xref: /linux/kernel/sched/debug.c (revision 99d2592023e5d0a31f5f5a83c694df48239a1e6c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * kernel/sched/debug.c
4  *
5  * Print the CFS rbtree and other debugging details
6  *
7  * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
8  */
9 #include <linux/debugfs.h>
10 #include <linux/nmi.h>
11 #include "sched.h"
12 
13 /*
14  * This allows printing both to /sys/kernel/debug/sched/debug and
15  * to the console
16  */
17 #define SEQ_printf(m, x...)			\
18  do {						\
19 	if (m)					\
20 		seq_printf(m, x);		\
21 	else					\
22 		pr_cont(x);			\
23  } while (0)
24 
25 /*
26  * Ease the printing of nsec fields:
27  */
28 static long long nsec_high(unsigned long long nsec)
29 {
30 	if ((long long)nsec < 0) {
31 		nsec = -nsec;
32 		do_div(nsec, 1000000);
33 		return -nsec;
34 	}
35 	do_div(nsec, 1000000);
36 
37 	return nsec;
38 }
39 
40 static unsigned long nsec_low(unsigned long long nsec)
41 {
42 	if ((long long)nsec < 0)
43 		nsec = -nsec;
44 
45 	return do_div(nsec, 1000000);
46 }
47 
48 #define SPLIT_NS(x) nsec_high(x), nsec_low(x)
49 
50 #define SCHED_FEAT(name, enabled)	\
51 	#name ,
52 
53 static const char * const sched_feat_names[] = {
54 #include "features.h"
55 };
56 
57 #undef SCHED_FEAT
58 
59 static int sched_feat_show(struct seq_file *m, void *v)
60 {
61 	int i;
62 
63 	for (i = 0; i < __SCHED_FEAT_NR; i++) {
64 		if (!(sysctl_sched_features & (1UL << i)))
65 			seq_puts(m, "NO_");
66 		seq_printf(m, "%s ", sched_feat_names[i]);
67 	}
68 	seq_puts(m, "\n");
69 
70 	return 0;
71 }
72 
73 #ifdef CONFIG_JUMP_LABEL
74 
75 #define jump_label_key__true  STATIC_KEY_INIT_TRUE
76 #define jump_label_key__false STATIC_KEY_INIT_FALSE
77 
78 #define SCHED_FEAT(name, enabled)	\
79 	jump_label_key__##enabled ,
80 
81 struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
82 #include "features.h"
83 };
84 
85 #undef SCHED_FEAT
86 
87 static void sched_feat_disable(int i)
88 {
89 	static_key_disable_cpuslocked(&sched_feat_keys[i]);
90 }
91 
92 static void sched_feat_enable(int i)
93 {
94 	static_key_enable_cpuslocked(&sched_feat_keys[i]);
95 }
96 #else /* !CONFIG_JUMP_LABEL: */
97 static void sched_feat_disable(int i) { };
98 static void sched_feat_enable(int i) { };
99 #endif /* !CONFIG_JUMP_LABEL */
100 
101 static int sched_feat_set(char *cmp)
102 {
103 	int i;
104 	int neg = 0;
105 
106 	if (strncmp(cmp, "NO_", 3) == 0) {
107 		neg = 1;
108 		cmp += 3;
109 	}
110 
111 	i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp);
112 	if (i < 0)
113 		return i;
114 
115 	if (neg) {
116 		sysctl_sched_features &= ~(1UL << i);
117 		sched_feat_disable(i);
118 	} else {
119 		sysctl_sched_features |= (1UL << i);
120 		sched_feat_enable(i);
121 	}
122 
123 	return 0;
124 }
125 
126 static ssize_t
127 sched_feat_write(struct file *filp, const char __user *ubuf,
128 		size_t cnt, loff_t *ppos)
129 {
130 	char buf[64];
131 	char *cmp;
132 	int ret;
133 	struct inode *inode;
134 
135 	if (cnt > 63)
136 		cnt = 63;
137 
138 	if (copy_from_user(&buf, ubuf, cnt))
139 		return -EFAULT;
140 
141 	buf[cnt] = 0;
142 	cmp = strstrip(buf);
143 
144 	/* Ensure the static_key remains in a consistent state */
145 	inode = file_inode(filp);
146 	cpus_read_lock();
147 	inode_lock(inode);
148 	ret = sched_feat_set(cmp);
149 	inode_unlock(inode);
150 	cpus_read_unlock();
151 	if (ret < 0)
152 		return ret;
153 
154 	*ppos += cnt;
155 
156 	return cnt;
157 }
158 
159 static int sched_feat_open(struct inode *inode, struct file *filp)
160 {
161 	return single_open(filp, sched_feat_show, NULL);
162 }
163 
164 static const struct file_operations sched_feat_fops = {
165 	.open		= sched_feat_open,
166 	.write		= sched_feat_write,
167 	.read		= seq_read,
168 	.llseek		= seq_lseek,
169 	.release	= single_release,
170 };
171 
172 static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf,
173 				   size_t cnt, loff_t *ppos)
174 {
175 	unsigned int scaling;
176 	int ret;
177 
178 	ret = kstrtouint_from_user(ubuf, cnt, 10, &scaling);
179 	if (ret)
180 		return ret;
181 
182 	if (scaling >= SCHED_TUNABLESCALING_END)
183 		return -EINVAL;
184 
185 	sysctl_sched_tunable_scaling = scaling;
186 	if (sched_update_scaling())
187 		return -EINVAL;
188 
189 	*ppos += cnt;
190 	return cnt;
191 }
192 
193 static int sched_scaling_show(struct seq_file *m, void *v)
194 {
195 	seq_printf(m, "%d\n", sysctl_sched_tunable_scaling);
196 	return 0;
197 }
198 
199 static int sched_scaling_open(struct inode *inode, struct file *filp)
200 {
201 	return single_open(filp, sched_scaling_show, NULL);
202 }
203 
204 static const struct file_operations sched_scaling_fops = {
205 	.open		= sched_scaling_open,
206 	.write		= sched_scaling_write,
207 	.read		= seq_read,
208 	.llseek		= seq_lseek,
209 	.release	= single_release,
210 };
211 
212 #ifdef CONFIG_PREEMPT_DYNAMIC
213 
214 static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
215 				   size_t cnt, loff_t *ppos)
216 {
217 	char buf[16];
218 	int mode;
219 
220 	if (cnt > 15)
221 		cnt = 15;
222 
223 	if (copy_from_user(&buf, ubuf, cnt))
224 		return -EFAULT;
225 
226 	buf[cnt] = 0;
227 	mode = sched_dynamic_mode(strstrip(buf));
228 	if (mode < 0)
229 		return mode;
