned long timeout = msecs_to_jiffies(msecs) + 1; | |
1665 | ||
75bcc8c5 NA |
1666 | while (timeout) |
1667 | timeout = schedule_timeout_uninterruptible(timeout); | |
1da177e4 LT |
1668 | } |
1669 | ||
1670 | EXPORT_SYMBOL(msleep); | |
1671 | ||
1672 | /** | |
96ec3efd | 1673 | * msleep_interruptible - sleep waiting for signals |
1da177e4 LT |
1674 | * @msecs: Time in milliseconds to sleep for |
1675 | */ | |
1676 | unsigned long msleep_interruptible(unsigned int msecs) | |
1677 | { | |
1678 | unsigned long timeout = msecs_to_jiffies(msecs) + 1; | |
1679 | ||
75bcc8c5 NA |
1680 | while (timeout && !signal_pending(current)) |
1681 | timeout = schedule_timeout_interruptible(timeout); | |
1da177e4 LT |
1682 | return jiffies_to_msecs(timeout); |
1683 | } | |
1684 | ||
1685 | EXPORT_SYMBOL(msleep_interruptible); |