These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / kernel / sched / debug.c
1 /*
2  * kernel/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 #include <linux/mempolicy.h>
19
20 #include "sched.h"
21
22 static DEFINE_SPINLOCK(sched_debug_lock);
23
24 /*
25  * This allows printing both to /proc/sched_debug and
26  * to the console
27  */
28 #define SEQ_printf(m, x...)                     \
29  do {                                           \
30         if (m)                                  \
31                 seq_printf(m, x);               \
32         else                                    \
33                 printk(x);                      \
34  } while (0)
35
36 /*
37  * Ease the printing of nsec fields:
38  */
39 static long long nsec_high(unsigned long long nsec)
40 {
41         if ((long long)nsec < 0) {
42                 nsec = -nsec;
43                 do_div(nsec, 1000000);
44                 return -nsec;
45         }
46         do_div(nsec, 1000000);
47
48         return nsec;
49 }
50
51 static unsigned long nsec_low(unsigned long long nsec)
52 {
53         if ((long long)nsec < 0)
54                 nsec = -nsec;
55
56         return do_div(nsec, 1000000);
57 }
58
59 #define SPLIT_NS(x) nsec_high(x), nsec_low(x)
60
61 #ifdef CONFIG_FAIR_GROUP_SCHED
62 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
63 {
64         struct sched_entity *se = tg->se[cpu];
65
66 #define P(F) \
67         SEQ_printf(m, "  .%-30s: %lld\n", #F, (long long)F)
68 #define PN(F) \
69         SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
70
71         if (!se)
72                 return;
73
74         PN(se->exec_start);
75         PN(se->vruntime);
76         PN(se->sum_exec_runtime);
77 #ifdef CONFIG_SCHEDSTATS
78         PN(se->statistics.wait_start);
79         PN(se->statistics.sleep_start);
80         PN(se->statistics.block_start);
81         PN(se->statistics.sleep_max);
82         PN(se->statistics.block_max);
83         PN(se->statistics.exec_max);
84         PN(se->statistics.slice_max);
85         PN(se->statistics.wait_max);
86         PN(se->statistics.wait_sum);
87         P(se->statistics.wait_count);
88 #endif
89         P(se->load.weight);
90 #ifdef CONFIG_SMP
91         P(se->avg.load_avg);
92         P(se->avg.util_avg);
93 #endif
94 #undef PN
95 #undef P
96 }
97 #endif
98
99 #ifdef CONFIG_CGROUP_SCHED
100 static char group_path[PATH_MAX];
101
102 static char *task_group_path(struct task_group *tg)
103 {
104         if (autogroup_path(tg, group_path, PATH_MAX))
105                 return group_path;
106
107         return cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
108 }
109 #endif
110
111 static void
112 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
113 {
114         if (rq->curr == p)
115                 SEQ_printf(m, "R");
116         else
117                 SEQ_printf(m, " ");
118
119         SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
120                 p->comm, task_pid_nr(p),
121                 SPLIT_NS(p->se.vruntime),
122                 (long long)(p->nvcsw + p->nivcsw),
123                 p->prio);
124 #ifdef CONFIG_SCHEDSTATS
125         SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
126                 SPLIT_NS(p->se.statistics.wait_sum),
127                 SPLIT_NS(p->se.sum_exec_runtime),
128                 SPLIT_NS(p->se.statistics.sum_sleep_runtime));
129 #else
130         SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
131                 0LL, 0L,
132                 SPLIT_NS(p->se.sum_exec_runtime),
133                 0LL, 0L);
134 #endif
135 #ifdef CONFIG_NUMA_BALANCING
136         SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
137 #endif
138 #ifdef CONFIG_CGROUP_SCHED
139         SEQ_printf(m, " %s", task_group_path(task_group(p)));
140 #endif
141
142         SEQ_printf(m, "\n");
143 }
144
145 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
146 {
147         struct task_struct *g, *p;
148
149         SEQ_printf(m,
150         "\nrunnable tasks:\n"
151         "            task   PID         tree-key  switches  prio"
152         "     wait-time             sum-exec        sum-sleep\n"
153         "------------------------------------------------------"
154         "----------------------------------------------------\n");
155
156         rcu_read_lock();
157         for_each_process_thread(g, p) {
158                 if (task_cpu(p) != rq_cpu)
159                         continue;
160
161                 print_task(m, rq, p);
162         }