230 
231 	sched_dynamic_update(mode);
232 
233 	*ppos += cnt;
234 
235 	return cnt;
236 }
237 
238 static int sched_dynamic_show(struct seq_file *m, void *v)
239 {
240 	int i = (IS_ENABLED(CONFIG_PREEMPT_RT) || IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY)) * 2;
241 	int j;
242 
243 	/* Count entries in NULL terminated preempt_modes */
244 	for (j = 0; preempt_modes[j]; j++)
245 		;
246 	j -= !IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY);
247 
248 	for (; i < j; i++) {
249 		if (preempt_dynamic_mode == i)
250 			seq_puts(m, "(");
251 		seq_puts(m, preempt_modes[i]);
252 		if (preempt_dynamic_mode == i)
253 			seq_puts(m, ")");
254 
255 		seq_puts(m, " ");
256 	}
257 
258 	seq_puts(m, "\n");
259 	return 0;
260 }
261 
262 static int sched_dynamic_open(struct inode *inode, struct file *filp)
263 {
264 	return single_open(filp, sched_dynamic_show, NULL);
265 }
266 
267 static const struct file_operations sched_dynamic_fops = {
268 	.open		= sched_dynamic_open,
269 	.write		= sched_dynamic_write,
270 	.read		= seq_read,
271 	.llseek		= seq_lseek,
272 	.release	= single_release,
273 };
274 
275 #endif /* CONFIG_PREEMPT_DYNAMIC */
276 
277 __read_mostly bool sched_debug_verbose;
278 
279 static struct dentry           *sd_dentry;
280 
281 
282 static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
283 				  size_t cnt, loff_t *ppos)
284 {
285 	ssize_t result;
286 	bool orig;
287 
288 	cpus_read_lock();
289 	sched_domains_mutex_lock();
290 
291 	orig = sched_debug_verbose;
292 	result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
293 
294 	if (sched_debug_verbose && !orig)
295 		update_sched_domain_debugfs();
296 	else if (!sched_debug_verbose && orig) {
297 		debugfs_remove(sd_dentry);
298 		sd_dentry = NULL;
299 	}
300 
301 	sched_domains_mutex_unlock();
302 	cpus_read_unlock();
303 
304 	return result;
305 }
306 
307 static const struct file_operations sched_verbose_fops = {
308 	.read =         debugfs_read_file_bool,
309 	.write =        sched_verbose_write,
310 	.open =         simple_open,
311 	.llseek =       default_llseek,
312 };
313 
314 static const struct seq_operations sched_debug_sops;
315 
316 static int sched_debug_open(struct inode *inode, struct file *filp)
317 {
318 	return seq_open(filp, &sched_debug_sops);
319 }
320 
321 static const struct file_operations sched_debug_fops = {
322 	.open		= sched_debug_open,
323 	.read		= seq_read,
324 	.llseek		= seq_lseek,
325 	.release	= seq_release,
326 };
327 
328 enum dl_param {
329 	DL_RUNTIME = 0,
330 	DL_PERIOD,
331 };
332 
333 static unsigned long fair_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */
334 static unsigned long fair_server_period_min = (100) * NSEC_PER_USEC;     /* 100 us */
335 
336 static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubuf,
337 				       size_t cnt, loff_t *ppos, enum dl_param param)
338 {
339 	long cpu = (long) ((struct seq_file *) filp->private_data)->private;
340 	struct rq *rq = cpu_rq(cpu);
341 	u64 runtime, period;
342 	size_t err;
343 	int retval;
344 	u64 value;
345 
346 	err = kstrtoull_from_user(ubuf, cnt, 10, &value);
347 	if (err)
348 		return err;
349 
350 	scoped_guard (rq_lock_irqsave, rq) {
351 		runtime  = rq->fair_server.dl_runtime;
352 		period = rq->fair_server.dl_period;
353 
354 		switch (param) {
355 		case DL_RUNTIME:
356 			if (runtime == value)
357 				break;
358 			runtime = value;
359 			break;
360 		case DL_PERIOD:
361 			if (value == period)
362 				break;
363 			period = value;
364 			break;
365 		}
366 
367 		if (runtime > period ||
368 		    period > fair_server_period_max ||
369 		    period < fair_server_period_min) {
370 			return  -EINVAL;
371 		}
372 
373 		update_rq_clock(rq);
374 		dl_server_stop(&rq->fair_server);
375 
376 		retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
377 		if (retval)
378 			cnt = retval;
379 
380 		if (!runtime)
381 			printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n",
382 					cpu_of(rq));
383 
384 		if (rq->cfs.h_nr_queued)
385 			dl_server_start(&rq->fair_server);
386 	}
387 
388 	*ppos += cnt;
389 	return cnt;
390 }
391 
392 static size_t sched_fair_server_show(struct seq_file *m, void *v, enum dl_param param)
393 {
394 	unsigned long cpu = (unsigned long) m->private;
395 	struct rq *rq = cpu_rq(cpu);
396 	u64 value;
397 
398 	switch (param) {
399 	case DL_RUNTIME:
400 		value = rq->fair_server.dl_runtime;
401 		break;
402 	case DL_PERIOD:
403 		value = rq->fair_server.dl_period;
404 		break;
405 	}
406 
407 	seq_printf(m, "%llu\n", value);
408 	return 0;
409 
410 }
411 
412 static ssize_t
413 sched_fair_server_runtime_write(struct file *filp, const char __user *ubuf,
414 				size_t cnt, loff_t *ppos)
415 {
416 	return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_RUNTIME);
417 }
418 
419 static int sched_fair_server_runtime_show(struct seq_file *m, void *v)
420 {
421 	return sched_fair_server_show(m, v, DL_RUNTIME);
422 }
423 
424 static int sched_fair_server_runtime_open(struct inode *inode, struct file *filp)
425 {
426 	return single_open(filp, sched_fair_server_runtime_show, inode->i_private);
427 }
428 
429 static const struct file_operations fair_server_runtime_fops = {
