Root/kernel/sched_debug.c

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
19static DEFINE_SPINLOCK(sched_debug_lock);
20
21/*
22 * This allows printing both to /proc/sched_debug and
23 * to the console
24 */
25#define SEQ_printf(m, x...) \
26 do { \
27    if (m) \
28        seq_printf(m, x); \
29    else \
30        printk(x); \
31 } while (0)
32
33/*
34 * Ease the printing of nsec fields:
35 */
36static long long nsec_high(unsigned long long nsec)
37{
38    if ((long long)nsec < 0) {
39        nsec = -nsec;
40        do_div(nsec, 1000000);
41        return -nsec;
42    }
43    do_div(nsec, 1000000);
44
45    return nsec;
46}
47
48static unsigned long nsec_low(unsigned long long nsec)
49{
50    if ((long long)nsec < 0)
51        nsec = -nsec;
52
53    return do_div(nsec, 1000000);
54}
55
56#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
57
58#ifdef CONFIG_FAIR_GROUP_SCHED
59static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
60{
61    struct sched_entity *se = tg->se[cpu];
62    if (!se)
63        return;
64
65#define P(F) \
66    SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
67#define PN(F) \
68    SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
69
70    PN(se->exec_start);
71    PN(se->vruntime);
72    PN(se->sum_exec_runtime);
73#ifdef CONFIG_SCHEDSTATS
74    PN(se->statistics.wait_start);
75    PN(se->statistics.sleep_start);
76    PN(se->statistics.block_start);
77    PN(se->statistics.sleep_max);
78    PN(se->statistics.block_max);
79    PN(se->statistics.exec_max);
80    PN(se->statistics.slice_max);
81    PN(se->statistics.wait_max);
82    PN(se->statistics.wait_sum);
83    P(se->statistics.wait_count);
84#endif
85    P(se->load.weight);
86#undef PN
87#undef P
88}
89#endif
90
91#ifdef CONFIG_CGROUP_SCHED
92static char group_path[PATH_MAX];
93
94static char *task_group_path(struct task_group *tg)
95{
96    if (autogroup_path(tg, group_path, PATH_MAX))
97        return group_path;
98
99    /*
100     * May be NULL if the underlying cgroup isn't fully-created yet
101     */
102    if (!tg->css.cgroup) {
103        group_path[0] = '\0';
104        return group_path;
105    }
106    cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
107    return group_path;
108}
109#endif
110
111static void
112print_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, p->pid,
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.vruntime),
127        SPLIT_NS(p->se.sum_exec_runtime),
128        SPLIT_NS(p->se.statistics.sum_sleep_runtime));
129#else
130    SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
131        0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
132#endif
133#ifdef CONFIG_CGROUP_SCHED
134    SEQ_printf(m, " %s", task_group_path(task_group(p)));
135#endif
136
137    SEQ_printf(m, "\n");
138}
139
140static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
141{
142    struct task_struct *g, *p;
143    unsigned long flags;
144
145    SEQ_printf(m,
146    "\nrunnable tasks:\n"
147    " task PID tree-key switches prio"
148    " exec-runtime sum-exec sum-sleep\n"
149    "------------------------------------------------------"
150    "----------------------------------------------------\n");
151
152    read_lock_irqsave(&tasklist_lock, flags);
153
154    do_each_thread(g, p) {
155        if (!p->on_rq || task_cpu(p) != rq_cpu)
156            continue;
157
158        print_task(m, rq, p);
159    } while_each_thread(g, p);
160
161    read_unlock_irqrestore(&tasklist_lock, flags);
162}
163
164void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
165{
166    s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
167        spread, rq0_min_vruntime, spread0;
168    struct rq *rq = cpu_rq(cpu);
169    struct sched_entity *last;
170    unsigned long flags;
171
172#ifdef CONFIG_FAIR_GROUP_SCHED
173    SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
174#else
175    SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
176#endif
177    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
178            SPLIT_NS(cfs_rq->exec_clock));
179
180    raw_spin_lock_irqsave(&rq->lock, flags);
181    if (cfs_rq->rb_leftmost)
182        MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
183    last = __pick_last_entity(cfs_rq);
