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Commit | Line | Data |
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c0a31329 TG |
1 | /* |
2 | * include/linux/hrtimer.h | |
3 | * | |
4 | * hrtimers - High-resolution kernel timers | |
5 | * | |
6 | * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> | |
7 | * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar | |
8 | * | |
9 | * data type definitions, declarations, prototypes | |
10 | * | |
11 | * Started by: Thomas Gleixner and Ingo Molnar | |
12 | * | |
13 | * For licencing details see kernel-base/COPYING | |
14 | */ | |
15 | #ifndef _LINUX_HRTIMER_H | |
16 | #define _LINUX_HRTIMER_H | |
17 | ||
18 | #include <linux/rbtree.h> | |
19 | #include <linux/ktime.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/list.h> | |
22 | #include <linux/wait.h> | |
40b86062 | 23 | #include <linux/percpu.h> |
507e1231 | 24 | #include <linux/timer.h> |
998adc3d | 25 | #include <linux/timerqueue.h> |
c0a31329 | 26 | |
3c8aa39d TG |
27 | struct hrtimer_clock_base; |
28 | struct hrtimer_cpu_base; | |
29 | ||
c0a31329 TG |
30 | /* |
31 | * Mode arguments of xxx_hrtimer functions: | |
32 | */ | |
33 | enum hrtimer_mode { | |
597d0275 AB |
34 | HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */ |
35 | HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */ | |
36 | HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */ | |
37 | HRTIMER_MODE_ABS_PINNED = 0x02, | |
38 | HRTIMER_MODE_REL_PINNED = 0x03, | |
c0a31329 TG |
39 | }; |
40 | ||
c9cb2e3d TG |
41 | /* |
42 | * Return values for the callback function | |
43 | */ | |
c0a31329 | 44 | enum hrtimer_restart { |
c9cb2e3d TG |
45 | HRTIMER_NORESTART, /* Timer is not restarted */ |
46 | HRTIMER_RESTART, /* Timer must be restarted */ | |
c0a31329 TG |
47 | }; |
48 | ||
54cdfdb4 TG |
49 | /* |
50 | * Values to track state of the timer | |
303e967f TG |
51 | * |
52 | * Possible states: | |
53 | * | |
54 | * 0x00 inactive | |
55 | * 0x01 enqueued into rbtree | |
56 | * 0x02 callback function running | |
53370d2e | 57 | * 0x04 timer is migrated to another cpu |
54cdfdb4 | 58 | * |
b00c1a99 | 59 | * Special cases: |
303e967f TG |
60 | * 0x03 callback function running and enqueued |
61 | * (was requeued on another CPU) | |
53370d2e TG |
62 | * 0x05 timer was migrated on CPU hotunplug |
63 | * | |
303e967f TG |
64 | * The "callback function running and enqueued" status is only possible on |
65 | * SMP. It happens for example when a posix timer expired and the callback | |
66 | * queued a signal. Between dropping the lock which protects the posix timer | |
67 | * and reacquiring the base lock of the hrtimer, another CPU can deliver the | |
68 | * signal and rearm the timer. We have to preserve the callback running state, | |
69 | * as otherwise the timer could be removed before the softirq code finishes the | |
70 | * the handling of the timer. | |
71 | * | |
53370d2e TG |
72 | * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state |
73 | * to preserve the HRTIMER_STATE_CALLBACK in the above scenario. This | |
74 | * also affects HRTIMER_STATE_MIGRATE where the preservation is not | |
75 | * necessary. HRTIMER_STATE_MIGRATE is cleared after the timer is | |
76 | * enqueued on the new cpu. | |
303e967f TG |
77 | * |
78 | * All state transitions are protected by cpu_base->lock. | |
79 | */ | |
80 | #define HRTIMER_STATE_INACTIVE 0x00 | |
81 | #define HRTIMER_STATE_ENQUEUED 0x01 | |
82 | #define HRTIMER_STATE_CALLBACK 0x02 | |
ca109491 | 83 | #define HRTIMER_STATE_MIGRATE 0x04 |
303e967f | 84 | |
c0a31329 TG |
85 | /** |
86 | * struct hrtimer - the basic hrtimer structure | |
998adc3d JS |
87 | * @node: timerqueue node, which also manages node.expires, |
88 | * the absolute expiry time in the hrtimers internal | |
c0a31329 | 89 | * representation. The time is related to the clock on |
592aa999 TG |
90 | * which the timer is based. Is setup by adding |
91 | * slack to the _softexpires value. For non range timers | |