163         rcu_read_unlock();
164 }
165
166 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
167 {
168         s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
169                 spread, rq0_min_vruntime, spread0;
170         struct rq *rq = cpu_rq(cpu);
171         struct sched_entity *last;
172         unsigned long flags;
173
174 #ifdef CONFIG_FAIR_GROUP_SCHED
175         SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
176 #else
177         SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
178 #endif
179         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
180                         SPLIT_NS(cfs_rq->exec_clock));
181
182         raw_spin_lock_irqsave(&rq->lock, flags);
183         if (cfs_rq->rb_leftmost)
184                 MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
185         last = __pick_last_entity(cfs_rq);
186         if (last)
187                 max_vruntime = last->vruntime;
188         min_vruntime = cfs_rq->min_vruntime;
189         rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
190         raw_spin_unlock_irqrestore(&rq->lock, flags);
191         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
192                         SPLIT_NS(MIN_vruntime));
193         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
194                         SPLIT_NS(min_vruntime));
195         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
196                         SPLIT_NS(max_vruntime));
197         spread = max_vruntime - MIN_vruntime;
198         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
199                         SPLIT_NS(spread));
200         spread0 = min_vruntime - rq0_min_vruntime;
201         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
202                         SPLIT_NS(spread0));
203         SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
204                         cfs_rq->nr_spread_over);
205         SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
206         SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
207 #ifdef CONFIG_SMP
208         SEQ_printf(m, "  .%-30s: %lu\n", "load_avg",
209                         cfs_rq->avg.load_avg);
210         SEQ_printf(m, "  .%-30s: %lu\n", "runnable_load_avg",
211                         cfs_rq->runnable_load_avg);
212         SEQ_printf(m, "  .%-30s: %lu\n", "util_avg",
213                         cfs_rq->avg.util_avg);
214         SEQ_printf(m, "  .%-30s: %ld\n", "removed_load_avg",
215                         atomic_long_read(&cfs_rq->removed_load_avg));
216         SEQ_printf(m, "  .%-30s: %ld\n", "removed_util_avg",
217                         atomic_long_read(&cfs_rq->removed_util_avg));
218 #ifdef CONFIG_FAIR_GROUP_SCHED
219         SEQ_printf(m, "  .%-30s: %lu\n", "tg_load_avg_contrib",
220                         cfs_rq->tg_load_avg_contrib);
221         SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_avg",
222                         atomic_long_read(&cfs_rq->tg->load_avg));
223 #endif
224 #endif
225 #ifdef CONFIG_CFS_BANDWIDTH
226         SEQ_printf(m, "  .%-30s: %d\n", "throttled",
227                         cfs_rq->throttled);
228         SEQ_printf(m, "  .%-30s: %d\n", "throttle_count",
229                         cfs_rq->throttle_count);
230 #endif
231
232 #ifdef CONFIG_FAIR_GROUP_SCHED
233         print_cfs_group_stats(m, cpu, cfs_rq->tg);
234 #endif
235 }
236
237 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
238 {
239 #ifdef CONFIG_RT_GROUP_SCHED
240         SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
241 #else
242         SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
243 #endif
244
245 #define P(x) \
246         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
247 #define PN(x) \
248         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
249
250         P(rt_nr_running);
251         P(rt_throttled);
252         PN(rt_time);
253         PN(rt_runtime);
254 #ifdef CONFIG_SMP
255         P(rt_nr_migratory);
256 #endif
257
258 #undef PN
259 #undef P
260 }
261
262 void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
263 {
264         SEQ_printf(m, "\ndl_rq[%d]:\n", cpu);
265         SEQ_printf(m, "  .%-30s: %ld\n", "dl_nr_running", dl_rq->dl_nr_running);
266 }
267
268 extern __read_mostly int sched_clock_running;
269
270 static void print_cpu(struct seq_file *m, int cpu)
271 {
272         struct rq *rq = cpu_rq(cpu);
273         unsigned long flags;
274
275 #ifdef CONFIG_X86
276         {
277                 unsigned int freq = cpu_khz ? : 1;
