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Commit | Line | Data |
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58687acb DZ |
1 | /* |
2 | * Detect hard and soft lockups on a system | |
3 | * | |
4 | * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc. | |
5 | * | |
6 | * this code detects hard lockups: incidents in where on a CPU | |
7 | * the kernel does not respond to anything except NMI. | |
8 | * | |
9 | * Note: Most of this code is borrowed heavily from softlockup.c, | |
10 | * so thanks to Ingo for the initial implementation. | |
11 | * Some chunks also taken from arch/x86/kernel/apic/nmi.c, thanks | |
12 | * to those contributors as well. | |
13 | */ | |
14 | ||
15 | #include <linux/mm.h> | |
16 | #include <linux/cpu.h> | |
17 | #include <linux/nmi.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/freezer.h> | |
21 | #include <linux/kthread.h> | |
22 | #include <linux/lockdep.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/sysctl.h> | |
26 | ||
27 | #include <asm/irq_regs.h> | |
28 | #include <linux/perf_event.h> | |
29 | ||
4135038a | 30 | int watchdog_enabled = 1; |
58687acb DZ |
31 | int __read_mostly softlockup_thresh = 60; |
32 | ||
33 | static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); | |
34 | static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog); | |
35 | static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer); | |
36 | static DEFINE_PER_CPU(bool, softlockup_touch_sync); | |
58687acb | 37 | static DEFINE_PER_CPU(bool, soft_watchdog_warn); |
23637d47 | 38 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
cafcd80d DZ |
39 | static DEFINE_PER_CPU(bool, hard_watchdog_warn); |
40 | static DEFINE_PER_CPU(bool, watchdog_nmi_touch); | |
58687acb DZ |
41 | static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts); |
42 | static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved); | |
43 | static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); | |
44 | #endif | |
45 | ||
58687acb DZ |
46 | /* boot commands */ |
47 | /* | |
48 | * Should we panic when a soft-lockup or hard-lockup occurs: | |
49 | */ | |
23637d47 | 50 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
58687acb DZ |
51 | static int hardlockup_panic; |
52 | ||
53 | static int __init hardlockup_panic_setup(char *str) | |
54 | { | |
55 | if (!strncmp(str, "panic", 5)) | |
56 | hardlockup_panic = 1; | |
5dc30558 | 57 | else if (!strncmp(str, "0", 1)) |
4135038a | 58 | watchdog_enabled = 0; |
58687acb DZ |
59 | return 1; |
60 | } | |
61 | __setup("nmi_watchdog=", hardlockup_panic_setup); | |
62 | #endif | |
63 | ||
64 | unsigned int __read_mostly softlockup_panic = | |
65 | CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; | |
66 | ||
67 | static int __init softlockup_panic_setup(char *str) | |
68 | { | |
69 | softlockup_panic = simple_strtoul(str, NULL, 0); | |
70 | ||
71 | return 1; | |
72 | } | |
73 | __setup("softlockup_panic=", softlockup_panic_setup); | |
74 | ||
75 | static int __init nowatchdog_setup(char *str) | |
76 | { | |
4135038a | 77 | watchdog_enabled = 0; |
58687acb DZ |
78 | return 1; |
79 | } | |
80 | __setup("nowatchdog", nowatchdog_setup); | |
81 | ||
82 | /* deprecated */ | |
83 | static int __init nosoftlockup_setup(char *str) | |
84 | { | |
4135038a | 85 | watchdog_enabled = 0; |
58687acb DZ |
86 | return 1; |
87 | } | |
88 | __setup("nosoftlockup", nosoftlockup_setup); | |