92 | * identical to _softexpires. | |
93 | * @_softexpires: the absolute earliest expiry time of the hrtimer. | |
94 | * The time which was given as expiry time when the timer | |
95 | * was armed. | |
c0a31329 | 96 | * @function: timer expiry callback function |
c0a31329 | 97 | * @base: pointer to the timer base (per cpu and per clock) |
303e967f | 98 | * @state: state information (See bit values above) |
e2e680fb VK |
99 | * @start_pid: timer statistics field to store the pid of the task which |
100 | * started the timer | |
54cdfdb4 TG |
101 | * @start_site: timer statistics field to store the site where the timer |
102 | * was started | |
103 | * @start_comm: timer statistics field to store the name of the process which | |
104 | * started the timer | |
c0a31329 | 105 | * |
54cdfdb4 | 106 | * The hrtimer structure must be initialized by hrtimer_init() |
c0a31329 TG |
107 | */ |
108 | struct hrtimer { | |
998adc3d | 109 | struct timerqueue_node node; |
654c8e0b | 110 | ktime_t _softexpires; |
3c8aa39d TG |
111 | enum hrtimer_restart (*function)(struct hrtimer *); |
112 | struct hrtimer_clock_base *base; | |
303e967f | 113 | unsigned long state; |
82f67cd9 | 114 | #ifdef CONFIG_TIMER_STATS |
1b024690 | 115 | int start_pid; |
82f67cd9 IM |
116 | void *start_site; |
117 | char start_comm[16]; | |
82f67cd9 | 118 | #endif |
c0a31329 TG |
119 | }; |
120 | ||
00362e33 TG |
121 | /** |
122 | * struct hrtimer_sleeper - simple sleeper structure | |
00362e33 TG |
123 | * @timer: embedded timer structure |
124 | * @task: task to wake up | |
125 | * | |
126 | * task is set to NULL, when the timer expires. | |
127 | */ | |
128 | struct hrtimer_sleeper { | |
129 | struct hrtimer timer; | |
130 | struct task_struct *task; | |
131 | }; | |
132 | ||
c0a31329 | 133 | /** |
d1d67174 | 134 | * struct hrtimer_clock_base - the timer base for a specific clock |
05fb6bf0 | 135 | * @cpu_base: per cpu clock base |
3c8aa39d TG |
136 | * @index: clock type index for per_cpu support when moving a |
137 | * timer to a base on another cpu. | |
4d258b25 | 138 | * @clockid: clock id for per_cpu support |
92127c7a | 139 | * @active: red black tree root node for the active timers |
92127c7a | 140 | * @get_time: function to retrieve the current time of the clock |
92127c7a | 141 | * @softirq_time: the time when running the hrtimer queue in the softirq |
54cdfdb4 | 142 | * @offset: offset of this clock to the monotonic base |
c0a31329 | 143 | */ |
3c8aa39d TG |
144 | struct hrtimer_clock_base { |
145 | struct hrtimer_cpu_base *cpu_base; | |
ab8177bc TG |
146 | int index; |
147 | clockid_t clockid; | |
998adc3d | 148 | struct timerqueue_head active; |
c0a31329 | 149 | ktime_t (*get_time)(void); |
92127c7a | 150 | ktime_t softirq_time; |
54cdfdb4 | 151 | ktime_t offset; |
3c8aa39d TG |
152 | }; |
153 | ||
e06383db | 154 | enum hrtimer_base_type { |
e06383db | 155 | HRTIMER_BASE_MONOTONIC, |
68fa61c0 | 156 | HRTIMER_BASE_REALTIME, |
70a08cca | 157 | HRTIMER_BASE_BOOTTIME, |
90adda98 | 158 | HRTIMER_BASE_TAI, |
e06383db JS |
159 | HRTIMER_MAX_CLOCK_BASES, |
160 | }; | |
3c8aa39d TG |
161 | |
162 | /* | |
163 | * struct hrtimer_cpu_base - the per cpu clock bases | |
164 | * @lock: lock protecting the base and associated clock bases | |
165 | * and timers | |
cddd0248 | 166 | * @cpu: cpu number |
ab8177bc | 167 | * @active_bases: Bitfield to mark bases with active timers |
f55a6faa | 168 | * @clock_was_set: Indicates that clock was set from irq context. |
54cdfdb4 TG |
169 | * @expires_next: absolute time of the next event which was scheduled |
170 | * via clock_set_next_event() | |
9bc74919 | 171 | * @in_hrtirq: hrtimer_interrupt() is currently executing |
54cdfdb4 | 172 | * @hres_active: State of high resolution mode |
41d2e494 TG |
173 | * @hang_detected: The last hrtimer interrupt detected a hang |
174 | * @nr_events: Total number of hrtimer interrupt events | |
175 | * @nr_retries: Total number of hrtimer interrupt retries | |