278
279                 SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
280                            cpu, freq / 1000, (freq % 1000));
281         }
282 #else
283         SEQ_printf(m, "cpu#%d\n", cpu);
284 #endif
285
286 #define P(x)                                                            \
287 do {                                                                    \
288         if (sizeof(rq->x) == 4)                                         \
289                 SEQ_printf(m, "  .%-30s: %ld\n", #x, (long)(rq->x));    \
290         else                                                            \
291                 SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x));\
292 } while (0)
293
294 #define PN(x) \
295         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
296
297         P(nr_running);
298         SEQ_printf(m, "  .%-30s: %lu\n", "load",
299                    rq->load.weight);
300         P(nr_switches);
301         P(nr_load_updates);
302         P(nr_uninterruptible);
303         PN(next_balance);
304         SEQ_printf(m, "  .%-30s: %ld\n", "curr->pid", (long)(task_pid_nr(rq->curr)));
305         PN(clock);
306         PN(clock_task);
307         P(cpu_load[0]);
308         P(cpu_load[1]);
309         P(cpu_load[2]);
310         P(cpu_load[3]);
311         P(cpu_load[4]);
312 #undef P
313 #undef PN
314
315 #ifdef CONFIG_SCHEDSTATS
316 #define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
317 #define P64(n) SEQ_printf(m, "  .%-30s: %Ld\n", #n, rq->n);
318
319         P(yld_count);
320
321         P(sched_count);
322         P(sched_goidle);
323 #ifdef CONFIG_SMP
324         P64(avg_idle);
325         P64(max_idle_balance_cost);
326 #endif
327
328         P(ttwu_count);
329         P(ttwu_local);
330
331 #undef P
332 #undef P64
333 #endif
334         spin_lock_irqsave(&sched_debug_lock, flags);
335         print_cfs_stats(m, cpu);
336         print_rt_stats(m, cpu);
337         print_dl_stats(m, cpu);
338
339         print_rq(m, rq, cpu);
340         spin_unlock_irqrestore(&sched_debug_lock, flags);
341         SEQ_printf(m, "\n");
342 }
343
344 static const char *sched_tunable_scaling_names[] = {
345         "none",
346         "logaritmic",
347         "linear"
348 };
349
350 static void sched_debug_header(struct seq_file *m)
351 {
352         u64 ktime, sched_clk, cpu_clk;
353         unsigned long flags;
354
355         local_irq_save(flags);
356         ktime = ktime_to_ns(ktime_get());
357         sched_clk = sched_clock();
358         cpu_clk = local_clock();
359         local_irq_restore(flags);
360
361         SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n",
362                 init_utsname()->release,
363                 (int)strcspn(init_utsname()->version, " "),
364                 init_utsname()->version);
365
366 #define P(x) \
367         SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
368 #define PN(x) \
369         SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
370         PN(ktime);
371         PN(sched_clk);
372         PN(cpu_clk);
373         P(jiffies);
374 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
375         P(sched_clock_stable());
376 #endif
377 #undef PN
378 #undef P
379
380         SEQ_printf(m, "\n");
381         SEQ_printf(m, "sysctl_sched\n");
382
383 #define P(x) \
384         SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
385 #define PN(x) \
386         SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
387         PN(sysctl_sched_latency);
388         PN(sysctl_sched_min_granularity);
389         PN(sysctl_sched_wakeup_granularity);
390         P(sysctl_sched_child_runs_first);
391         P(sysctl_sched_features);
392 #undef PN
393 #undef P
394
395         SEQ_printf(m, "  .%-40s: %d (%s)\n",
396                 "sysctl_sched_tunable_scaling",
397                 sysctl_sched_tunable_scaling,
398                 sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
399         SEQ_printf(m, "\n");
400 }
401
402 static int sched_debug_show(struct seq_file *m, void *v)
403 {
404         int cpu = (unsigned long)(v - 2);
405
406         if (cpu != -1)
407                 print_cpu(m, cpu);
408         else
409                 sched_debug_header(m);
410
411         return 0;
412 }
413
414 void sysrq_sched_debug_show(void)
415 {
416         int cpu;
417
418         sched_debug_header(NULL);
419         for_each_online_cpu(cpu)
420                 print_cpu(NULL, cpu);
421
422 }
423
424 /*
425  * This itererator needs some explanation.