430 	.open		= sched_fair_server_runtime_open,
431 	.write		= sched_fair_server_runtime_write,
432 	.read		= seq_read,
433 	.llseek		= seq_lseek,
434 	.release	= single_release,
435 };
436 
437 static ssize_t
438 sched_fair_server_period_write(struct file *filp, const char __user *ubuf,
439 			       size_t cnt, loff_t *ppos)
440 {
441 	return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_PERIOD);
442 }
443 
444 static int sched_fair_server_period_show(struct seq_file *m, void *v)
445 {
446 	return sched_fair_server_show(m, v, DL_PERIOD);
447 }
448 
449 static int sched_fair_server_period_open(struct inode *inode, struct file *filp)
450 {
451 	return single_open(filp, sched_fair_server_period_show, inode->i_private);
452 }
453 
454 static const struct file_operations fair_server_period_fops = {
455 	.open		= sched_fair_server_period_open,
456 	.write		= sched_fair_server_period_write,
457 	.read		= seq_read,
458 	.llseek		= seq_lseek,
459 	.release	= single_release,
460 };
461 
462 static struct dentry *debugfs_sched;
463 
464 static void debugfs_fair_server_init(void)
465 {
466 	struct dentry *d_fair;
467 	unsigned long cpu;
468 
469 	d_fair = debugfs_create_dir("fair_server", debugfs_sched);
470 	if (!d_fair)
471 		return;
472 
473 	for_each_possible_cpu(cpu) {
474 		struct dentry *d_cpu;
475 		char buf[32];
476 
477 		snprintf(buf, sizeof(buf), "cpu%lu", cpu);
478 		d_cpu = debugfs_create_dir(buf, d_fair);
479 
480 		debugfs_create_file("runtime", 0644, d_cpu, (void *) cpu, &fair_server_runtime_fops);
481 		debugfs_create_file("period", 0644, d_cpu, (void *) cpu, &fair_server_period_fops);
482 	}
483 }
484 
485 static __init int sched_init_debug(void)
486 {
487 	struct dentry __maybe_unused *numa;
488 
489 	debugfs_sched = debugfs_create_dir("sched", NULL);
490 
491 	debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
492 	debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops);
493 #ifdef CONFIG_PREEMPT_DYNAMIC
494 	debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
495 #endif
496 
497 	debugfs_create_u32("base_slice_ns", 0644, debugfs_sched, &sysctl_sched_base_slice);
498 
499 	debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms);
500 	debugfs_create_u32("latency_warn_once", 0644, debugfs_sched, &sysctl_resched_latency_warn_once);
501 
502 	debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops);
503 	debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);
504 	debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);
505 
506 	sched_domains_mutex_lock();
507 	update_sched_domain_debugfs();
508 	sched_domains_mutex_unlock();
509 
510 #ifdef CONFIG_NUMA_BALANCING
511 	numa = debugfs_create_dir("numa_balancing", debugfs_sched);
512 
513 	debugfs_create_u32("scan_delay_ms", 0644, numa, &sysctl_numa_balancing_scan_delay);
514 	debugfs_create_u32("scan_period_min_ms", 0644, numa, &sysctl_numa_balancing_scan_period_min);
515 	debugfs_create_u32("scan_period_max_ms", 0644, numa, &sysctl_numa_balancing_scan_period_max);
516 	debugfs_create_u32("scan_size_mb", 0644, numa, &sysctl_numa_balancing_scan_size);
517 	debugfs_create_u32("hot_threshold_ms", 0644, numa, &sysctl_numa_balancing_hot_threshold);
518 #endif /* CONFIG_NUMA_BALANCING */
519 
520 	debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops);
521 
522 	debugfs_fair_server_init();
523 
524 	return 0;
525 }
526 late_initcall(sched_init_debug);
527 
528 static cpumask_var_t		sd_sysctl_cpus;
529 
530 static int sd_flags_show(struct seq_file *m, void *v)
531 {
532 	unsigned long flags = *(unsigned int *)m->private;
533 	int idx;
534 
535 	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
536 		seq_puts(m, sd_flag_debug[idx].name);
537 		seq_puts(m, " ");
538 	}
539 	seq_puts(m, "\n");
540 
541 	return 0;
542 }
543 
544 static int sd_flags_open(struct inode *inode, struct file *file)
545 {
546 	return single_open(file, sd_flags_show, inode->i_private);
547 }
548 
549 static const struct file_operations sd_flags_fops = {
550 	.open		= sd_flags_open,
551 	.read		= seq_read,
552 	.llseek		= seq_lseek,
553 	.release	= single_release,
554 };
555 
556 static void register_sd(struct sched_domain *sd, struct dentry *parent)
557 {
558 #define SDM(type, mode, member)	\
559 	debugfs_create_##type(#member, mode, parent, &sd->member)
560 
561 	SDM(ulong, 0644, min_interval);
562 	SDM(ulong, 0644, max_interval);
563 	SDM(u64,   0644, max_newidle_lb_cost);
564 	SDM(u32,   0644, busy_factor);
565 	SDM(u32,   0644, imbalance_pct);
566 	SDM(u32,   0644, cache_nice_tries);
567 	SDM(str,   0444, name);
568 
569 #undef SDM
570 
571 	debugfs_create_file("flags", 0444, parent, &sd->flags, &sd_flags_fops);
572 	debugfs_create_file("groups_flags", 0444, parent, &sd->groups->flags, &sd_flags_fops);
573 	debugfs_create_u32("level", 0444, parent, (u32 *)&sd->level);
574 
575 	if (sd->flags & SD_ASYM_PACKING)
576 		debugfs_create_u32("group_asym_prefer_cpu", 0444, parent,
577 				   (u32 *)&sd->groups->asym_prefer_cpu);
578 }
579 
580 void update_sched_domain_debugfs(void)
581 {
582 	int cpu, i;
583 
584 	/*
585 	 * This can unfortunately be invoked before sched_debug_init() creates
586 	 * the debug directory. Don't touch sd_sysctl_cpus until then.
