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 
10 /*
11  * This allows printing both to /sys/kernel/debug/sched/debug and
12  * to the console
13  */
14 #define SEQ_printf(m, x...)			\
15  do {						\
16 	if (m)					\
17 		seq_printf(m, x);		\
18 	else					\
19 		pr_cont(x);			\
20  } while (0)
21 
22 /*
23  * Ease the printing of nsec fields:
24  */
25 static long long nsec_high(unsigned long long nsec)
26 {
27 	if ((long long)nsec < 0) {
28 		nsec = -nsec;
29 		do_div(nsec, 1000000);
30 		return -nsec;
31 	}
32 	do_div(nsec, 1000000);
33 
34 	return nsec;
35 }
36 
37 static unsigned long nsec_low(unsigned long long nsec)
38 {
39 	if ((long long)nsec < 0)
40 		nsec = -nsec;
41 
42 	return do_div(nsec, 1000000);
43 }
44 
45 #define SPLIT_NS(x) nsec_high(x), nsec_low(x)
46 
47 #define SCHED_FEAT(name, enabled)	\
48 	#name ,
49 
50 static const char * const sched_feat_names[] = {
51 #include "features.h"
52 };
53 
54 #undef SCHED_FEAT
55 
56 static int sched_feat_show(struct seq_file *m, void *v)
57 {
58 	int i;
59 
60 	for (i = 0; i < __SCHED_FEAT_NR; i++) {
61 		if (!(sysctl_sched_features & (1UL << i)))
62 			seq_puts(m, "NO_");
63 		seq_printf(m, "%s ", sched_feat_names[i]);
64 	}
65 	seq_puts(m, "\n");
66 
67 	return 0;
68 }
69 
70 #ifdef CONFIG_JUMP_LABEL
71 
72 #define jump_label_key__true  STATIC_KEY_INIT_TRUE
73 #define jump_label_key__false STATIC_KEY_INIT_FALSE
74 
75 #define SCHED_FEAT(name, enabled)	\
76 	jump_label_key__##enabled ,
77 
78 struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
79 #include "features.h"
80 };
81 
82 #undef SCHED_FEAT
83 
84 static void sched_feat_disable(int i)
85 {
86 	static_key_disable_cpuslocked(&sched_feat_keys[i]);
87 }
88 
89 static void sched_feat_enable(int i)
90 {
91 	static_key_enable_cpuslocked(&sched_feat_keys[i]);
92 }
93 #else
94 static void sched_feat_disable(int i) { };
95 static void sched_feat_enable(int i) { };
96 #endif /* CONFIG_JUMP_LABEL */
97 
98 static int sched_feat_set(char *cmp)
99 {
100 	int i;
101 	int neg = 0;
102 
103 	if (strncmp(cmp, "NO_", 3) == 0) {
104 		neg = 1;
105 		cmp += 3;
106 	}
107 
108 	i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp);
109 	if (i < 0)
110 		return i;
111 
112 	if (neg) {
113 		sysctl_sched_features &= ~(1UL << i);
114 		sched_feat_disable(i);
115 	} else {
116 		sysctl_sched_features |= (1UL << i);
117 		sched_feat_enable(i);
118 	}
119 
120 	return 0;
121 }
122 
123 static ssize_t
124 sched_feat_write(struct file *filp, const char __user *ubuf,
125 		size_t cnt, loff_t *ppos)
126 {
127 	char buf[64];
128 	char *cmp;
129 	int ret;
130 	struct inode *inode;
131 
132 	if (cnt > 63)
133 		cnt = 63;
134 
135 	if (copy_from_user(&buf, ubuf, cnt))
136 		return -EFAULT;
137 
138 	buf[cnt] = 0;
139 	cmp = strstrip(buf);
140 
141 	/* Ensure the static_key remains in a consistent state */
142 	inode = file_inode(filp);
143 	cpus_read_lock();
144 	inode_lock(inode);
145 	ret = sched_feat_set(cmp);
146 	inode_unlock(inode);
147 	cpus_read_unlock();
148 	if (ret < 0)
149 		return ret;
150 
151 	*ppos += cnt;
152 
153 	return cnt;
154 }
155 
156 static int sched_feat_open(struct inode *inode, struct file *filp)
157 {
158 	return single_open(filp, sched_feat_show, NULL);
159 }
160 
161 static const struct file_operations sched_feat_fops = {
162 	.open		= sched_feat_open,
163 	.write		= sched_feat_write,
164 	.read		= seq_read,
165 	.llseek		= seq_lseek,
166 	.release	= single_release,
167 };
168 
169 #ifdef CONFIG_SMP
170 
171 static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf,
172 				   size_t cnt, loff_t *ppos)
173 {
174 	char buf[16];
175 	unsigned int scaling;
176 
177 	if (cnt > 15)
178 		cnt = 15;
179 
180 	if (copy_from_user(&buf, ubuf, cnt))
181 		return -EFAULT;
182 	buf[cnt] = '\0';
183 
184 	if (kstrtouint(buf, 10, &scaling))
185 		return -EINVAL;
186 
187 	if (scaling >= SCHED_TUNABLESCALING_END)
188 		return -EINVAL;
189 
190 	sysctl_sched_tunable_scaling = scaling;
191 	if (sched_update_scaling())
192 		return -EINVAL;
193 
194 	*ppos += cnt;
195 	return cnt;
196 }
197 
198 static int sched_scaling_show(struct seq_file *m, void *v)
199 {
200 	seq_printf(m, "%d\n", sysctl_sched_tunable_scaling);
201 	return 0;
202 }
203 
204 static int sched_scaling_open(struct inode *inode, struct file *filp)
205 {
206 	return single_open(filp, sched_scaling_show, NULL);
207 }
208 
209 static const struct file_operations sched_scaling_fops = {
210 	.open		= sched_scaling_open,
211 	.write		= sched_scaling_write,
212 	.read		= seq_read,
213 	.llseek		= seq_lseek,
214 	.release	= single_release,
215 };
216 
217 #endif /* SMP */
218 
219 #ifdef CONFIG_PREEMPT_DYNAMIC
220 
221 static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
222 				   size_t cnt, loff_t *ppos)
223 {
224 	char buf[16];
225 	int mode;
226 
227 	if (cnt > 15)
228 		cnt = 15;
229 
230 	if (copy_from_user(&buf, ubuf, cnt))
231 		return -EFAULT;
232 
233 	buf[cnt] = 0;
234 	mode = sched_dynamic_mode(strstrip(buf));
235 	if (mode < 0)
236 		return mode;
237 
238 	sched_dynamic_update(mode);
239 
240 	*ppos += cnt;
241 
242 	return cnt;
243 }
244 
245 static int sched_dynamic_show(struct seq_file *m, void *v)