426  * It returns 1 for the header position.
427  * This means 2 is cpu 0.
428  * In a hotplugged system some cpus, including cpu 0, may be missing so we have
429  * to use cpumask_* to iterate over the cpus.
430  */
431 static void *sched_debug_start(struct seq_file *file, loff_t *offset)
432 {
433         unsigned long n = *offset;
434
435         if (n == 0)
436                 return (void *) 1;
437
438         n--;
439
440         if (n > 0)
441                 n = cpumask_next(n - 1, cpu_online_mask);
442         else
443                 n = cpumask_first(cpu_online_mask);
444
445         *offset = n + 1;
446
447         if (n < nr_cpu_ids)
448                 return (void *)(unsigned long)(n + 2);
449         return NULL;
450 }
451
452 static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
453 {
454         (*offset)++;
455         return sched_debug_start(file, offset);
456 }
457
458 static void sched_debug_stop(struct seq_file *file, void *data)
459 {
460 }
461
462 static const struct seq_operations sched_debug_sops = {
463         .start = sched_debug_start,
464         .next = sched_debug_next,
465         .stop = sched_debug_stop,
466         .show = sched_debug_show,
467 };
468
469 static int sched_debug_release(struct inode *inode, struct file *file)
470 {
471         seq_release(inode, file);
472
473         return 0;
474 }
475
476 static int sched_debug_open(struct inode *inode, struct file *filp)
477 {
478         int ret = 0;
479
480         ret = seq_open(filp, &sched_debug_sops);
481
482         return ret;
483 }
484
485 static const struct file_operations sched_debug_fops = {
486         .open           = sched_debug_open,
487         .read           = seq_read,
488         .llseek         = seq_lseek,
489         .release        = sched_debug_release,
490 };
491
492 static int __init init_sched_debug_procfs(void)
493 {
494         struct proc_dir_entry *pe;
495
496         pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
497         if (!pe)
498                 return -ENOMEM;
499         return 0;
500 }
501
502 __initcall(init_sched_debug_procfs);
503
504 #define __P(F) \
505         SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
506 #define P(F) \
507         SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
508 #define __PN(F) \
509         SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
510 #define PN(F) \
511         SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
512
513
514 #ifdef CONFIG_NUMA_BALANCING
515 void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
516                 unsigned long tpf, unsigned long gsf, unsigned long gpf)
517 {
518         SEQ_printf(m, "numa_faults node=%d ", node);
519         SEQ_printf(m, "task_private=%lu task_shared=%lu ", tsf, tpf);
520         SEQ_printf(m, "group_private=%lu group_shared=%lu\n", gsf, gpf);
521 }
522 #endif
523
524
525 static void sched_show_numa(struct task_struct *p, struct seq_file *m)
526 {
527 #ifdef CONFIG_NUMA_BALANCING
528         struct mempolicy *pol;
529
530         if (p->mm)
531                 P(mm->numa_scan_seq);
532
533         task_lock(p);
534         pol = p->mempolicy;
535         if (pol && !(pol->flags & MPOL_F_MORON))
536                 pol = NULL;
537         mpol_get(pol);
538         task_unlock(p);
539
540         P(numa_pages_migrated);
541         P(numa_preferred_nid);
542         P(total_numa_faults);
543         SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
544                         task_node(p), task_numa_group_id(p));
545         show_numa_stats(p, m);
546         mpol_put(pol);
547 #endif
548 }
549
550 void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
551 {
552         unsigned long nr_switches;
553
554         SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr(p),
555                                                 get_nr_threads(p));
556         SEQ_printf(m,
