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1 /*
2  * kernel/time/sched_debug.c
3  *
4  * Print the CFS rbtree
5  *
6  * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/proc_fs.h>
14 #include <linux/sched.h>
15 #include <linux/seq_file.h>
16 #include <linux/kallsyms.h>
17 #include <linux/utsname.h>
18 
19 /*
20  * This allows printing both to /proc/sched_debug and
21  * to the console
22  */
23 #define SEQ_printf(m, x...)			\
24  do {						\
25 	if (m)					\
26 		seq_printf(m, x);		\
27 	else					\
28 		printk(x);			\
29  } while (0)
30 
31 /*
32  * Ease the printing of nsec fields:
33  */
nsec_high(unsigned long long nsec)34 static long long nsec_high(unsigned long long nsec)
35 {
36 	if ((long long)nsec < 0) {
37 		nsec = -nsec;
38 		do_div(nsec, 1000000);
39 		return -nsec;
40 	}
41 	do_div(nsec, 1000000);
42 
43 	return nsec;
44 }
45 
nsec_low(unsigned long long nsec)46 static unsigned long nsec_low(unsigned long long nsec)
47 {
48 	if ((long long)nsec < 0)
49 		nsec = -nsec;
50 
51 	return do_div(nsec, 1000000);
52 }
53 
54 #define SPLIT_NS(x) nsec_high(x), nsec_low(x)
55 
56 #ifdef CONFIG_FAIR_GROUP_SCHED
print_cfs_group_stats(struct seq_file * m,int cpu,struct task_group * tg)57 static void print_cfs_group_stats(struct seq_file *m, int cpu,
58 		struct task_group *tg)
59 {
60 	struct sched_entity *se = tg->se[cpu];
61 	if (!se)
62 		return;
63 
64 #define P(F) \
65 	SEQ_printf(m, "  .%-30s: %lld\n", #F, (long long)F)
66 #define PN(F) \
67 	SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
68 
69 	PN(se->exec_start);
70 	PN(se->vruntime);
71 	PN(se->sum_exec_runtime);
72 #ifdef CONFIG_SCHEDSTATS
73 	PN(se->wait_start);
74 	PN(se->sleep_start);
75 	PN(se->block_start);
76 	PN(se->sleep_max);
77 	PN(se->block_max);
78 	PN(se->exec_max);
79 	PN(se->slice_max);
80 	PN(se->wait_max);
81 	PN(se->wait_sum);
82 	P(se->wait_count);
83 #endif
84 	P(se->load.weight);
85 #undef PN
86 #undef P
87 }
88 #endif
89 
90 static void
print_task(struct seq_file * m,struct rq * rq,struct task_struct * p)91 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
92 {
93 	if (rq->curr == p)
94 		SEQ_printf(m, "R");
95 	else
96 		SEQ_printf(m, " ");
97 
98 	SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
99 		p->comm, p->pid,
100 		SPLIT_NS(p->se.vruntime),
101 		(long long)(p->nvcsw + p->nivcsw),
102 		p->prio);
103 #ifdef CONFIG_SCHEDSTATS
104 	SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
105 		SPLIT_NS(p->se.vruntime),
106 		SPLIT_NS(p->se.sum_exec_runtime),
107 		SPLIT_NS(p->se.sum_sleep_runtime));
108 #else
109 	SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
110 		0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
111 #endif
112 
113 #ifdef CONFIG_CGROUP_SCHED
114 	{
115 		char path[64];
116 
117 		cgroup_path(task_group(p)->css.cgroup, path, sizeof(path));
118 		SEQ_printf(m, " %s", path);
119 	}
120 #endif
121 	SEQ_printf(m, "\n");
122 }
123 
print_rq(struct seq_file * m,struct rq * rq,int rq_cpu)124 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
125 {
126 	struct task_struct *g, *p;
127 	unsigned long flags;
128 
129 	SEQ_printf(m,
130 	"\nrunnable tasks:\n"
131 	"            task   PID         tree-key  switches  prio"
132 	"     exec-runtime         sum-exec        sum-sleep\n"
133 	"------------------------------------------------------"
134 	"----------------------------------------------------\n");
135 
136 	read_lock_irqsave(&tasklist_lock, flags);
137 
138 	do_each_thread(g, p) {
139 		if (!p->se.on_rq || task_cpu(p) != rq_cpu)
140 			continue;
141 
142 		print_task(m, rq, p);