176 | * @nr_hangs: Total number of hrtimer interrupt hangs | |
177 | * @max_hang_time: Maximum time spent in hrtimer_interrupt | |
ab8177bc | 178 | * @clock_base: array of clock bases for this cpu |
3c8aa39d TG |
179 | */ |
180 | struct hrtimer_cpu_base { | |
ecb49d1a | 181 | raw_spinlock_t lock; |
cddd0248 | 182 | unsigned int cpu; |
f55a6faa JS |
183 | unsigned int active_bases; |
184 | unsigned int clock_was_set; | |
54cdfdb4 TG |
185 | #ifdef CONFIG_HIGH_RES_TIMERS |
186 | ktime_t expires_next; | |
9bc74919 | 187 | int in_hrtirq; |
54cdfdb4 | 188 | int hres_active; |
41d2e494 | 189 | int hang_detected; |
a6ffebce TG |
190 | unsigned int nr_events; |
191 | unsigned int nr_retries; | |
192 | unsigned int nr_hangs; | |
193 | unsigned int max_hang_time; | |
54cdfdb4 | 194 | #endif |
f24444b0 | 195 | struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; |
c0a31329 TG |
196 | }; |
197 | ||
63ca243b AV |
198 | static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) |
199 | { | |
998adc3d | 200 | timer->node.expires = time; |
654c8e0b | 201 | timer->_softexpires = time; |
63ca243b | 202 | } |
654c8e0b AV |
203 | |
204 | static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) | |
205 | { | |
206 | timer->_softexpires = time; | |
998adc3d | 207 | timer->node.expires = ktime_add_safe(time, delta); |
654c8e0b AV |
208 | } |
209 | ||
210 | static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) | |
211 | { | |
212 | timer->_softexpires = time; | |
998adc3d | 213 | timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); |
654c8e0b AV |
214 | } |
215 | ||
63ca243b AV |
216 | static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) |
217 | { | |
998adc3d | 218 | timer->node.expires.tv64 = tv64; |
654c8e0b | 219 | timer->_softexpires.tv64 = tv64; |
63ca243b AV |
220 | } |
221 | ||
222 | static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) | |
223 | { | |
998adc3d | 224 | timer->node.expires = ktime_add_safe(timer->node.expires, time); |
654c8e0b | 225 | timer->_softexpires = ktime_add_safe(timer->_softexpires, time); |
63ca243b AV |
226 | } |
227 | ||
7597bc94 | 228 | static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) |
63ca243b | 229 | { |
998adc3d | 230 | timer->node.expires = ktime_add_ns(timer->node.expires, ns); |
654c8e0b | 231 | timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); |
63ca243b AV |
232 | } |
233 | ||
234 | static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) | |
235 | { | |
998adc3d | 236 | return timer->node.expires; |
63ca243b AV |
237 | } |
238 | ||
654c8e0b AV |
239 | static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) |
240 | { | |
241 | return timer->_softexpires; | |
242 | } | |
243 | ||
63ca243b AV |
244 | static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) |
245 | { | |
998adc3d | 246 | return timer->node.expires.tv64; |
63ca243b | 247 | } |
654c8e0b AV |
248 | static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) |
249 | { | |
250 | return timer->_softexpires.tv64; | |
251 | } | |
63ca243b AV |
252 | |
253 | static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) | |
254 | { | |
998adc3d | 255 | return ktime_to_ns(timer->node.expires); |
63ca243b AV |
256 | } |
257 | ||
258 | static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) | |
259 | { | |
998adc3d | 260 | return ktime_sub(timer->node.expires, timer->base->get_time()); |
63ca243b AV |
261 | } |
262 | ||
54cdfdb4 TG |
263 | #ifdef CONFIG_HIGH_RES_TIMERS |
264 | struct clock_event_device; | |
265 | ||
54cdfdb4 TG |
266 | extern void hrtimer_interrupt(struct clock_event_device *dev); |
267 | ||
268 | /* | |
269 | * In high resolution mode the time reference must be read accurate | |
270 | */ | |
271 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
272 | { | |
273 | return timer->base->get_time(); | |
274 | } | |
275 | ||
8f4d37ec PZ |
276 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