246 {
247 	int i = IS_ENABLED(CONFIG_PREEMPT_RT) * 2;
248 	int j;
249 
250 	/* Count entries in NULL terminated preempt_modes */
251 	for (j = 0; preempt_modes[j]; j++)
252 		;
253 	j -= !IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY);
254 
255 	for (; i < j; i++) {
256 		if (preempt_dynamic_mode == i)
257 			seq_puts(m, "(");
258 		seq_puts(m, preempt_modes[i]);
259 		if (preempt_dynamic_mode == i)
260 			seq_puts(m, ")");
261 
262 		seq_puts(m, " ");
263 	}
264 
265 	seq_puts(m, "\n");
266 	return 0;
267 }
268 
269 static int sched_dynamic_open(struct inode *inode, struct file *filp)
270 {
271 	return single_open(filp, sched_dynamic_show, NULL);
272 }
273 
274 static const struct file_operations sched_dynamic_fops = {
275 	.open		= sched_dynamic_open,
276 	.write		= sched_dynamic_write,
277 	.read		= seq_read,
278 	.llseek		= seq_lseek,
279 	.release	= single_release,
280 };
281 
282 #endif /* CONFIG_PREEMPT_DYNAMIC */
283 
284 __read_mostly bool sched_debug_verbose;
285 
286 #ifdef CONFIG_SMP
287 static struct dentry           *sd_dentry;
288 
289 
290 static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
291 				  size_t cnt, loff_t *ppos)
292 {
293 	ssize_t result;
294 	bool orig;
295 
296 	cpus_read_lock();
297 	sched_domains_mutex_lock();
298 
299 	orig = sched_debug_verbose;
300 	result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
301 
302 	if (sched_debug_verbose && !orig)
303 		update_sched_domain_debugfs();
304 	else if (!sched_debug_verbose && orig) {
305 		debugfs_remove(sd_dentry);
306 		sd_dentry = NULL;
307 	}
308 
309 	sched_domains_mutex_unlock();
310 	cpus_read_unlock();
311 
312 	return result;
313 }
314 #else
315 #define sched_verbose_write debugfs_write_file_bool
316 #endif
317 
318 static const struct file_operations sched_verbose_fops = {
319 	.read =         debugfs_read_file_bool,
320 	.write =        sched_verbose_write,
321 	.open =         simple_open,
322 	.llseek =       default_llseek,
323 };
324 
325 static const struct seq_operations sched_debug_sops;
326 
327 static int sched_debug_open(struct inode *inode, struct file *filp)
328 {
329 	return seq_open(filp, &sched_debug_sops);
330 }
331 
332 static const struct file_operations sched_debug_fops = {
333 	.open		= sched_debug_open,
334 	.read		= seq_read,
335 	.llseek		= seq_lseek,
336 	.release	= seq_release,
337 };
338 
339 enum dl_param {
340 	DL_RUNTIME = 0,
341 	DL_PERIOD,
342 };
343 
344 static unsigned long fair_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */
345 static unsigned long fair_server_period_min = (100) * NSEC_PER_USEC;     /* 100 us */
346 
347 static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubuf,
348 				       size_t cnt, loff_t *ppos, enum dl_param param)
349 {
350 	long cpu = (long) ((struct seq_file *) filp->private_data)->private;
351 	struct rq *rq = cpu_rq(cpu);
352 	u64 runtime, period;
353 	size_t err;
354 	int retval;
355 	u64 value;
356 
357 	err = kstrtoull_from_user(ubuf, cnt, 10, &value);
358 	if (err)
359 		return err;
360 
361 	scoped_guard (rq_lock_irqsave, rq) {
362 		runtime  = rq->fair_server.dl_runtime;
363 		period = rq->fair_server.dl_period;
364 
365 		switch (param) {
366 		case DL_RUNTIME:
367 			if (runtime == value)
368 				break;
369 			runtime = value;
370 			break;
371 		case DL_PERIOD:
372 			if (value == period)
373 				break;
374 			period = value;
375 			break;
376 		}
377 
378 		if (runtime > period ||
379 		    period > fair_server_period_max ||
380 		    period < fair_server_period_min) {
381 			return  -EINVAL;
382 		}
383 
384 		if (rq->cfs.h_nr_queued) {
385 			update_rq_clock(rq);
386 			dl_server_stop(&rq->fair_server);
387 		}
388 
389 		retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
390 		if (retval)
391 			cnt = retval;
392 
393 		if (!runtime)
394 			printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n",
395 					cpu_of(rq));
396 
397 		if (rq->cfs.h_nr_queued)
398 			dl_server_start(&rq->fair_server);
399 	}
400 
401 	*ppos += cnt;
402 	return cnt;
403 }
404 
405 static size_t sched_fair_server_show(struct seq_file *m, void *v, enum dl_param param)
406 {
407 	unsigned long cpu = (unsigned long) m->private;
408 	struct rq *rq = cpu_rq(cpu);
409 	u64 value;
410 
411 	switch (param) {
412 	case DL_RUNTIME:
413 		value = rq->fair_server.dl_runtime;
414 		break;
415 	case DL_PERIOD:
416 		value = rq->fair_server.dl_period;
417 		break;
418 	}
419 
420 	seq_printf(m, "%llu\n", value);
421 	return 0;
422 
423 }
424 
425 static ssize_t
426 sched_fair_server_runtime_write(struct file *filp, const char __user *ubuf,
427 				size_t cnt, loff_t *ppos)
428 {
429 	return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_RUNTIME);
430 }
431 
432 static int sched_fair_server_runtime_show(struct seq_file *m, void *v)
433 {
434 	return sched_fair_server_show(m, v, DL_RUNTIME);
435 }
436 
437 static int sched_fair_server_runtime_open(struct inode *inode, struct file *filp)
438 {
439 	return single_open(filp, sched_fair_server_runtime_show, inode->i_private);
440 }
441 
442 static const struct file_operations fair_server_runtime_fops = {
443 	.open		= sched_fair_server_runtime_open,