143 	} while_each_thread(g, p);
144 
145 	read_unlock_irqrestore(&tasklist_lock, flags);
146 }
147 
148 #if defined(CONFIG_CGROUP_SCHED) && \
149 	(defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED))
task_group_path(struct task_group * tg,char * buf,int buflen)150 static void task_group_path(struct task_group *tg, char *buf, int buflen)
151 {
152 	/* may be NULL if the underlying cgroup isn't fully-created yet */
153 	if (!tg->css.cgroup) {
154 		buf[0] = '\0';
155 		return;
156 	}
157 	cgroup_path(tg->css.cgroup, buf, buflen);
158 }
159 #endif
160 
print_cfs_rq(struct seq_file * m,int cpu,struct cfs_rq * cfs_rq)161 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
162 {
163 	s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
164 		spread, rq0_min_vruntime, spread0;
165 	struct rq *rq = &per_cpu(runqueues, cpu);
166 	struct sched_entity *last;
167 	unsigned long flags;
168 
169 #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
170 	char path[128];
171 	struct task_group *tg = cfs_rq->tg;
172 
173 	task_group_path(tg, path, sizeof(path));
174 
175 	SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
176 #elif defined(CONFIG_USER_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
177 	{
178 		uid_t uid = cfs_rq->tg->uid;
179 		SEQ_printf(m, "\ncfs_rq[%d] for UID: %u\n", cpu, uid);
180 	}
181 #else
182 	SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
183 #endif
184 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
185 			SPLIT_NS(cfs_rq->exec_clock));
186 
187 	spin_lock_irqsave(&rq->lock, flags);
188 	if (cfs_rq->rb_leftmost)
189 		MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime;
190 	last = __pick_last_entity(cfs_rq);
191 	if (last)
192 		max_vruntime = last->vruntime;
193 	min_vruntime = cfs_rq->min_vruntime;
194 	rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime;
195 	spin_unlock_irqrestore(&rq->lock, flags);
196 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
197 			SPLIT_NS(MIN_vruntime));
198 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
199 			SPLIT_NS(min_vruntime));
200 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
201 			SPLIT_NS(max_vruntime));
202 	spread = max_vruntime - MIN_vruntime;
203 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
204 			SPLIT_NS(spread));
205 	spread0 = min_vruntime - rq0_min_vruntime;
206 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
207 			SPLIT_NS(spread0));
208 	SEQ_printf(m, "  .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
209 	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
210 
211 	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
212 			cfs_rq->nr_spread_over);
213 #ifdef CONFIG_FAIR_GROUP_SCHED
214 #ifdef CONFIG_SMP
215 	SEQ_printf(m, "  .%-30s: %lu\n", "shares", cfs_rq->shares);
216 #endif
217 	print_cfs_group_stats(m, cpu, cfs_rq->tg);
218 #endif
219 }
220 
print_rt_rq(struct seq_file * m,int cpu,struct rt_rq * rt_rq)221 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
222 {
223 #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
224 	char path[128];
225 	struct task_group *tg = rt_rq->tg;
226 
227 	task_group_path(tg, path, sizeof(path));
228 
229 	SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path);
230 #else
231 	SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
232 #endif
233 
234 
235 #define P(x) \
236 	SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
237 #define PN(x) \
238 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
239 
240 	P(rt_nr_running);
241 	P(rt_throttled);
242 	PN(rt_time);
243 	PN(rt_runtime);
244 
245 #undef PN