89 | /* */ | |
90 | ||
91 | ||
92 | /* | |
93 | * Returns seconds, approximately. We don't need nanosecond | |
94 | * resolution, and we don't need to waste time with a big divide when | |
95 | * 2^30ns == 1.074s. | |
96 | */ | |
97 | static unsigned long get_timestamp(int this_cpu) | |
98 | { | |
99 | return cpu_clock(this_cpu) >> 30LL; /* 2^30 ~= 10^9 */ | |
100 | } | |
101 | ||
102 | static unsigned long get_sample_period(void) | |
103 | { | |
104 | /* | |
105 | * convert softlockup_thresh from seconds to ns | |
106 | * the divide by 5 is to give hrtimer 5 chances to | |
107 | * increment before the hardlockup detector generates | |
108 | * a warning | |
109 | */ | |
110 | return softlockup_thresh / 5 * NSEC_PER_SEC; | |
111 | } | |
112 | ||
113 | /* Commands for resetting the watchdog */ | |
114 | static void __touch_watchdog(void) | |
115 | { | |
26e09c6e | 116 | int this_cpu = smp_processor_id(); |
58687acb | 117 | |
909ea964 | 118 | __this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu)); |
58687acb DZ |
119 | } |
120 | ||
332fbdbc | 121 | void touch_softlockup_watchdog(void) |
58687acb | 122 | { |
909ea964 | 123 | __this_cpu_write(watchdog_touch_ts, 0); |
58687acb | 124 | } |
0167c781 | 125 | EXPORT_SYMBOL(touch_softlockup_watchdog); |
58687acb | 126 | |
332fbdbc | 127 | void touch_all_softlockup_watchdogs(void) |
58687acb DZ |
128 | { |
129 | int cpu; | |
130 | ||
131 | /* | |
132 | * this is done lockless | |
133 | * do we care if a 0 races with a timestamp? | |
134 | * all it means is the softlock check starts one cycle later | |
135 | */ | |
136 | for_each_online_cpu(cpu) | |
137 | per_cpu(watchdog_touch_ts, cpu) = 0; | |
138 | } | |
139 | ||
cafcd80d | 140 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
58687acb DZ |
141 | void touch_nmi_watchdog(void) |
142 | { | |
68d3f1d8 DZ |
143 | if (watchdog_enabled) { |
144 | unsigned cpu; | |
145 | ||
146 | for_each_present_cpu(cpu) { | |
147 | if (per_cpu(watchdog_nmi_touch, cpu) != true) | |
148 | per_cpu(watchdog_nmi_touch, cpu) = true; | |
149 | } | |
150 | } | |
332fbdbc | 151 | touch_softlockup_watchdog(); |
58687acb DZ |
152 | } |
153 | EXPORT_SYMBOL(touch_nmi_watchdog); | |
154 | ||
cafcd80d DZ |
155 | #endif |
156 | ||
58687acb DZ |
157 | void touch_softlockup_watchdog_sync(void) |
158 | { | |
159 | __raw_get_cpu_var(softlockup_touch_sync) = true; | |
160 | __raw_get_cpu_var(watchdog_touch_ts) = 0; | |
161 | } | |
162 | ||
23637d47 | 163 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
58687acb | 164 | /* watchdog detector functions */ |
26e09c6e | 165 | static int is_hardlockup(void) |
58687acb | 166 | { |
909ea964 | 167 | unsigned long hrint = __this_cpu_read(hrtimer_interrupts); |
58687acb | 168 | |
909ea964 | 169 | if (__this_cpu_read(hrtimer_interrupts_saved) == hrint) |
58687acb DZ |
170 | return 1; |
171 | ||
909ea964 | 172 | __this_cpu_write(hrtimer_interrupts_saved, hrint); |
58687acb DZ |
173 | return 0; |
174 | } | |
175 | #endif | |
176 | ||
26e09c6e | 177 | static int is_softlockup(unsigned long touch_ts) |
58687acb | 178 | { |
26e09c6e | 179 | unsigned long now = get_timestamp(smp_processor_id()); |
58687acb DZ |
180 | |
181 | /* Warn about unreasonable delays: */ | |
182 | if (time_after(now, touch_ts + softlockup_thresh)) | |
183 | return now - touch_ts; | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