587 	 */
588 	if (!debugfs_sched)
589 		return;
590 
591 	if (!sched_debug_verbose)
592 		return;
593 
594 	if (!cpumask_available(sd_sysctl_cpus)) {
595 		if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
596 			return;
597 		cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
598 	}
599 
600 	if (!sd_dentry) {
601 		sd_dentry = debugfs_create_dir("domains", debugfs_sched);
602 
603 		/* rebuild sd_sysctl_cpus if empty since it gets cleared below */
604 		if (cpumask_empty(sd_sysctl_cpus))
605 			cpumask_copy(sd_sysctl_cpus, cpu_online_mask);
606 	}
607 
608 	for_each_cpu(cpu, sd_sysctl_cpus) {
609 		struct sched_domain *sd;
610 		struct dentry *d_cpu;
611 		char buf[32];
612 
613 		snprintf(buf, sizeof(buf), "cpu%d", cpu);
614 		debugfs_lookup_and_remove(buf, sd_dentry);
615 		d_cpu = debugfs_create_dir(buf, sd_dentry);
616 
617 		i = 0;
618 		for_each_domain(cpu, sd) {
619 			struct dentry *d_sd;
620 
621 			snprintf(buf, sizeof(buf), "domain%d", i);
622 			d_sd = debugfs_create_dir(buf, d_cpu);
623 
624 			register_sd(sd, d_sd);
625 			i++;
626 		}
627 
628 		__cpumask_clear_cpu(cpu, sd_sysctl_cpus);
629 	}
630 }
631 
632 void dirty_sched_domain_sysctl(int cpu)
633 {
634 	if (cpumask_available(sd_sysctl_cpus))
635 		__cpumask_set_cpu(cpu, sd_sysctl_cpus);
636 }
637 
638 #ifdef CONFIG_FAIR_GROUP_SCHED
639 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
640 {
641 	struct sched_entity *se = tg->se[cpu];
642 
643 #define P(F)		SEQ_printf(m, "  .%-30s: %lld\n",	#F, (long long)F)
644 #define P_SCHEDSTAT(F)	SEQ_printf(m, "  .%-30s: %lld\n",	\
645 		#F, (long long)schedstat_val(stats->F))
646 #define PN(F)		SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
647 #define PN_SCHEDSTAT(F)	SEQ_printf(m, "  .%-30s: %lld.%06ld\n", \
648 		#F, SPLIT_NS((long long)schedstat_val(stats->F)))
649 
650 	if (!se)
651 		return;
652 
653 	PN(se->exec_start);
654 	PN(se->vruntime);
655 	PN(se->sum_exec_runtime);
656 
657 	if (schedstat_enabled()) {
658 		struct sched_statistics *stats;
659 		stats = __schedstats_from_se(se);
660 
661 		PN_SCHEDSTAT(wait_start);
662 		PN_SCHEDSTAT(sleep_start);
663 		PN_SCHEDSTAT(block_start);
664 		PN_SCHEDSTAT(sleep_max);
665 		PN_SCHEDSTAT(block_max);
666 		PN_SCHEDSTAT(exec_max);
667 		PN_SCHEDSTAT(slice_max);
668 		PN_SCHEDSTAT(wait_max);
669 		PN_SCHEDSTAT(wait_sum);
670 		P_SCHEDSTAT(wait_count);
671 	}
672 
673 	P(se->load.weight);
674 	P(se->avg.load_avg);
675 	P(se->avg.util_avg);
676 	P(se->avg.runnable_avg);
677 
678 #undef PN_SCHEDSTAT
679 #undef PN
680 #undef P_SCHEDSTAT
681 #undef P
682 }
683 #endif /* CONFIG_FAIR_GROUP_SCHED */
684 
685 #ifdef CONFIG_CGROUP_SCHED
686 static DEFINE_SPINLOCK(sched_debug_lock);
687 static char group_path[PATH_MAX];
688 
689 static void task_group_path(struct task_group *tg, char *path, int plen)
690 {
691 	if (autogroup_path(tg, path, plen))
692 		return;
693 
694 	cgroup_path(tg->css.cgroup, path, plen);
695 }
696 
697 /*
698  * Only 1 SEQ_printf_task_group_path() caller can use the full length
699  * group_path[] for cgroup path. Other simultaneous callers will have
700  * to use a shorter stack buffer. A "..." suffix is appended at the end
701  * of the stack buffer so that it will show up in case the output length
702  * matches the given buffer size to indicate possible path name truncation.