557                 "---------------------------------------------------------"
558                 "----------\n");
559 #define __P(F) \
560         SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
561 #define P(F) \
562         SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
563 #define __PN(F) \
564         SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
565 #define PN(F) \
566         SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
567
568         PN(se.exec_start);
569         PN(se.vruntime);
570         PN(se.sum_exec_runtime);
571
572         nr_switches = p->nvcsw + p->nivcsw;
573
574 #ifdef CONFIG_SCHEDSTATS
575         PN(se.statistics.sum_sleep_runtime);
576         PN(se.statistics.wait_start);
577         PN(se.statistics.sleep_start);
578         PN(se.statistics.block_start);
579         PN(se.statistics.sleep_max);
580         PN(se.statistics.block_max);
581         PN(se.statistics.exec_max);
582         PN(se.statistics.slice_max);
583         PN(se.statistics.wait_max);
584         PN(se.statistics.wait_sum);
585         P(se.statistics.wait_count);
586         PN(se.statistics.iowait_sum);
587         P(se.statistics.iowait_count);
588         P(se.nr_migrations);
589         P(se.statistics.nr_migrations_cold);
590         P(se.statistics.nr_failed_migrations_affine);
591         P(se.statistics.nr_failed_migrations_running);
592         P(se.statistics.nr_failed_migrations_hot);
593         P(se.statistics.nr_forced_migrations);
594         P(se.statistics.nr_wakeups);
595         P(se.statistics.nr_wakeups_sync);
596         P(se.statistics.nr_wakeups_migrate);
597         P(se.statistics.nr_wakeups_local);
598         P(se.statistics.nr_wakeups_remote);
599         P(se.statistics.nr_wakeups_affine);
600         P(se.statistics.nr_wakeups_affine_attempts);
601         P(se.statistics.nr_wakeups_passive);
602         P(se.statistics.nr_wakeups_idle);
603
604         {
605                 u64 avg_atom, avg_per_cpu;
606
607                 avg_atom = p->se.sum_exec_runtime;
608                 if (nr_switches)
609                         avg_atom = div64_ul(avg_atom, nr_switches);
610                 else
611                         avg_atom = -1LL;
612
613                 avg_per_cpu = p->se.sum_exec_runtime;
614                 if (p->se.nr_migrations) {
615                         avg_per_cpu = div64_u64(avg_per_cpu,
616                                                 p->se.nr_migrations);
617                 } else {
618                         avg_per_cpu = -1LL;
619                 }
620
621                 __PN(avg_atom);
622                 __PN(avg_per_cpu);
623         }
624 #endif
625         __P(nr_switches);
626         SEQ_printf(m, "%-45s:%21Ld\n",
627                    "nr_voluntary_switches", (long long)p->nvcsw);
628         SEQ_printf(m, "%-45s:%21Ld\n",
629                    "nr_involuntary_switches", (long long)p->nivcsw);
630
631         P(se.load.weight);
632 #ifdef CONFIG_SMP
633         P(se.avg.load_sum);
634         P(se.avg.util_sum);
635         P(se.avg.load_avg);
636         P(se.avg.util_avg);
637         P(se.avg.last_update_time);
638 #endif
639         P(policy);
640         P(prio);
641 #ifdef CONFIG_PREEMPT_RT_FULL
642         P(migrate_disable);
643 #endif
644         P(nr_cpus_allowed);
645 #undef PN
646 #undef __PN
647 #undef P
648 #undef __P
649
650         {
651                 unsigned int this_cpu = raw_smp_processor_id();
652                 u64 t0, t1;
653
654                 t0 = cpu_clock(this_cpu);
655                 t1 = cpu_clock(this_cpu);
656                 SEQ_printf(m, "%-45s:%21Ld\n",
657                            "clock-delta", (long long)(t1-t0));
658         }
659
660         sched_show_numa(p, m);
661 }
662
663 void proc_sched_set_task(struct task_struct *p)
664 {
665 #ifdef CONFIG_SCHEDSTATS
666         memset(&p->se.statistics, 0, sizeof(p->se.statistics));
667 #endif
668 }