23637d47 | 188 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
58687acb DZ |
189 | static struct perf_event_attr wd_hw_attr = { |
190 | .type = PERF_TYPE_HARDWARE, | |
191 | .config = PERF_COUNT_HW_CPU_CYCLES, | |
192 | .size = sizeof(struct perf_event_attr), | |
193 | .pinned = 1, | |
194 | .disabled = 1, | |
195 | }; | |
196 | ||
197 | /* Callback function for perf event subsystem */ | |
277b1998 | 198 | static void watchdog_overflow_callback(struct perf_event *event, int nmi, |
58687acb DZ |
199 | struct perf_sample_data *data, |
200 | struct pt_regs *regs) | |
201 | { | |
c6db67cd PZ |
202 | /* Ensure the watchdog never gets throttled */ |
203 | event->hw.interrupts = 0; | |
204 | ||
909ea964 CL |
205 | if (__this_cpu_read(watchdog_nmi_touch) == true) { |
206 | __this_cpu_write(watchdog_nmi_touch, false); | |
58687acb DZ |
207 | return; |
208 | } | |
209 | ||
210 | /* check for a hardlockup | |
211 | * This is done by making sure our timer interrupt | |
212 | * is incrementing. The timer interrupt should have | |
213 | * fired multiple times before we overflow'd. If it hasn't | |
214 | * then this is a good indication the cpu is stuck | |
215 | */ | |
26e09c6e DZ |
216 | if (is_hardlockup()) { |
217 | int this_cpu = smp_processor_id(); | |
218 | ||
58687acb | 219 | /* only print hardlockups once */ |
909ea964 | 220 | if (__this_cpu_read(hard_watchdog_warn) == true) |
58687acb DZ |
221 | return; |
222 | ||
223 | if (hardlockup_panic) | |
224 | panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu); | |
225 | else | |
226 | WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu); | |
227 | ||
909ea964 | 228 | __this_cpu_write(hard_watchdog_warn, true); |
58687acb DZ |
229 | return; |
230 | } | |
231 | ||
909ea964 | 232 | __this_cpu_write(hard_watchdog_warn, false); |
58687acb DZ |
233 | return; |
234 | } | |
235 | static void watchdog_interrupt_count(void) | |
236 | { | |
909ea964 | 237 | __this_cpu_inc(hrtimer_interrupts); |
58687acb DZ |
238 | } |
239 | #else | |
240 | static inline void watchdog_interrupt_count(void) { return; } | |
23637d47 | 241 | #endif /* CONFIG_HARDLOCKUP_DETECTOR */ |
58687acb DZ |
242 | |
243 | /* watchdog kicker functions */ | |
244 | static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) | |
245 | { | |
909ea964 | 246 | unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts); |
58687acb DZ |
247 | struct pt_regs *regs = get_irq_regs(); |
248 | int duration; | |
249 | ||
250 | /* kick the hardlockup detector */ | |
251 | watchdog_interrupt_count(); | |
252 | ||
253 | /* kick the softlockup detector */ | |
909ea964 | 254 | wake_up_process(__this_cpu_read(softlockup_watchdog)); |
58687acb DZ |
255 | |
256 | /* .. and repeat */ | |
257 | hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period())); | |
258 | ||
259 | if (touch_ts == 0) { | |
909ea964 | 260 | if (unlikely(__this_cpu_read(softlockup_touch_sync))) { |
58687acb DZ |
261 | /* |
262 | * If the time stamp was touched atomically | |
263 | * make sure the scheduler tick is up to date. | |
264 | */ | |
909ea964 | 265 | __this_cpu_write(softlockup_touch_sync, false); |
58687acb DZ |
266 | sched_clock_tick(); |
267 | } | |
268 | __touch_watchdog(); | |
269 | return HRTIMER_RESTART; | |
270 | } | |
271 | ||
272 | /* check for a softlockup | |
273 | * This is done by making sure a high priority task is | |