277 | { | |
278 | return timer->base->cpu_base->hres_active; | |
279 | } | |
280 | ||
2075eb8d AV |
281 | extern void hrtimer_peek_ahead_timers(void); |
282 | ||
54cdfdb4 TG |
283 | /* |
284 | * The resolution of the clocks. The resolution value is returned in | |
285 | * the clock_getres() system call to give application programmers an | |
286 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
287 | * this resolution values. | |
288 | */ | |
151db1fc TB |
289 | # define HIGH_RES_NSEC 1 |
290 | # define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC } | |
291 | # define MONOTONIC_RES_NSEC HIGH_RES_NSEC | |
54cdfdb4 TG |
292 | # define KTIME_MONOTONIC_RES KTIME_HIGH_RES |
293 | ||
f55a6faa JS |
294 | extern void clock_was_set_delayed(void); |
295 | ||
398ca17f TG |
296 | extern unsigned int hrtimer_resolution; |
297 | ||
54cdfdb4 TG |
298 | #else |
299 | ||
151db1fc | 300 | # define MONOTONIC_RES_NSEC LOW_RES_NSEC |
54cdfdb4 TG |
301 | # define KTIME_MONOTONIC_RES KTIME_LOW_RES |
302 | ||
398ca17f TG |
303 | #define hrtimer_resolution LOW_RES_NSEC |
304 | ||
2075eb8d | 305 | static inline void hrtimer_peek_ahead_timers(void) { } |
54cdfdb4 TG |
306 | |
307 | /* | |
308 | * In non high resolution mode the time reference is taken from | |
309 | * the base softirq time variable. | |
310 | */ | |
311 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
312 | { | |
313 | return timer->base->softirq_time; | |
314 | } | |
315 | ||
8f4d37ec PZ |
316 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
317 | { | |
318 | return 0; | |
319 | } | |
f55a6faa JS |
320 | |
321 | static inline void clock_was_set_delayed(void) { } | |
322 | ||
54cdfdb4 TG |
323 | #endif |
324 | ||
b12a03ce | 325 | extern void clock_was_set(void); |
9ec26907 TG |
326 | #ifdef CONFIG_TIMERFD |
327 | extern void timerfd_clock_was_set(void); | |
328 | #else | |
329 | static inline void timerfd_clock_was_set(void) { } | |
330 | #endif | |
b12a03ce TG |
331 | extern void hrtimers_resume(void); |
332 | ||
2e94d1f7 | 333 | DECLARE_PER_CPU(struct tick_device, tick_cpu_device); |
2e94d1f7 AV |
334 | |
335 | ||
c0a31329 TG |
336 | /* Exported timer functions: */ |
337 | ||
338 | /* Initialize timers: */ | |
7978672c GA |
339 | extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, |
340 | enum hrtimer_mode mode); | |
c0a31329 | 341 | |
237fc6e7 TG |
342 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
343 | extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, | |
344 | enum hrtimer_mode mode); | |
345 | ||
346 | extern void destroy_hrtimer_on_stack(struct hrtimer *timer); | |
347 | #else | |
348 | static inline void hrtimer_init_on_stack(struct hrtimer *timer, | |
349 | clockid_t which_clock, | |
350 | enum hrtimer_mode mode) | |
351 | { | |
352 | hrtimer_init(timer, which_clock, mode); | |
353 | } | |
354 | static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } | |
355 | #endif | |
356 | ||
c0a31329 TG |
357 | /* Basic timer operations: */ |
358 | extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, | |
359 | const enum hrtimer_mode mode); | |
da8f2e17 AV |
360 | extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
361 | unsigned long range_ns, const enum hrtimer_mode mode); | |
7f1e2ca9 PZ |
362 | extern int |
363 | __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
364 | unsigned long delta_ns, | |
365 | const enum hrtimer_mode mode, int wakeup); | |
366 | ||
c0a31329 TG |
367 | extern int hrtimer_cancel(struct hrtimer *timer); |
368 | extern int hrtimer_try_to_cancel(struct hrtimer *timer); | |
369 | ||
63ca243b AV |
370 | static inline int hrtimer_start_expires(struct hrtimer *timer, |
371 | enum hrtimer_mode mode) | |
372 | { | |
da8f2e17 AV |
373 | unsigned long delta; |
374 | ktime_t soft, hard; | |
375 | soft = hrtimer_get_softexpires(timer); | |
376 | hard = hrtimer_get_expires(timer); | |
377 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