246 #undef P
247 }
248 
print_cpu(struct seq_file * m,int cpu)249 static void print_cpu(struct seq_file *m, int cpu)
250 {
251 	struct rq *rq = &per_cpu(runqueues, cpu);
252 
253 #ifdef CONFIG_X86
254 	{
255 		unsigned int freq = cpu_khz ? : 1;
256 
257 		SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
258 			   cpu, freq / 1000, (freq % 1000));
259 	}
260 #else
261 	SEQ_printf(m, "\ncpu#%d\n", cpu);
262 #endif
263 
264 #define P(x) \
265 	SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x))
266 #define PN(x) \
267 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
268 
269 	P(nr_running);
270 	SEQ_printf(m, "  .%-30s: %lu\n", "load",
271 		   rq->load.weight);
272 	P(nr_switches);
273 	P(nr_load_updates);
274 	P(nr_uninterruptible);
275 	SEQ_printf(m, "  .%-30s: %lu\n", "jiffies", jiffies);
276 	PN(next_balance);
277 	P(curr->pid);
278 	PN(clock);
279 	P(cpu_load[0]);
280 	P(cpu_load[1]);
281 	P(cpu_load[2]);
282 	P(cpu_load[3]);
283 	P(cpu_load[4]);
284 #undef P
285 #undef PN
286 
287 #ifdef CONFIG_SCHEDSTATS
288 #define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
289 
290 	P(yld_exp_empty);
291 	P(yld_act_empty);
292 	P(yld_both_empty);
293 	P(yld_count);
294 
295 	P(sched_switch);
296 	P(sched_count);
297 	P(sched_goidle);
298 
299 	P(ttwu_count);
300 	P(ttwu_local);
301 
302 	P(bkl_count);
303 
304 #undef P
305 #endif
306 	print_cfs_stats(m, cpu);
307 	print_rt_stats(m, cpu);
308 
309 	print_rq(m, rq, cpu);
310 }
311 
sched_debug_show(struct seq_file * m,void * v)312 static int sched_debug_show(struct seq_file *m, void *v)
313 {
314 	u64 now = ktime_to_ns(ktime_get());
315 	int cpu;
316 
317 	SEQ_printf(m, "Sched Debug Version: v0.08, %s %.*s\n",
318 		init_utsname()->release,
319 		(int)strcspn(init_utsname()->version, " "),
320 		init_utsname()->version);
321 
322 	SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now));
323 
324 #define P(x) \
325 	SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
326 #define PN(x) \
327 	SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
328 	PN(sysctl_sched_latency);
329 	PN(sysctl_sched_min_granularity);
330 	PN(sysctl_sched_wakeup_granularity);
331 	PN(sysctl_sched_child_runs_first);
332 	P(sysctl_sched_features);
333 #undef PN
334 #undef P
335 
336 	for_each_online_cpu(cpu)
337 		print_cpu(m, cpu);
338 
339 	SEQ_printf(m, "\n");
340 
341 	return 0;
342 }
343 
sysrq_sched_debug_show(void)344 static void sysrq_sched_debug_show(void)
345 {
346 	sched_debug_show(NULL, NULL);
347 }
348 
sched_debug_open(struct inode * inode,struct file * filp)349 static int sched_debug_open(struct inode *inode, struct file *filp)
350 {
351 	return single_open(filp, sched_debug_show, NULL);
352 }
353 
354 static const struct file_operations sched_debug_fops = {
355 	.open		= sched_debug_open,
356 	.read		= seq_read,
357 	.llseek		= seq_lseek,
358 	.release	= single_release,
359 };
360 
init_sched_debug_procfs(void)361 static int __init init_sched_debug_procfs(void)
362 {
363 	struct proc_dir_entry *pe;
364 
365 	pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
366 	if (!pe)
367 		return -ENOMEM;
368 	return 0;
369 }
370 
371 __initcall(init_sched_debug_procfs);
372 
proc_sched_show_task(struct task_struct * p,struct seq_file * m)373 void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
374 {
375 	unsigned long nr_switches;
376 	unsigned long flags;
377 	int num_threads = 1;
378 
379 	if (lock_task_sighand(p, &flags)) {
380 		num_threads = atomic_read(&p->signal->count);
381 		unlock_task_sighand(p, &flags);
382 	}
383 