274 | * being scheduled. The task touches the watchdog to | |
275 | * indicate it is getting cpu time. If it hasn't then | |
276 | * this is a good indication some task is hogging the cpu | |
277 | */ | |
26e09c6e | 278 | duration = is_softlockup(touch_ts); |
58687acb DZ |
279 | if (unlikely(duration)) { |
280 | /* only warn once */ | |
909ea964 | 281 | if (__this_cpu_read(soft_watchdog_warn) == true) |
58687acb DZ |
282 | return HRTIMER_RESTART; |
283 | ||
284 | printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", | |
26e09c6e | 285 | smp_processor_id(), duration, |
58687acb DZ |
286 | current->comm, task_pid_nr(current)); |
287 | print_modules(); | |
288 | print_irqtrace_events(current); | |
289 | if (regs) | |
290 | show_regs(regs); | |
291 | else | |
292 | dump_stack(); | |
293 | ||
294 | if (softlockup_panic) | |
295 | panic("softlockup: hung tasks"); | |
909ea964 | 296 | __this_cpu_write(soft_watchdog_warn, true); |
58687acb | 297 | } else |
909ea964 | 298 | __this_cpu_write(soft_watchdog_warn, false); |
58687acb DZ |
299 | |
300 | return HRTIMER_RESTART; | |
301 | } | |
302 | ||
303 | ||
304 | /* | |
305 | * The watchdog thread - touches the timestamp. | |
306 | */ | |
26e09c6e | 307 | static int watchdog(void *unused) |
58687acb | 308 | { |
fe7de49f | 309 | static struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; |
26e09c6e | 310 | struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer); |
58687acb DZ |
311 | |
312 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
313 | ||
314 | /* initialize timestamp */ | |
315 | __touch_watchdog(); | |
316 | ||
317 | /* kick off the timer for the hardlockup detector */ | |
318 | /* done here because hrtimer_start can only pin to smp_processor_id() */ | |
319 | hrtimer_start(hrtimer, ns_to_ktime(get_sample_period()), | |
320 | HRTIMER_MODE_REL_PINNED); | |
321 | ||
322 | set_current_state(TASK_INTERRUPTIBLE); | |
323 | /* | |
324 | * Run briefly once per second to reset the softlockup timestamp. | |
325 | * If this gets delayed for more than 60 seconds then the | |
26e09c6e | 326 | * debug-printout triggers in watchdog_timer_fn(). |
58687acb DZ |
327 | */ |
328 | while (!kthread_should_stop()) { | |
329 | __touch_watchdog(); | |
330 | schedule(); | |
331 | ||
332 | if (kthread_should_stop()) | |
333 | break; | |
334 | ||
335 | set_current_state(TASK_INTERRUPTIBLE); | |
336 | } | |
337 | __set_current_state(TASK_RUNNING); | |
338 | ||
339 | return 0; | |
340 | } | |
341 | ||
342 | ||
23637d47 | 343 | #ifdef CONFIG_HARDLOCKUP_DETECTOR |
58687acb DZ |
344 | static int watchdog_nmi_enable(int cpu) |
345 | { | |
346 | struct perf_event_attr *wd_attr; | |
347 | struct perf_event *event = per_cpu(watchdog_ev, cpu); | |
348 | ||
349 | /* is it already setup and enabled? */ | |
350 | if (event && event->state > PERF_EVENT_STATE_OFF) | |
351 | goto out; | |
352 | ||
353 | /* it is setup but not enabled */ | |
354 | if (event != NULL) | |
355 | goto out_enable; | |
356 | ||
357 | /* Try to register using hardware perf events */ | |
358 | wd_attr = &wd_hw_attr; | |
359 | wd_attr->sample_period = hw_nmi_get_sample_period(); | |
38a81da2 | 360 | event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback); |
58687acb DZ |
361 | if (!IS_ERR(event)) { |
362 | printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n"); | |
363 | goto out_save; | |
364 | } | |
365 | ||