703  */
704 #define SEQ_printf_task_group_path(m, tg, fmt...)			\
705 {									\
706 	if (spin_trylock(&sched_debug_lock)) {				\
707 		task_group_path(tg, group_path, sizeof(group_path));	\
708 		SEQ_printf(m, fmt, group_path);				\
709 		spin_unlock(&sched_debug_lock);				\
710 	} else {							\
711 		char buf[128];						\
712 		char *bufend = buf + sizeof(buf) - 3;			\
713 		task_group_path(tg, buf, bufend - buf);			\
714 		strcpy(bufend - 1, "...");				\
715 		SEQ_printf(m, fmt, buf);				\
716 	}								\
717 }
718 #endif
719 
720 static void
721 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
722 {
723 	if (task_current(rq, p))
724 		SEQ_printf(m, ">R");
725 	else
726 		SEQ_printf(m, " %c", task_state_to_char(p));
727 
728 	SEQ_printf(m, " %15s %5d %9Ld.%06ld   %c   %9Ld.%06ld %c %9Ld.%06ld %9Ld.%06ld %9Ld   %5d ",
729 		p->comm, task_pid_nr(p),
730 		SPLIT_NS(p->se.vruntime),
731 		entity_eligible(cfs_rq_of(&p->se), &p->se) ? 'E' : 'N',
732 		SPLIT_NS(p->se.deadline),
733 		p->se.custom_slice ? 'S' : ' ',
734 		SPLIT_NS(p->se.slice),
735 		SPLIT_NS(p->se.sum_exec_runtime),
736 		(long long)(p->nvcsw + p->nivcsw),
737 		p->prio);
738 
739 	SEQ_printf(m, "%9lld.%06ld %9lld.%06ld %9lld.%06ld",
740 		SPLIT_NS(schedstat_val_or_zero(p->stats.wait_sum)),
741 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)),
742 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime)));
743 
744 #ifdef CONFIG_NUMA_BALANCING
745 	SEQ_printf(m, "   %d      %d", task_node(p), task_numa_group_id(p));
746 #endif
747 #ifdef CONFIG_CGROUP_SCHED
748 	SEQ_printf_task_group_path(m, task_group(p), "        %s")
749 #endif
750 
751 	SEQ_printf(m, "\n");
752 }
753 
754 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
755 {
756 	struct task_struct *g, *p;
757 
758 	SEQ_printf(m, "\n");
759 	SEQ_printf(m, "runnable tasks:\n");
760 	SEQ_printf(m, " S            task   PID       vruntime   eligible    "
761 		   "deadline             slice          sum-exec      switches  "
762 		   "prio         wait-time        sum-sleep       sum-block"
763 #ifdef CONFIG_NUMA_BALANCING
764 		   "  node   group-id"
765 #endif
766 #ifdef CONFIG_CGROUP_SCHED
767 		   "  group-path"
768 #endif
769 		   "\n");
770 	SEQ_printf(m, "-------------------------------------------------------"
771 		   "------------------------------------------------------"
772 		   "------------------------------------------------------"
773 #ifdef CONFIG_NUMA_BALANCING
774 		   "--------------"
775 #endif
776 #ifdef CONFIG_CGROUP_SCHED
777 		   "--------------"
778 #endif
779 		   "\n");
780 
781 	rcu_read_lock();
782 	for_each_process_thread(g, p) {
783 		if (task_cpu(p) != rq_cpu)
784 			continue;
785 
786 		print_task(m, rq, p);
787 	}
788 	rcu_read_unlock();
789 }
790 
791 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
792 {
793 	s64 left_vruntime = -1, zero_vruntime, right_vruntime = -1, left_deadline = -1, spread;
794 	struct sched_entity *last, *first, *root;
795 	struct rq *rq = cpu_rq(cpu);
796 	unsigned long flags;
797 
798 #ifdef CONFIG_FAIR_GROUP_SCHED
799 	SEQ_printf(m, "\n");
800 	SEQ_printf_task_group_path(m, cfs_rq->tg, "cfs_rq[%d]:%s\n", cpu);
801 #else
802 	SEQ_printf(m, "\n");
803 	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
804 #endif
805 
806 	raw_spin_rq_lock_irqsave(rq, flags);
807 	root = __pick_root_entity(cfs_rq);
808 	if (root)
809 		left_vruntime = root->min_vruntime;
810 	first = __pick_first_entity(cfs_rq);
811 	if (first)
812 		left_deadline = first->deadline;
813 	last = __pick_last_entity(cfs_rq);
814 	if (last)
815 		right_vruntime = last->vruntime;
816 	zero_vruntime = cfs_rq->zero_vruntime;
817 	raw_spin_rq_unlock_irqrestore(rq, flags);
818 
819 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "left_deadline",
820 			SPLIT_NS(left_deadline));
821 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "left_vruntime",
822 			SPLIT_NS(left_vruntime));
823 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "zero_vruntime",
824 			SPLIT_NS(zero_vruntime));
825 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "avg_vruntime",
826 			SPLIT_NS(avg_vruntime(cfs_rq)));
827 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "right_vruntime",
828 			SPLIT_NS(right_vruntime));
829 	spread = right_vruntime - left_vruntime;
830 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