444 	.write		= sched_fair_server_runtime_write,
445 	.read		= seq_read,
446 	.llseek		= seq_lseek,
447 	.release	= single_release,
448 };
449 
450 static ssize_t
451 sched_fair_server_period_write(struct file *filp, const char __user *ubuf,
452 			       size_t cnt, loff_t *ppos)
453 {
454 	return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_PERIOD);
455 }
456 
457 static int sched_fair_server_period_show(struct seq_file *m, void *v)
458 {
459 	return sched_fair_server_show(m, v, DL_PERIOD);
460 }
461 
462 static int sched_fair_server_period_open(struct inode *inode, struct file *filp)
463 {
464 	return single_open(filp, sched_fair_server_period_show, inode->i_private);
465 }
466 
467 static const struct file_operations fair_server_period_fops = {
468 	.open		= sched_fair_server_period_open,
469 	.write		= sched_fair_server_period_write,
470 	.read		= seq_read,
471 	.llseek		= seq_lseek,
472 	.release	= single_release,
473 };
474 
475 static struct dentry *debugfs_sched;
476 
477 static void debugfs_fair_server_init(void)
478 {
479 	struct dentry *d_fair;
480 	unsigned long cpu;
481 
482 	d_fair = debugfs_create_dir("fair_server", debugfs_sched);
483 	if (!d_fair)
484 		return;
485 
486 	for_each_possible_cpu(cpu) {
487 		struct dentry *d_cpu;
488 		char buf[32];
489 
490 		snprintf(buf, sizeof(buf), "cpu%lu", cpu);
491 		d_cpu = debugfs_create_dir(buf, d_fair);
492 
493 		debugfs_create_file("runtime", 0644, d_cpu, (void *) cpu, &fair_server_runtime_fops);
494 		debugfs_create_file("period", 0644, d_cpu, (void *) cpu, &fair_server_period_fops);
495 	}
496 }
497 
498 static __init int sched_init_debug(void)
499 {
500 	struct dentry __maybe_unused *numa;
501 
502 	debugfs_sched = debugfs_create_dir("sched", NULL);
503 
504 	debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
505 	debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops);
506 #ifdef CONFIG_PREEMPT_DYNAMIC
507 	debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
508 #endif
509 
510 	debugfs_create_u32("base_slice_ns", 0644, debugfs_sched, &sysctl_sched_base_slice);
511 
512 	debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms);
513 	debugfs_create_u32("latency_warn_once", 0644, debugfs_sched, &sysctl_resched_latency_warn_once);
514 
515 #ifdef CONFIG_SMP
516 	debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops);
517 	debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);
518 	debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);
519 
520 	sched_domains_mutex_lock();
521 	update_sched_domain_debugfs();
522 	sched_domains_mutex_unlock();
523 #endif
524 
525 #ifdef CONFIG_NUMA_BALANCING
526 	numa = debugfs_create_dir("numa_balancing", debugfs_sched);
527 
528 	debugfs_create_u32("scan_delay_ms", 0644, numa, &sysctl_numa_balancing_scan_delay);
529 	debugfs_create_u32("scan_period_min_ms", 0644, numa, &sysctl_numa_balancing_scan_period_min);
530 	debugfs_create_u32("scan_period_max_ms", 0644, numa, &sysctl_numa_balancing_scan_period_max);
531 	debugfs_create_u32("scan_size_mb", 0644, numa, &sysctl_numa_balancing_scan_size);
532 	debugfs_create_u32("hot_threshold_ms", 0644, numa, &sysctl_numa_balancing_hot_threshold);
533 #endif
534 
535 	debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops);
536 
537 	debugfs_fair_server_init();
538 
539 	return 0;
540 }
541 late_initcall(sched_init_debug);
542 
543 #ifdef CONFIG_SMP
544 
545 static cpumask_var_t		sd_sysctl_cpus;
546 
547 static int sd_flags_show(struct seq_file *m, void *v)
548 {
549 	unsigned long flags = *(unsigned int *)m->private;
550 	int idx;
551 
552 	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
553 		seq_puts(m, sd_flag_debug[idx].name);
554 		seq_puts(m, " ");
555 	}
556 	seq_puts(m, "\n");
557 
558 	return 0;
559 }
560 
561 static int sd_flags_open(struct inode *inode, struct file *file)
562 {
563 	return single_open(file, sd_flags_show, inode->i_private);
564 }
565 
566 static const struct file_operations sd_flags_fops = {
567 	.open		= sd_flags_open,
568 	.read		= seq_read,
569 	.llseek		= seq_lseek,
570 	.release	= single_release,
571 };
572 
573 static void register_sd(struct sched_domain *sd, struct dentry *parent)
574 {
575 #define SDM(type, mode, member)	\
576 	debugfs_create_##type(#member, mode, parent, &sd->member)
577 
578 	SDM(ulong, 0644, min_interval);
579 	SDM(ulong, 0644, max_interval);
580 	SDM(u64,   0644, max_newidle_lb_cost);
581 	SDM(u32,   0644, busy_factor);
582 	SDM(u32,   0644, imbalance_pct);
583 	SDM(u32,   0644, cache_nice_tries);
584 	SDM(str,   0444, name);
585 
586 #undef SDM
587 
588 	debugfs_create_file("flags", 0444, parent, &sd->flags, &sd_flags_fops);
589 	debugfs_create_file("groups_flags", 0444, parent, &sd->groups->flags, &sd_flags_fops);
590 	debugfs_create_u32("level", 0444, parent, (u32 *)&sd->level);
591 
592 	if (sd->flags & SD_ASYM_PACKING)
593 		debugfs_create_u32("group_asym_prefer_cpu", 0444, parent,
594 				   (u32 *)&sd->groups->asym_prefer_cpu);
595 }
596 
597 void update_sched_domain_debugfs(void)
598 {
599 	int cpu, i;
600 
601 	/*
602 	 * This can unfortunately be invoked before sched_debug_init() creates
603 	 * the debug directory. Don't touch sd_sysctl_cpus until then.