5651f7f4 DZ |
366 | |
367 | /* vary the KERN level based on the returned errno */ | |
368 | if (PTR_ERR(event) == -EOPNOTSUPP) | |
369 | printk(KERN_INFO "NMI watchdog disabled (cpu%i): not supported (no LAPIC?)\n", cpu); | |
370 | else if (PTR_ERR(event) == -ENOENT) | |
371 | printk(KERN_WARNING "NMI watchdog disabled (cpu%i): hardware events not enabled\n", cpu); | |
372 | else | |
373 | printk(KERN_ERR "NMI watchdog disabled (cpu%i): unable to create perf event: %ld\n", cpu, PTR_ERR(event)); | |
eac24335 | 374 | return PTR_ERR(event); |
58687acb DZ |
375 | |
376 | /* success path */ | |
377 | out_save: | |
378 | per_cpu(watchdog_ev, cpu) = event; | |
379 | out_enable: | |
380 | perf_event_enable(per_cpu(watchdog_ev, cpu)); | |
381 | out: | |
382 | return 0; | |
383 | } | |
384 | ||
385 | static void watchdog_nmi_disable(int cpu) | |
386 | { | |
387 | struct perf_event *event = per_cpu(watchdog_ev, cpu); | |
388 | ||
389 | if (event) { | |
390 | perf_event_disable(event); | |
391 | per_cpu(watchdog_ev, cpu) = NULL; | |
392 | ||
393 | /* should be in cleanup, but blocks oprofile */ | |
394 | perf_event_release_kernel(event); | |
395 | } | |
396 | return; | |
397 | } | |
398 | #else | |
399 | static int watchdog_nmi_enable(int cpu) { return 0; } | |
400 | static void watchdog_nmi_disable(int cpu) { return; } | |
23637d47 | 401 | #endif /* CONFIG_HARDLOCKUP_DETECTOR */ |
58687acb DZ |
402 | |
403 | /* prepare/enable/disable routines */ | |
404 | static int watchdog_prepare_cpu(int cpu) | |
405 | { | |
406 | struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu); | |
407 | ||
408 | WARN_ON(per_cpu(softlockup_watchdog, cpu)); | |
409 | hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
410 | hrtimer->function = watchdog_timer_fn; | |
411 | ||
412 | return 0; | |
413 | } | |
414 | ||
415 | static int watchdog_enable(int cpu) | |
416 | { | |
417 | struct task_struct *p = per_cpu(softlockup_watchdog, cpu); | |
eac24335 | 418 | int err; |
58687acb DZ |
419 | |
420 | /* enable the perf event */ | |
eac24335 AM |
421 | err = watchdog_nmi_enable(cpu); |
422 | if (err) | |
423 | return err; | |
58687acb DZ |
424 | |
425 | /* create the watchdog thread */ | |
426 | if (!p) { | |
427 | p = kthread_create(watchdog, (void *)(unsigned long)cpu, "watchdog/%d", cpu); | |
428 | if (IS_ERR(p)) { | |
429 | printk(KERN_ERR "softlockup watchdog for %i failed\n", cpu); | |
eac24335 | 430 | return PTR_ERR(p); |
58687acb DZ |
431 | } |
432 | kthread_bind(p, cpu); | |
433 | per_cpu(watchdog_touch_ts, cpu) = 0; | |
434 | per_cpu(softlockup_watchdog, cpu) = p; | |
435 | wake_up_process(p); | |
436 | } | |
437 | ||
438 | return 0; | |
439 | } | |
440 | ||
441 | static void watchdog_disable(int cpu) | |
442 | { | |
443 | struct task_struct *p = per_cpu(softlockup_watchdog, cpu); | |
444 | struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu); | |
445 | ||
446 | /* | |
447 | * cancel the timer first to stop incrementing the stats | |
448 | * and waking up the kthread | |
449 | */ | |
450 | hrtimer_cancel(hrtimer); | |
451 | ||
452 | /* disable the perf event */ | |
453 | watchdog_nmi_disable(cpu); | |
454 | ||
455 | /* stop the watchdog thread */ | |
456 | if (p) { | |
457 | per_cpu(softlockup_watchdog, cpu) = NULL; | |
458 | kthread_stop(p); | |
459 | } | |
58687acb DZ |
460 | } |
461 | ||
462 | static void watchdog_enable_all_cpus(void) | |