384 	SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
385 	SEQ_printf(m,
386 		"---------------------------------------------------------\n");
387 #define __P(F) \
388 	SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
389 #define P(F) \
390 	SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
391 #define __PN(F) \
392 	SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
393 #define PN(F) \
394 	SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
395 
396 	PN(se.exec_start);
397 	PN(se.vruntime);
398 	PN(se.sum_exec_runtime);
399 	PN(se.avg_overlap);
400 
401 	nr_switches = p->nvcsw + p->nivcsw;
402 
403 #ifdef CONFIG_SCHEDSTATS
404 	PN(se.wait_start);
405 	PN(se.sleep_start);
406 	PN(se.block_start);
407 	PN(se.sleep_max);
408 	PN(se.block_max);
409 	PN(se.exec_max);
410 	PN(se.slice_max);
411 	PN(se.wait_max);
412 	PN(se.wait_sum);
413 	P(se.wait_count);
414 	P(sched_info.bkl_count);
415 	P(se.nr_migrations);
416 	P(se.nr_migrations_cold);
417 	P(se.nr_failed_migrations_affine);
418 	P(se.nr_failed_migrations_running);
419 	P(se.nr_failed_migrations_hot);
420 	P(se.nr_forced_migrations);
421 	P(se.nr_forced2_migrations);
422 	P(se.nr_wakeups);
423 	P(se.nr_wakeups_sync);
424 	P(se.nr_wakeups_migrate);
425 	P(se.nr_wakeups_local);
426 	P(se.nr_wakeups_remote);
427 	P(se.nr_wakeups_affine);
428 	P(se.nr_wakeups_affine_attempts);
429 	P(se.nr_wakeups_passive);
430 	P(se.nr_wakeups_idle);
431 
432 	{
433 		u64 avg_atom, avg_per_cpu;
434 
435 		avg_atom = p->se.sum_exec_runtime;
436 		if (nr_switches)
437 			do_div(avg_atom, nr_switches);
438 		else
439 			avg_atom = -1LL;
440 
441 		avg_per_cpu = p->se.sum_exec_runtime;
442 		if (p->se.nr_migrations) {
443 			avg_per_cpu = div64_u64(avg_per_cpu,
444 						p->se.nr_migrations);
445 		} else {
446 			avg_per_cpu = -1LL;
447 		}
448 
449 		__PN(avg_atom);
450 		__PN(avg_per_cpu);
451 	}
452 #endif
453 	__P(nr_switches);
454 	SEQ_printf(m, "%-35s:%21Ld\n",
455 		   "nr_voluntary_switches", (long long)p->nvcsw);
456 	SEQ_printf(m, "%-35s:%21Ld\n",
457 		   "nr_involuntary_switches", (long long)p->nivcsw);
458 
459 	P(se.load.weight);
460 	P(policy);
461 	P(prio);
462 #undef PN
463 #undef __PN
464 #undef P
465 #undef __P
466 
467 	{
468 		unsigned int this_cpu = raw_smp_processor_id();
469 		u64 t0, t1;
470 
471 		t0 = cpu_clock(this_cpu);
472 		t1 = cpu_clock(this_cpu);
473 		SEQ_printf(m, "%-35s:%21Ld\n",
474 			   "clock-delta", (long long)(t1-t0));
475 	}
476 }
477 
proc_sched_set_task(struct task_struct * p)478 void proc_sched_set_task(struct task_struct *p)
479 {
480 #ifdef CONFIG_SCHEDSTATS
481 	p->se.wait_max				= 0;
482 	p->se.wait_sum				= 0;
483 	p->se.wait_count			= 0;
484 	p->se.sleep_max				= 0;
485 	p->se.sum_sleep_runtime			= 0;
486 	p->se.block_max				= 0;
487 	p->se.exec_max				= 0;
488 	p->se.slice_max				= 0;
489 	p->se.nr_migrations			= 0;
490 	p->se.nr_migrations_cold		= 0;
491 	p->se.nr_failed_migrations_affine	= 0;
492 	p->se.nr_failed_migrations_running	= 0;
493 	p->se.nr_failed_migrations_hot		= 0;
494 	p->se.nr_forced_migrations		= 0;
495 	p->se.nr_forced2_migrations		= 0;
496 	p->se.nr_wakeups			= 0;
497 	p->se.nr_wakeups_sync			= 0;
498 	p->se.nr_wakeups_migrate		= 0;
499 	p->se.nr_wakeups_local			= 0;
500 	p->se.nr_wakeups_remote			= 0;
501 	p->se.nr_wakeups_affine			= 0;
502 	p->se.nr_wakeups_affine_attempts	= 0;
503 	p->se.nr_wakeups_passive		= 0;
504 	p->se.nr_wakeups_idle			= 0;
505 	p->sched_info.bkl_count			= 0;
506 #endif
507 	p->se.sum_exec_runtime			= 0;
508 	p->se.prev_sum_exec_runtime		= 0;
509 	p->nvcsw				= 0;
510 	p->nivcsw				= 0;
511 }
512