831 	SEQ_printf(m, "  .%-30s: %d\n", "nr_queued", cfs_rq->nr_queued);
832 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_runnable", cfs_rq->h_nr_runnable);
833 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_queued", cfs_rq->h_nr_queued);
834 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_idle", cfs_rq->h_nr_idle);
835 	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
836 	SEQ_printf(m, "  .%-30s: %lu\n", "load_avg",
837 			cfs_rq->avg.load_avg);
838 	SEQ_printf(m, "  .%-30s: %lu\n", "runnable_avg",
839 			cfs_rq->avg.runnable_avg);
840 	SEQ_printf(m, "  .%-30s: %lu\n", "util_avg",
841 			cfs_rq->avg.util_avg);
842 	SEQ_printf(m, "  .%-30s: %u\n", "util_est",
843 			cfs_rq->avg.util_est);
844 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.load_avg",
845 			cfs_rq->removed.load_avg);
846 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.util_avg",
847 			cfs_rq->removed.util_avg);
848 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.runnable_avg",
849 			cfs_rq->removed.runnable_avg);
850 #ifdef CONFIG_FAIR_GROUP_SCHED
851 	SEQ_printf(m, "  .%-30s: %lu\n", "tg_load_avg_contrib",
852 			cfs_rq->tg_load_avg_contrib);
853 	SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_avg",
854 			atomic_long_read(&cfs_rq->tg->load_avg));
855 #endif /* CONFIG_FAIR_GROUP_SCHED */
856 #ifdef CONFIG_CFS_BANDWIDTH
857 	SEQ_printf(m, "  .%-30s: %d\n", "throttled",
858 			cfs_rq->throttled);
859 	SEQ_printf(m, "  .%-30s: %d\n", "throttle_count",
860 			cfs_rq->throttle_count);
861 #endif
862 
863 #ifdef CONFIG_FAIR_GROUP_SCHED
864 	print_cfs_group_stats(m, cpu, cfs_rq->tg);
865 #endif
866 }
867 
868 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
869 {
870 #ifdef CONFIG_RT_GROUP_SCHED
871 	SEQ_printf(m, "\n");
872 	SEQ_printf_task_group_path(m, rt_rq->tg, "rt_rq[%d]:%s\n", cpu);
873 #else
874 	SEQ_printf(m, "\n");
875 	SEQ_printf(m, "rt_rq[%d]:\n", cpu);
876 #endif
877 
878 #define P(x) \
879 	SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
880 #define PU(x) \
881 	SEQ_printf(m, "  .%-30s: %lu\n", #x, (unsigned long)(rt_rq->x))
882 #define PN(x) \
883 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
884 
885 	PU(rt_nr_running);
886 
887 #ifdef CONFIG_RT_GROUP_SCHED
888 	P(rt_throttled);
889 	PN(rt_time);
890 	PN(rt_runtime);
891 #endif
892 
893 #undef PN
894 #undef PU
895 #undef P
896 }
897 
898 void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
899 {
900 	struct dl_bw *dl_bw;
901 
902 	SEQ_printf(m, "\n");
903 	SEQ_printf(m, "dl_rq[%d]:\n", cpu);
904 
905 #define PU(x) \
906 	SEQ_printf(m, "  .%-30s: %lu\n", #x, (unsigned long)(dl_rq->x))
907 
908 	PU(dl_nr_running);
909 	dl_bw = &cpu_rq(cpu)->rd->dl_bw;
910 	SEQ_printf(m, "  .%-30s: %lld\n", "dl_bw->bw", dl_bw->bw);
911 	SEQ_printf(m, "  .%-30s: %lld\n", "dl_bw->total_bw", dl_bw->total_bw);
912 
913 #undef PU
914 }
915 
916 static void print_cpu(struct seq_file *m, int cpu)
917 {
918 	struct rq *rq = cpu_rq(cpu);
919 
920 #ifdef CONFIG_X86
921 	{
922 		unsigned int freq = cpu_khz ? : 1;
923 
924 		SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
925 			   cpu, freq / 1000, (freq % 1000));
926 	}
927 #else /* !CONFIG_X86: */
928 	SEQ_printf(m, "cpu#%d\n", cpu);
929 #endif /* !CONFIG_X86 */
930 
931 #define P(x)								\
932 do {									\
933 	if (sizeof(rq->x) == 4)						\
934 		SEQ_printf(m, "  .%-30s: %d\n", #x, (int)(rq->x));	\
935 	else								\
936 		SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x));\
937 } while (0)
938 
939 #define PN(x) \
940 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
941 
942 	P(nr_running);
943 	P(nr_switches);
944 	P(nr_uninterruptible);
945 	PN(next_balance);
946 	SEQ_printf(m, "  .%-30s: %ld\n", "curr->pid", (long)(task_pid_nr(rq->curr)));
947 	PN(clock);
948 	PN(clock_task);
949 #undef P
950 #undef PN
951 
952 #define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);
953 	P64(avg_idle);
954 	P64(max_idle_balance_cost);
955 #undef P64
956 
957 #define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, schedstat_val(rq->n));
958 	if (schedstat_enabled()) {
959 		P(yld_count);
960 		P(sched_count);
961 		P(sched_goidle);
962 		P(ttwu_count);
963 		P(ttwu_local);
964 	}
965 #undef P
966 
967 	print_cfs_stats(m, cpu);
968 	print_rt_stats(m, cpu);
969 	print_dl_stats(m, cpu);
970 
971 	print_rq(m, rq, cpu);
972 	SEQ_printf(m, "\n");
973 }
974 