604 	 */
605 	if (!debugfs_sched)
606 		return;
607 
608 	if (!sched_debug_verbose)
609 		return;
610 
611 	if (!cpumask_available(sd_sysctl_cpus)) {
612 		if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
613 			return;
614 		cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
615 	}
616 
617 	if (!sd_dentry) {
618 		sd_dentry = debugfs_create_dir("domains", debugfs_sched);
619 
620 		/* rebuild sd_sysctl_cpus if empty since it gets cleared below */
621 		if (cpumask_empty(sd_sysctl_cpus))
622 			cpumask_copy(sd_sysctl_cpus, cpu_online_mask);
623 	}
624 
625 	for_each_cpu(cpu, sd_sysctl_cpus) {
626 		struct sched_domain *sd;
627 		struct dentry *d_cpu;
628 		char buf[32];
629 
630 		snprintf(buf, sizeof(buf), "cpu%d", cpu);
631 		debugfs_lookup_and_remove(buf, sd_dentry);
632 		d_cpu = debugfs_create_dir(buf, sd_dentry);
633 
634 		i = 0;
635 		for_each_domain(cpu, sd) {
636 			struct dentry *d_sd;
637 
638 			snprintf(buf, sizeof(buf), "domain%d", i);
639 			d_sd = debugfs_create_dir(buf, d_cpu);
640 
641 			register_sd(sd, d_sd);
642 			i++;
643 		}
644 
645 		__cpumask_clear_cpu(cpu, sd_sysctl_cpus);
646 	}
647 }
648 
649 void dirty_sched_domain_sysctl(int cpu)
650 {
651 	if (cpumask_available(sd_sysctl_cpus))
652 		__cpumask_set_cpu(cpu, sd_sysctl_cpus);
653 }
654 
655 #endif /* CONFIG_SMP */
656 
657 #ifdef CONFIG_FAIR_GROUP_SCHED
658 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
659 {
660 	struct sched_entity *se = tg->se[cpu];
661 
662 #define P(F)		SEQ_printf(m, "  .%-30s: %lld\n",	#F, (long long)F)
663 #define P_SCHEDSTAT(F)	SEQ_printf(m, "  .%-30s: %lld\n",	\
664 		#F, (long long)schedstat_val(stats->F))
665 #define PN(F)		SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
666 #define PN_SCHEDSTAT(F)	SEQ_printf(m, "  .%-30s: %lld.%06ld\n", \
667 		#F, SPLIT_NS((long long)schedstat_val(stats->F)))
668 
669 	if (!se)
670 		return;
671 
672 	PN(se->exec_start);
673 	PN(se->vruntime);
674 	PN(se->sum_exec_runtime);
675 
676 	if (schedstat_enabled()) {
677 		struct sched_statistics *stats;
678 		stats = __schedstats_from_se(se);
679 
680 		PN_SCHEDSTAT(wait_start);
681 		PN_SCHEDSTAT(sleep_start);
682 		PN_SCHEDSTAT(block_start);
683 		PN_SCHEDSTAT(sleep_max);
684 		PN_SCHEDSTAT(block_max);
685 		PN_SCHEDSTAT(exec_max);
686 		PN_SCHEDSTAT(slice_max);
687 		PN_SCHEDSTAT(wait_max);
688 		PN_SCHEDSTAT(wait_sum);
689 		P_SCHEDSTAT(wait_count);
690 	}
691 
692 	P(se->load.weight);
693 #ifdef CONFIG_SMP
694 	P(se->avg.load_avg);
695 	P(se->avg.util_avg);
696 	P(se->avg.runnable_avg);
697 #endif
698 
699 #undef PN_SCHEDSTAT
700 #undef PN
701 #undef P_SCHEDSTAT
702 #undef P
703 }
704 #endif
705 
706 #ifdef CONFIG_CGROUP_SCHED
707 static DEFINE_SPINLOCK(sched_debug_lock);
708 static char group_path[PATH_MAX];
709 
710 static void task_group_path(struct task_group *tg, char *path, int plen)
711 {
712 	if (autogroup_path(tg, path, plen))
713 		return;
714 
715 	cgroup_path(tg->css.cgroup, path, plen);
716 }
717 
718 /*
719  * Only 1 SEQ_printf_task_group_path() caller can use the full length
720  * group_path[] for cgroup path. Other simultaneous callers will have
721  * to use a shorter stack buffer. A "..." suffix is appended at the end
722  * of the stack buffer so that it will show up in case the output length
723  * matches the given buffer size to indicate possible path name truncation.