4ce105d3 | 378 | return hrtimer_start_range_ns(timer, soft, delta, mode); |
63ca243b AV |
379 | } |
380 | ||
c9cb2e3d TG |
381 | static inline int hrtimer_restart(struct hrtimer *timer) |
382 | { | |
654c8e0b | 383 | return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); |
c9cb2e3d | 384 | } |
c0a31329 TG |
385 | |
386 | /* Query timers: */ | |
387 | extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); | |
c0a31329 | 388 | |
69239749 | 389 | extern ktime_t hrtimer_get_next_event(void); |
69239749 | 390 | |
303e967f | 391 | /* |
53370d2e TG |
392 | * A timer is active, when it is enqueued into the rbtree or the |
393 | * callback function is running or it's in the state of being migrated | |
394 | * to another cpu. | |
303e967f | 395 | */ |
c0a31329 TG |
396 | static inline int hrtimer_active(const struct hrtimer *timer) |
397 | { | |
303e967f | 398 | return timer->state != HRTIMER_STATE_INACTIVE; |
c0a31329 TG |
399 | } |
400 | ||
54cdfdb4 TG |
401 | /* |
402 | * Helper function to check, whether the timer is on one of the queues | |
403 | */ | |
404 | static inline int hrtimer_is_queued(struct hrtimer *timer) | |
405 | { | |
ca109491 | 406 | return timer->state & HRTIMER_STATE_ENQUEUED; |
54cdfdb4 TG |
407 | } |
408 | ||
4346f654 OH |
409 | /* |
410 | * Helper function to check, whether the timer is running the callback | |
411 | * function | |
412 | */ | |
413 | static inline int hrtimer_callback_running(struct hrtimer *timer) | |
414 | { | |
415 | return timer->state & HRTIMER_STATE_CALLBACK; | |
416 | } | |
417 | ||
c0a31329 | 418 | /* Forward a hrtimer so it expires after now: */ |
4d672e7a | 419 | extern u64 |
44f21475 | 420 | hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); |
c0a31329 | 421 | |
91e5a217 TG |
422 | /** |
423 | * hrtimer_forward_now - forward the timer expiry so it expires after now | |
424 | * @timer: hrtimer to forward | |
425 | * @interval: the interval to forward | |
426 | * | |
427 | * Forward the timer expiry so it will expire after the current time | |
428 | * of the hrtimer clock base. Returns the number of overruns. | |
429 | * | |
430 | * Can be safely called from the callback function of @timer. If | |
431 | * called from other contexts @timer must neither be enqueued nor | |
432 | * running the callback and the caller needs to take care of | |
433 | * serialization. | |
434 | * | |
435 | * Note: This only updates the timer expiry value and does not requeue | |
436 | * the timer. | |
437 | */ | |
4d672e7a DL |
438 | static inline u64 hrtimer_forward_now(struct hrtimer *timer, |
439 | ktime_t interval) | |
5e05ad7d DL |
440 | { |
441 | return hrtimer_forward(timer, timer->base->get_time(), interval); | |
442 | } | |
443 | ||
10c94ec1 TG |
444 | /* Precise sleep: */ |
445 | extern long hrtimer_nanosleep(struct timespec *rqtp, | |
080344b9 | 446 | struct timespec __user *rmtp, |
10c94ec1 TG |
447 | const enum hrtimer_mode mode, |
448 | const clockid_t clockid); | |
1711ef38 | 449 | extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); |
10c94ec1 | 450 | |
00362e33 TG |
451 | extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, |
452 | struct task_struct *tsk); | |
453 | ||
654c8e0b AV |
454 | extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, |
455 | const enum hrtimer_mode mode); | |
351b3f7a CE |
456 | extern int schedule_hrtimeout_range_clock(ktime_t *expires, |
457 | unsigned long delta, const enum hrtimer_mode mode, int clock); | |
7bb67439 AV |
458 | extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); |
459 | ||
c0a31329 TG |
460 | /* Soft interrupt function to run the hrtimer queues: */ |
461 | extern void hrtimer_run_queues(void); | |
d3d74453 | 462 | extern void hrtimer_run_pending(void); |
c0a31329 TG |
463 | |
464 | /* Bootup initialization: */ | |
465 | extern void __init hrtimers_init(void); | |
466 | ||
88ad0bf6 IM |
467 | /* Show pending timers: */ |
468 | extern void sysrq_timer_list_show(void); | |
469 | ||
c0a31329 | 470 | #endif |