975 static const char *sched_tunable_scaling_names[] = {
976 	"none",
977 	"logarithmic",
978 	"linear"
979 };
980 
981 static void sched_debug_header(struct seq_file *m)
982 {
983 	u64 ktime, sched_clk, cpu_clk;
984 	unsigned long flags;
985 
986 	local_irq_save(flags);
987 	ktime = ktime_to_ns(ktime_get());
988 	sched_clk = sched_clock();
989 	cpu_clk = local_clock();
990 	local_irq_restore(flags);
991 
992 	SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n",
993 		init_utsname()->release,
994 		(int)strcspn(init_utsname()->version, " "),
995 		init_utsname()->version);
996 
997 #define P(x) \
998 	SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
999 #define PN(x) \
1000 	SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
1001 	PN(ktime);
1002 	PN(sched_clk);
1003 	PN(cpu_clk);
1004 	P(jiffies);
1005 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1006 	P(sched_clock_stable());
1007 #endif
1008 #undef PN
1009 #undef P
1010 
1011 	SEQ_printf(m, "\n");
1012 	SEQ_printf(m, "sysctl_sched\n");
1013 
1014 #define P(x) \
1015 	SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
1016 #define PN(x) \
1017 	SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
1018 	PN(sysctl_sched_base_slice);
1019 	P(sysctl_sched_features);
1020 #undef PN
1021 #undef P
1022 
1023 	SEQ_printf(m, "  .%-40s: %d (%s)\n",
1024 		"sysctl_sched_tunable_scaling",
1025 		sysctl_sched_tunable_scaling,
1026 		sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
1027 	SEQ_printf(m, "\n");
1028 }
1029 
1030 static int sched_debug_show(struct seq_file *m, void *v)
1031 {
1032 	int cpu = (unsigned long)(v - 2);
1033 
1034 	if (cpu != -1)
1035 		print_cpu(m, cpu);
1036 	else
1037 		sched_debug_header(m);
1038 
1039 	return 0;
1040 }
1041 
1042 void sysrq_sched_debug_show(void)
1043 {
1044 	int cpu;
1045 
1046 	sched_debug_header(NULL);
1047 	for_each_online_cpu(cpu) {
1048 		/*
1049 		 * Need to reset softlockup watchdogs on all CPUs, because
1050 		 * another CPU might be blocked waiting for us to process
1051 		 * an IPI or stop_machine.
1052 		 */
1053 		touch_nmi_watchdog();
1054 		touch_all_softlockup_watchdogs();
1055 		print_cpu(NULL, cpu);
1056 	}
1057 }
1058 
1059 /*
1060  * This iterator needs some explanation.
1061  * It returns 1 for the header position.
1062  * This means 2 is CPU 0.
1063  * In a hotplugged system some CPUs, including CPU 0, may be missing so we have
1064  * to use cpumask_* to iterate over the CPUs.
1065  */
1066 static void *sched_debug_start(struct seq_file *file, loff_t *offset)
1067 {
1068 	unsigned long n = *offset;
1069 
1070 	if (n == 0)
1071 		return (void *) 1;
1072 
1073 	n--;
1074 
1075 	if (n > 0)
1076 		n = cpumask_next(n - 1, cpu_online_mask);
1077 	else
1078 		n = cpumask_first(cpu_online_mask);
1079 
1080 	*offset = n + 1;
1081 
1082 	if (n < nr_cpu_ids)
1083 		return (void *)(unsigned long)(n + 2);
1084 
1085 	return NULL;
1086 }
1087 
1088 static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
1089 {
1090 	(*offset)++;
1091 	return sched_debug_start(file, offset);
1092 }
1093 
1094 static void sched_debug_stop(struct seq_file *file, void *data)
1095 {
1096 }
1097 
1098 static const struct seq_operations sched_debug_sops = {
1099 	.start		= sched_debug_start,
1100 	.next		= sched_debug_next,
1101 	.stop		= sched_debug_stop,
1102 	.show		= sched_debug_show,
1103 };
1104 
1105 #define __PS(S, F) SEQ_printf(m, "%-45s:%21Ld\n", S, (long long)(F))
1106 #define __P(F) __PS(#F, F)
1107 #define   P(F) __PS(#F, p->F)
1108 #define   PM(F, M) __PS(#F, p->F & (M))
1109 #define __PSN(S, F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", S, SPLIT_NS((long long)(F)))
1110 #define __PN(F) __PSN(#F, F)
1111 #define   PN(F) __PSN(#F, p->F)
1112 
1113 
1114 #ifdef CONFIG_NUMA_BALANCING
1115 void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1116 		unsigned long tpf, unsigned long gsf, unsigned long gpf)
1117 {
1118 	SEQ_printf(m, "numa_faults node=%d ", node);
1119 	SEQ_printf(m, "task_private=%lu task_shared=%lu ", tpf, tsf);
1120 	SEQ_printf(m, "group_private=%lu group_shared=%lu\n", gpf, gsf);
1121 }
1122 #endif
1123 
1124 
1125 static void sched_show_numa(struct task_struct *p, struct seq_file *m)
1126 {
1127 #ifdef CONFIG_NUMA_BALANCING
1128 	if (p->mm)
1129 		P(mm->numa_scan_seq);
1130 
1131 	P(numa_pages_migrated);
1132 	P(numa_preferred_nid);
1133 	P(total_numa_faults);