724  */
725 #define SEQ_printf_task_group_path(m, tg, fmt...)			\
726 {									\
727 	if (spin_trylock(&sched_debug_lock)) {				\
728 		task_group_path(tg, group_path, sizeof(group_path));	\
729 		SEQ_printf(m, fmt, group_path);				\
730 		spin_unlock(&sched_debug_lock);				\
731 	} else {							\
732 		char buf[128];						\
733 		char *bufend = buf + sizeof(buf) - 3;			\
734 		task_group_path(tg, buf, bufend - buf);			\
735 		strcpy(bufend - 1, "...");				\
736 		SEQ_printf(m, fmt, buf);				\
737 	}								\
738 }
739 #endif
740 
741 static void
742 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
743 {
744 	if (task_current(rq, p))
745 		SEQ_printf(m, ">R");
746 	else
747 		SEQ_printf(m, " %c", task_state_to_char(p));
748 
749 	SEQ_printf(m, " %15s %5d %9Ld.%06ld   %c   %9Ld.%06ld %c %9Ld.%06ld %9Ld.%06ld %9Ld   %5d ",
750 		p->comm, task_pid_nr(p),
751 		SPLIT_NS(p->se.vruntime),
752 		entity_eligible(cfs_rq_of(&p->se), &p->se) ? 'E' : 'N',
753 		SPLIT_NS(p->se.deadline),
754 		p->se.custom_slice ? 'S' : ' ',
755 		SPLIT_NS(p->se.slice),
756 		SPLIT_NS(p->se.sum_exec_runtime),
757 		(long long)(p->nvcsw + p->nivcsw),
758 		p->prio);
759 
760 	SEQ_printf(m, "%9lld.%06ld %9lld.%06ld %9lld.%06ld",
761 		SPLIT_NS(schedstat_val_or_zero(p->stats.wait_sum)),
762 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)),
763 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime)));
764 
765 #ifdef CONFIG_NUMA_BALANCING
766 	SEQ_printf(m, "   %d      %d", task_node(p), task_numa_group_id(p));
767 #endif
768 #ifdef CONFIG_CGROUP_SCHED
769 	SEQ_printf_task_group_path(m, task_group(p), "        %s")
770 #endif
771 
772 	SEQ_printf(m, "\n");
773 }
774 
775 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
776 {
777 	struct task_struct *g, *p;
778 
779 	SEQ_printf(m, "\n");
780 	SEQ_printf(m, "runnable tasks:\n");
781 	SEQ_printf(m, " S            task   PID       vruntime   eligible    "
782 		   "deadline             slice          sum-exec      switches  "
783 		   "prio         wait-time        sum-sleep       sum-block"
784 #ifdef CONFIG_NUMA_BALANCING
785 		   "  node   group-id"
786 #endif
787 #ifdef CONFIG_CGROUP_SCHED
788 		   "  group-path"
789 #endif
790 		   "\n");
791 	SEQ_printf(m, "-------------------------------------------------------"
792 		   "------------------------------------------------------"
793 		   "------------------------------------------------------"
794 #ifdef CONFIG_NUMA_BALANCING
795 		   "--------------"
796 #endif
797 #ifdef CONFIG_CGROUP_SCHED
798 		   "--------------"
799 #endif
800 		   "\n");
801 
802 	rcu_read_lock();
803 	for_each_process_thread(g, p) {
804 		if (task_cpu(p) != rq_cpu)
805 			continue;
806 
807 		print_task(m, rq, p);
808 	}
809 	rcu_read_unlock();
810 }
811 
812 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
813 {
814 	s64 left_vruntime = -1, min_vruntime, right_vruntime = -1, left_deadline = -1, spread;
815 	struct sched_entity *last, *first, *root;
816 	struct rq *rq = cpu_rq(cpu);
817 	unsigned long flags;
818 
819 #ifdef CONFIG_FAIR_GROUP_SCHED
820 	SEQ_printf(m, "\n");
821 	SEQ_printf_task_group_path(m, cfs_rq->tg, "cfs_rq[%d]:%s\n", cpu);
822 #else
823 	SEQ_printf(m, "\n");
824 	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
825 #endif
826 
827 	raw_spin_rq_lock_irqsave(rq, flags);
828 	root = __pick_root_entity(cfs_rq);
829 	if (root)
830 		left_vruntime = root->min_vruntime;
831 	first = __pick_first_entity(cfs_rq);
832 	if (first)
833 		left_deadline = first->deadline;
834 	last = __pick_last_entity(cfs_rq);
835 	if (last)
836 		right_vruntime = last->vruntime;
837 	min_vruntime = cfs_rq->min_vruntime;
838 	raw_spin_rq_unlock_irqrestore(rq, flags);
839 
840 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "left_deadline",
841 			SPLIT_NS(left_deadline));
842 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "left_vruntime",
843 			SPLIT_NS(left_vruntime));
844 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
845 			SPLIT_NS(min_vruntime));
846 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "avg_vruntime",
847 			SPLIT_NS(avg_vruntime(cfs_rq)));
848 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "right_vruntime",
849 			SPLIT_NS(right_vruntime));
850 	spread = right_vruntime - left_vruntime;
851 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
852 	SEQ_printf(m, "  .%-30s: %d\n", "nr_queued", cfs_rq->nr_queued);