463 | { | |
464 | int cpu; | |
39735766 MS |
465 | |
466 | watchdog_enabled = 0; | |
58687acb DZ |
467 | |
468 | for_each_online_cpu(cpu) | |
39735766 MS |
469 | if (!watchdog_enable(cpu)) |
470 | /* if any cpu succeeds, watchdog is considered | |
471 | enabled for the system */ | |
472 | watchdog_enabled = 1; | |
58687acb | 473 | |
39735766 | 474 | if (!watchdog_enabled) |
58687acb DZ |
475 | printk(KERN_ERR "watchdog: failed to be enabled on some cpus\n"); |
476 | ||
477 | } | |
478 | ||
479 | static void watchdog_disable_all_cpus(void) | |
480 | { | |
481 | int cpu; | |
482 | ||
483 | for_each_online_cpu(cpu) | |
484 | watchdog_disable(cpu); | |
485 | ||
486 | /* if all watchdogs are disabled, then they are disabled for the system */ | |
487 | watchdog_enabled = 0; | |
488 | } | |
489 | ||
490 | ||
491 | /* sysctl functions */ | |
492 | #ifdef CONFIG_SYSCTL | |
493 | /* | |
494 | * proc handler for /proc/sys/kernel/nmi_watchdog | |
495 | */ | |
496 | ||
497 | int proc_dowatchdog_enabled(struct ctl_table *table, int write, | |
498 | void __user *buffer, size_t *length, loff_t *ppos) | |
499 | { | |
500 | proc_dointvec(table, write, buffer, length, ppos); | |
501 | ||
9ffdc6c3 MS |
502 | if (write) { |
503 | if (watchdog_enabled) | |
504 | watchdog_enable_all_cpus(); | |
505 | else | |
506 | watchdog_disable_all_cpus(); | |
507 | } | |
58687acb DZ |
508 | return 0; |
509 | } | |
510 | ||
511 | int proc_dowatchdog_thresh(struct ctl_table *table, int write, | |
512 | void __user *buffer, | |
513 | size_t *lenp, loff_t *ppos) | |
514 | { | |
515 | return proc_dointvec_minmax(table, write, buffer, lenp, ppos); | |
516 | } | |
58687acb DZ |
517 | #endif /* CONFIG_SYSCTL */ |
518 | ||
519 | ||
520 | /* | |
521 | * Create/destroy watchdog threads as CPUs come and go: | |
522 | */ | |
523 | static int __cpuinit | |
524 | cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
525 | { | |
526 | int hotcpu = (unsigned long)hcpu; | |
eac24335 | 527 | int err = 0; |
58687acb DZ |
528 | |
529 | switch (action) { | |
530 | case CPU_UP_PREPARE: | |
531 | case CPU_UP_PREPARE_FROZEN: | |
eac24335 | 532 | err = watchdog_prepare_cpu(hotcpu); |
58687acb DZ |
533 | break; |
534 | case CPU_ONLINE: | |
535 | case CPU_ONLINE_FROZEN: | |
4135038a MS |
536 | if (watchdog_enabled) |
537 | err = watchdog_enable(hotcpu); | |
58687acb DZ |
538 | break; |
539 | #ifdef CONFIG_HOTPLUG_CPU | |
540 | case CPU_UP_CANCELED: | |
541 | case CPU_UP_CANCELED_FROZEN: | |
542 | watchdog_disable(hotcpu); | |
543 | break; | |
544 | case CPU_DEAD: | |
545 | case CPU_DEAD_FROZEN: | |
546 | watchdog_disable(hotcpu); | |
547 | break; | |
548 | #endif /* CONFIG_HOTPLUG_CPU */ | |
549 | } | |
eac24335 | 550 | return notifier_from_errno(err); |
58687acb DZ |
551 | } |
552 | ||
553 | static struct notifier_block __cpuinitdata cpu_nfb = { | |
554 | .notifier_call = cpu_callback | |
555 | }; | |
556 | ||
004417a6 | 557 | void __init lockup_detector_init(void) |
58687acb DZ |
558 | { |
559 | void *cpu = (void *)(long)smp_processor_id(); | |
560 | int err; | |
561 | ||
58687acb | 562 | err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); |
eac24335 | 563 | WARN_ON(notifier_to_errno(err)); |
58687acb DZ |
564 | |
565 | cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); | |
566 | register_cpu_notifier(&cpu_nfb); | |
567 | ||
004417a6 | 568 | return; |
58687acb | 569 | } |