1134 	SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
1135 			task_node(p), task_numa_group_id(p));
1136 	show_numa_stats(p, m);
1137 #endif /* CONFIG_NUMA_BALANCING */
1138 }
1139 
1140 void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
1141 						  struct seq_file *m)
1142 {
1143 	unsigned long nr_switches;
1144 
1145 	SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns),
1146 						get_nr_threads(p));
1147 	SEQ_printf(m,
1148 		"---------------------------------------------------------"
1149 		"----------\n");
1150 
1151 #define P_SCHEDSTAT(F)  __PS(#F, schedstat_val(p->stats.F))
1152 #define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->stats.F))
1153 
1154 	PN(se.exec_start);
1155 	PN(se.vruntime);
1156 	PN(se.sum_exec_runtime);
1157 
1158 	nr_switches = p->nvcsw + p->nivcsw;
1159 
1160 	P(se.nr_migrations);
1161 
1162 	if (schedstat_enabled()) {
1163 		u64 avg_atom, avg_per_cpu;
1164 
1165 		PN_SCHEDSTAT(sum_sleep_runtime);
1166 		PN_SCHEDSTAT(sum_block_runtime);
1167 		PN_SCHEDSTAT(wait_start);
1168 		PN_SCHEDSTAT(sleep_start);
1169 		PN_SCHEDSTAT(block_start);
1170 		PN_SCHEDSTAT(sleep_max);
1171 		PN_SCHEDSTAT(block_max);
1172 		PN_SCHEDSTAT(exec_max);
1173 		PN_SCHEDSTAT(slice_max);
1174 		PN_SCHEDSTAT(wait_max);
1175 		PN_SCHEDSTAT(wait_sum);
1176 		P_SCHEDSTAT(wait_count);
1177 		PN_SCHEDSTAT(iowait_sum);
1178 		P_SCHEDSTAT(iowait_count);
1179 		P_SCHEDSTAT(nr_migrations_cold);
1180 		P_SCHEDSTAT(nr_failed_migrations_affine);
1181 		P_SCHEDSTAT(nr_failed_migrations_running);
1182 		P_SCHEDSTAT(nr_failed_migrations_hot);
1183 		P_SCHEDSTAT(nr_forced_migrations);
1184 		P_SCHEDSTAT(nr_wakeups);
1185 		P_SCHEDSTAT(nr_wakeups_sync);
1186 		P_SCHEDSTAT(nr_wakeups_migrate);
1187 		P_SCHEDSTAT(nr_wakeups_local);
1188 		P_SCHEDSTAT(nr_wakeups_remote);
1189 		P_SCHEDSTAT(nr_wakeups_affine);
1190 		P_SCHEDSTAT(nr_wakeups_affine_attempts);
1191 		P_SCHEDSTAT(nr_wakeups_passive);
1192 		P_SCHEDSTAT(nr_wakeups_idle);
1193 
1194 		avg_atom = p->se.sum_exec_runtime;
1195 		if (nr_switches)
1196 			avg_atom = div64_ul(avg_atom, nr_switches);
1197 		else
1198 			avg_atom = -1LL;
1199 
1200 		avg_per_cpu = p->se.sum_exec_runtime;
1201 		if (p->se.nr_migrations) {
1202 			avg_per_cpu = div64_u64(avg_per_cpu,
1203 						p->se.nr_migrations);
1204 		} else {
1205 			avg_per_cpu = -1LL;
1206 		}
1207 
1208 		__PN(avg_atom);
1209 		__PN(avg_per_cpu);
1210 
1211 #ifdef CONFIG_SCHED_CORE
1212 		PN_SCHEDSTAT(core_forceidle_sum);
1213 #endif
1214 	}
1215 
1216 	__P(nr_switches);
1217 	__PS("nr_voluntary_switches", p->nvcsw);
1218 	__PS("nr_involuntary_switches", p->nivcsw);
1219 
1220 	P(se.load.weight);
1221 	P(se.avg.load_sum);
1222 	P(se.avg.runnable_sum);
1223 	P(se.avg.util_sum);
1224 	P(se.avg.load_avg);
1225 	P(se.avg.runnable_avg);
1226 	P(se.avg.util_avg);
1227 	P(se.avg.last_update_time);
1228 	PM(se.avg.util_est, ~UTIL_AVG_UNCHANGED);
1229 #ifdef CONFIG_UCLAMP_TASK
1230 	__PS("uclamp.min", p->uclamp_req[UCLAMP_MIN].value);
1231 	__PS("uclamp.max", p->uclamp_req[UCLAMP_MAX].value);
1232 	__PS("effective uclamp.min", uclamp_eff_value(p, UCLAMP_MIN));
1233 	__PS("effective uclamp.max", uclamp_eff_value(p, UCLAMP_MAX));
1234 #endif /* CONFIG_UCLAMP_TASK */
1235 	P(policy);
1236 	P(prio);
1237 	if (task_has_dl_policy(p)) {
1238 		P(dl.runtime);
1239 		P(dl.deadline);
1240 	} else if (fair_policy(p->policy)) {
1241 		P(se.slice);
1242 	}
1243 #ifdef CONFIG_SCHED_CLASS_EXT
1244 	__PS("ext.enabled", task_on_scx(p));
1245 #endif
1246 #undef PN_SCHEDSTAT
1247 #undef P_SCHEDSTAT
1248 
1249 	{
1250 		unsigned int this_cpu = raw_smp_processor_id();
1251 		u64 t0, t1;
1252 
1253 		t0 = cpu_clock(this_cpu);
1254 		t1 = cpu_clock(this_cpu);
1255 		__PS("clock-delta", t1-t0);
1256 	}
1257 
1258 	sched_show_numa(p, m);
1259 }
1260 
1261 void proc_sched_set_task(struct task_struct *p)
1262 {
1263 #ifdef CONFIG_SCHEDSTATS
1264 	memset(&p->stats, 0, sizeof(p->stats));
1265 #endif
1266 }
1267 
1268 void resched_latency_warn(int cpu, u64 latency)
1269 {
1270 	static DEFINE_RATELIMIT_STATE(latency_check_ratelimit, 60 * 60 * HZ, 1);
1271 
1272 	if (likely(!__ratelimit(&latency_check_ratelimit)))
1273 		return;
1274 
1275 	pr_err("sched: CPU %d need_resched set for > %llu ns (%d ticks) without schedule\n",
1276 	       cpu, latency, cpu_rq(cpu)->ticks_without_resched);
1277 	dump_stack();
1278 }
1279