853 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_runnable", cfs_rq->h_nr_runnable);
854 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_queued", cfs_rq->h_nr_queued);
855 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_idle", cfs_rq->h_nr_idle);
856 	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
857 #ifdef CONFIG_SMP
858 	SEQ_printf(m, "  .%-30s: %lu\n", "load_avg",
859 			cfs_rq->avg.load_avg);
860 	SEQ_printf(m, "  .%-30s: %lu\n", "runnable_avg",
861 			cfs_rq->avg.runnable_avg);
862 	SEQ_printf(m, "  .%-30s: %lu\n", "util_avg",
863 			cfs_rq->avg.util_avg);
864 	SEQ_printf(m, "  .%-30s: %u\n", "util_est",
865 			cfs_rq->avg.util_est);
866 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.load_avg",
867 			cfs_rq->removed.load_avg);
868 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.util_avg",
869 			cfs_rq->removed.util_avg);
870 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.runnable_avg",
871 			cfs_rq->removed.runnable_avg);
872 #ifdef CONFIG_FAIR_GROUP_SCHED
873 	SEQ_printf(m, "  .%-30s: %lu\n", "tg_load_avg_contrib",
874 			cfs_rq->tg_load_avg_contrib);
875 	SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_avg",
876 			atomic_long_read(&cfs_rq->tg->load_avg));
877 #endif
878 #endif
879 #ifdef CONFIG_CFS_BANDWIDTH
880 	SEQ_printf(m, "  .%-30s: %d\n", "throttled",
881 			cfs_rq->throttled);
882 	SEQ_printf(m, "  .%-30s: %d\n", "throttle_count",
883 			cfs_rq->throttle_count);
884 #endif
885 
886 #ifdef CONFIG_FAIR_GROUP_SCHED
887 	print_cfs_group_stats(m, cpu, cfs_rq->tg);
888 #endif
889 }
890 
891 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
892 {
893 #ifdef CONFIG_RT_GROUP_SCHED
894 	SEQ_printf(m, "\n");
895 	SEQ_printf_task_group_path(m, rt_rq->tg, "rt_rq[%d]:%s\n", cpu);
896 #else
897 	SEQ_printf(m, "\n");
898 	SEQ_printf(m, "rt_rq[%d]:\n", cpu);
899 #endif
900 
901 #define P(x) \
902 	SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
903 #define PU(x) \
904 	SEQ_printf(m, "  .%-30s: %lu\n", #x, (unsigned long)(rt_rq->x))
905 #define PN(x) \
906 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
907 
908 	PU(rt_nr_running);
909 
910 #ifdef CONFIG_RT_GROUP_SCHED
911 	P(rt_throttled);
912 	PN(rt_time);
913 	PN(rt_runtime);
914 #endif
915 
916 #undef PN
917 #undef PU
918 #undef P
919 }
920 
921 void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
922 {
923 	struct dl_bw *dl_bw;
924 
925 	SEQ_printf(m, "\n");
926 	SEQ_printf(m, "dl_rq[%d]:\n", cpu);
927 
928 #define PU(x) \
929 	SEQ_printf(m, "  .%-30s: %lu\n", #x, (unsigned long)(dl_rq->x))
930 
931 	PU(dl_nr_running);
932 #ifdef CONFIG_SMP
933 	dl_bw = &cpu_rq(cpu)->rd->dl_bw;
934 #else
935 	dl_bw = &dl_rq->dl_bw;
936 #endif
937 	SEQ_printf(m, "  .%-30s: %lld\n", "dl_bw->bw", dl_bw->bw);
938 	SEQ_printf(m, "  .%-30s: %lld\n", "dl_bw->total_bw", dl_bw->total_bw);
939 
940 #undef PU
941 }
942 
943 static void print_cpu(struct seq_file *m, int cpu)
944 {
945 	struct rq *rq = cpu_rq(cpu);
946 
947 #ifdef CONFIG_X86
948 	{
949 		unsigned int freq = cpu_khz ? : 1;
950 
951 		SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
952 			   cpu, freq / 1000, (freq % 1000));
953 	}
954 #else
955 	SEQ_printf(m, "cpu#%d\n", cpu);
956 #endif
957 
958 #define P(x)								\
959 do {									\
960 	if (sizeof(rq->x) == 4)						\
961 		SEQ_printf(m, "  .%-30s: %d\n", #x, (int)(rq->x));	\
962 	else								\
963 		SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x));\
964 } while (0)
965 
966 #define PN(x) \
967 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
968 
969 	P(nr_running);
970 	P(nr_switches);
971 	P(nr_uninterruptible);
972 	PN(next_balance);
973 	SEQ_printf(m, "  .%-30s: %ld\n", "curr->pid", (long)(task_pid_nr(rq->curr)));
974 	PN(clock);
975 	PN(clock_task);
976 #undef P
977 #undef PN
978 
979 #ifdef CONFIG_SMP
980 #define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);
981 	P64(avg_idle);
982 	P64(max_idle_balance_cost);
983 #undef P64
984 #endif
985 
986 #define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, schedstat_val(rq->n));
987 	if (schedstat_enabled()) {
988 		P(yld_count);
989 		P(sched_count);
990 		P(sched_goidle);
991 		P(ttwu_count);
992 		P(ttwu_local);
993 	}
994 #undef P
995 
996 	print_cfs_stats(m, cpu);
997 	print_rt_stats(m, cpu);
998 	print_dl_stats(m, cpu);
999 
1000 	print_rq(m, rq, cpu);
1001 	SEQ_printf(m, "\n");
1002 }
1003 
1004 static const char *sched_tunable_scaling_names[] = {
1005 	"none",
1006 	"logarithmic",
1007 	"linear"
1008 };
1009 
1010 static void sched_debug_header(struct seq_file *m)
1011 {
1012 	u64 ktime, sched_clk, cpu_clk;
1013 	unsigned long flags;
1014 
1015 	local_irq_save(flags);
1016 	ktime = ktime_to_ns(ktime_get());
1017 	sched_clk = sched_clock();
1018 	cpu_clk = local_clock();
1019 	local_irq_restore(flags);
1020 
1021 	SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n",
1022 		init_utsname()->release,
1023 		(int)strcspn(init_utsname()->version, " "),
1024 		init_utsname()->version);
1025 
1026 #define P(x) \
1027 	SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
1028 #define PN(x) \
1029 	SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
1030 	PN(ktime);
1031 	PN(sched_clk);
1032 	PN(cpu_clk);
1033 	P(jiffies);
1034 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1035 	P(sched_clock_stable());
1036 #endif
1037 #undef PN
1038 #undef P
1039 
1040 	SEQ_printf(m, "\n");
1041 	SEQ_printf(m, "sysctl_sched\n");
1042 
1043 #define P(x) \
1044 	SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
1045 #define PN(x) \
1046 	SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
1047 	PN(sysctl_sched_base_slice);
1048 	P(sysctl_sched_features);
1049 #undef PN
1050 #undef P
1051 
1052 	SEQ_printf(m, "  .%-40s: %d (%s)\n",
1053 		"sysctl_sched_tunable_scaling",
1054 		sysctl_sched_tunable_scaling,
1055 		sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
1056 	SEQ_printf(m, "\n");
1057 }
1058 
1059 static int sched_debug_show(struct seq_file *m, void *v)
1060 {
1061 	int cpu = (unsigned long)(v - 2);
1062 
1063 	if (cpu != -1)
1064 		print_cpu(m, cpu);
1065 	else
1066 		sched_debug_header(m);
1067 
1068 	return 0;
1069 }
1070 
1071 void sysrq_sched_debug_show(void)
1072 {
1073 	int cpu;
1074 
1075 	sched_debug_header(NULL);
1076 	for_each_online_cpu(cpu) {
1077 		/*
1078 		 * Need to reset softlockup watchdogs on all CPUs, because
1079 		 * another CPU might be blocked waiting for us to process
1080 		 * an IPI or stop_machine.
1081 		 */
1082 		touch_nmi_watchdog();
1083 		touch_all_softlockup_watchdogs();
1084 		print_cpu(NULL, cpu);
1085 	}
1086 }
1087 
1088 /*
1089  * This iterator needs some explanation.
1090  * It returns 1 for the header position.
1091  * This means 2 is CPU 0.
1092  * In a hotplugged system some CPUs, including CPU 0, may be missing so we have
1093  * to use cpumask_* to iterate over the CPUs.
1094  */
1095 static void *sched_debug_start(struct seq_file *file, loff_t *offset)
1096 {
1097 	unsigned long n = *offset;
1098 
1099 	if (n == 0)
1100 		return (void *) 1;
1101 
1102 	n--;
1103 
1104 	if (n > 0)
1105 		n = cpumask_next(n - 1, cpu_online_mask);
1106 	else
1107 		n = cpumask_first(cpu_online_mask);
1108 
1109 	*offset = n + 1;
1110 
1111 	if (n < nr_cpu_ids)
1112 		return (void *)(unsigned long)(n + 2);
1113 
1114 	return NULL;
1115 }
1116 
1117 static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
1118 {
1119 	(*offset)++;
1120 	return sched_debug_start(file, offset);
1121 }
1122 
1123 static void sched_debug_stop(struct seq_file *file, void *data)
1124 {
1125 }
1126 
1127 static const struct seq_operations sched_debug_sops = {
1128 	.start		= sched_debug_start,
1129 	.next		= sched_debug_next,
1130 	.stop		= sched_debug_stop,
1131 	.show		= sched_debug_show,
1132 };
1133 
1134 #define __PS(S, F) SEQ_printf(m, "%-45s:%21Ld\n", S, (long long)(F))
1135 #define __P(F) __PS(#F, F)
1136 #define   P(F) __PS(#F, p->F)
1137 #define   PM(F, M) __PS(#F, p->F & (M))
1138 #define __PSN(S, F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", S, SPLIT_NS((long long)(F)))
1139 #define __PN(F) __PSN(#F, F)
1140 #define   PN(F) __PSN(#F, p->F)
1141 
1142 
1143 #ifdef CONFIG_NUMA_BALANCING
1144 void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1145 		unsigned long tpf, unsigned long gsf, unsigned long gpf)
1146 {
1147 	SEQ_printf(m, "numa_faults node=%d ", node);
1148 	SEQ_printf(m, "task_private=%lu task_shared=%lu ", tpf, tsf);
1149 	SEQ_printf(m, "group_private=%lu group_shared=%lu\n", gpf, gsf);
1150 }
1151 #endif
1152 
1153 
1154 static void sched_show_numa(struct task_struct *p, struct seq_file *m)
1155 {
1156 #ifdef CONFIG_NUMA_BALANCING
1157 	if (p->mm)
1158 		P(mm->numa_scan_seq);
1159 
1160 	P(numa_pages_migrated);
1161 	P(numa_preferred_nid);
1162 	P(total_numa_faults);
1163 	SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
1164 			task_node(p), task_numa_group_id(p));
1165 	show_numa_stats(p, m);
1166 #endif
1167 }
1168 
1169 void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
1170 						  struct seq_file *m)
1171 {
1172 	unsigned long nr_switches;
1173 
1174 	SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns),
1175 						get_nr_threads(p));
1176 	SEQ_printf(m,
1177 		"---------------------------------------------------------"
1178 		"----------\n");
1179 
1180 #define P_SCHEDSTAT(F)  __PS(#F, schedstat_val(p->stats.F))
1181 #define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->stats.F))
1182 
1183 	PN(se.exec_start);
1184 	PN(se.vruntime);
1185 	PN(se.sum_exec_runtime);
1186 
1187 	nr_switches = p->nvcsw + p->nivcsw;
1188 
1189 	P(se.nr_migrations);
1190 
1191 	if (schedstat_enabled()) {
1192 		u64 avg_atom, avg_per_cpu;
1193 
1194 		PN_SCHEDSTAT(sum_sleep_runtime);
1195 		PN_SCHEDSTAT(sum_block_runtime);
1196 		PN_SCHEDSTAT(wait_start);
1197 		PN_SCHEDSTAT(sleep_start);
1198 		PN_SCHEDSTAT(block_start);
1199 		PN_SCHEDSTAT(sleep_max);
1200 		PN_SCHEDSTAT(block_max);
1201 		PN_SCHEDSTAT(exec_max);
1202 		PN_SCHEDSTAT(slice_max);
1203 		PN_SCHEDSTAT(wait_max);
1204 		PN_SCHEDSTAT(wait_sum);
1205 		P_SCHEDSTAT(wait_count);
1206 		PN_SCHEDSTAT(iowait_sum);
1207 		P_SCHEDSTAT(iowait_count);
1208 		P_SCHEDSTAT(nr_migrations_cold);
1209 		P_SCHEDSTAT(nr_failed_migrations_affine);
1210 		P_SCHEDSTAT(nr_failed_migrations_running);
1211 		P_SCHEDSTAT(nr_failed_migrations_hot);
1212 		P_SCHEDSTAT(nr_forced_migrations);
1213 #ifdef CONFIG_NUMA_BALANCING
1214 		P_SCHEDSTAT(numa_task_migrated);
1215 		P_SCHEDSTAT(numa_task_swapped);
1216 #endif
1217 		P_SCHEDSTAT(nr_wakeups);
1218 		P_SCHEDSTAT(nr_wakeups_sync);
1219 		P_SCHEDSTAT(nr_wakeups_migrate);
1220 		P_SCHEDSTAT(nr_wakeups_local);
1221 		P_SCHEDSTAT(nr_wakeups_remote);
1222 		P_SCHEDSTAT(nr_wakeups_affine);
1223 		P_SCHEDSTAT(nr_wakeups_affine_attempts);
1224 		P_SCHEDSTAT(nr_wakeups_passive);
1225 		P_SCHEDSTAT(nr_wakeups_idle);
1226 
1227 		avg_atom = p->se.sum_exec_runtime;
1228 		if (nr_switches)
1229 			avg_atom = div64_ul(avg_atom, nr_switches);
1230 		else
1231 			avg_atom = -1LL;
1232 
1233 		avg_per_cpu = p->se.sum_exec_runtime;
1234 		if (p->se.nr_migrations) {
1235 			avg_per_cpu = div64_u64(avg_per_cpu,
1236 						p->se.nr_migrations);
1237 		} else {
1238 			avg_per_cpu = -1LL;
1239 		}
1240 
1241 		__PN(avg_atom);
1242 		__PN(avg_per_cpu);
1243 
1244 #ifdef CONFIG_SCHED_CORE
1245 		PN_SCHEDSTAT(core_forceidle_sum);
1246 #endif
1247 	}
1248 
1249 	__P(nr_switches);
1250 	__PS("nr_voluntary_switches", p->nvcsw);
1251 	__PS("nr_involuntary_switches", p->nivcsw);
1252 
1253 	P(se.load.weight);
1254 #ifdef CONFIG_SMP
1255 	P(se.avg.load_sum);
1256 	P(se.avg.runnable_sum);
1257 	P(se.avg.util_sum);
1258 	P(se.avg.load_avg);
1259 	P(se.avg.runnable_avg);
1260 	P(se.avg.util_avg);
1261 	P(se.avg.last_update_time);
1262 	PM(se.avg.util_est, ~UTIL_AVG_UNCHANGED);
1263 #endif
1264 #ifdef CONFIG_UCLAMP_TASK
1265 	__PS("uclamp.min", p->uclamp_req[UCLAMP_MIN].value);
1266 	__PS("uclamp.max", p->uclamp_req[UCLAMP_MAX].value);
1267 	__PS("effective uclamp.min", uclamp_eff_value(p, UCLAMP_MIN));
1268 	__PS("effective uclamp.max", uclamp_eff_value(p, UCLAMP_MAX));
1269 #endif
1270 	P(policy);
1271 	P(prio);
1272 	if (task_has_dl_policy(p)) {
1273 		P(dl.runtime);
1274 		P(dl.deadline);
1275 	} else if (fair_policy(p->policy)) {
1276 		P(se.slice);
1277 	}
1278 #ifdef CONFIG_SCHED_CLASS_EXT
1279 	__PS("ext.enabled", task_on_scx(p));
1280 #endif
1281 #undef PN_SCHEDSTAT
1282 #undef P_SCHEDSTAT
1283 
1284 	{
1285 		unsigned int this_cpu = raw_smp_processor_id();
1286 		u64 t0, t1;
1287 
1288 		t0 = cpu_clock(this_cpu);
1289 		t1 = cpu_clock(this_cpu);
1290 		__PS("clock-delta", t1-t0);
1291 	}
1292 
1293 	sched_show_numa(p, m);
1294 }
1295 
1296 void proc_sched_set_task(struct task_struct *p)
1297 {
1298 #ifdef CONFIG_SCHEDSTATS
1299 	memset(&p->stats, 0, sizeof(p->stats));
1300 #endif
1301 }
1302 
1303 void resched_latency_warn(int cpu, u64 latency)
1304 {
1305 	static DEFINE_RATELIMIT_STATE(latency_check_ratelimit, 60 * 60 * HZ, 1);
1306 
1307 	if (likely(!__ratelimit(&latency_check_ratelimit)))
1308 		return;
1309 
1310 	pr_err("sched: CPU %d need_resched set for > %llu ns (%d ticks) without schedule\n",
1311 	       cpu, latency, cpu_rq(cpu)->ticks_without_resched);
1312 	dump_stack();
1313 }
1314