184    if (last)
185        max_vruntime = last->vruntime;
186    min_vruntime = cfs_rq->min_vruntime;
187    rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
188    raw_spin_unlock_irqrestore(&rq->lock, flags);
189    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime",
190            SPLIT_NS(MIN_vruntime));
191    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime",
192            SPLIT_NS(min_vruntime));
193    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "max_vruntime",
194            SPLIT_NS(max_vruntime));
195    spread = max_vruntime - MIN_vruntime;
196    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread",
197            SPLIT_NS(spread));
198    spread0 = min_vruntime - rq0_min_vruntime;
199    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread0",
200            SPLIT_NS(spread0));
201    SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over",
202            cfs_rq->nr_spread_over);
203    SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
204    SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
205#ifdef CONFIG_FAIR_GROUP_SCHED
206#ifdef CONFIG_SMP
207    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "load_avg",
208            SPLIT_NS(cfs_rq->load_avg));
209    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "load_period",
210            SPLIT_NS(cfs_rq->load_period));
211    SEQ_printf(m, " .%-30s: %ld\n", "load_contrib",
212            cfs_rq->load_contribution);
213    SEQ_printf(m, " .%-30s: %d\n", "load_tg",
214            atomic_read(&cfs_rq->tg->load_weight));
215#endif
216
217    print_cfs_group_stats(m, cpu, cfs_rq->tg);
218#endif
219}
220
221void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
222{
223#ifdef CONFIG_RT_GROUP_SCHED
224    SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
225#else
226    SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
227#endif
228
229#define P(x) \
230    SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
231#define PN(x) \
232    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
233
234    P(rt_nr_running);
235    P(rt_throttled);
236    PN(rt_time);
237    PN(rt_runtime);
238
239#undef PN
240#undef P
241}
242
243extern __read_mostly int sched_clock_running;
244
245static void print_cpu(struct seq_file *m, int cpu)
246{
247    struct rq *rq = cpu_rq(cpu);
248    unsigned long flags;
249
250#ifdef CONFIG_X86
251    {
252        unsigned int freq = cpu_khz ? : 1;
253
254        SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
255               cpu, freq / 1000, (freq % 1000));
256    }
257#else
258    SEQ_printf(m, "\ncpu#%d\n", cpu);
259#endif
260
261#define P(x) \
262    SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x))
263#define PN(x) \
264    SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
265
266    P(nr_running);
267    SEQ_printf(m, " .%-30s: %lu\n", "load",
268           rq->load.weight);
269    P(nr_switches);
270    P(nr_load_updates);
271    P(nr_uninterruptible);
272    PN(next_balance);
273    P(curr->pid);
274    PN(clock);
275    P(cpu_load[0]);
276    P(cpu_load[1]);
277    P(cpu_load[2]);
278    P(cpu_load[3]);
279    P(cpu_load[4]);
280#undef P
281#undef PN
282
283#ifdef CONFIG_SCHEDSTATS
284#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
285#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
286
287    P(yld_count);
288
289    P(sched_switch);
290    P(sched_count);
291    P(sched_goidle);
292#ifdef CONFIG_SMP
293    P64(avg_idle);
294#endif
295
296    P(ttwu_count);
297    P(ttwu_local);
298
299#undef P
300#undef P64
301#endif
302    spin_lock_irqsave(&sched_debug_lock, flags);
303    print_cfs_stats(m, cpu);
304    print_rt_stats(m, cpu);
305
306    rcu_read_lock();
307    print_rq(m, rq, cpu);
308    rcu_read_unlock();
309    spin_unlock_irqrestore(&sched_debug_lock, flags);
310}
311
312static const char *sched_tunable_scaling_names[] = {
313    "none",
314    "logaritmic",
315    "linear"
316};
317
318static int sched_debug_show(struct seq_file *m, void *v)
319{
320    u64 ktime, sched_clk, cpu_clk;
321    unsigned long flags;
322    int cpu;
323
324    local_irq_save(flags);
325    ktime = ktime_to_ns(ktime_get());
326    sched_clk = sched_clock();
327    cpu_clk = local_clock();
328    local_irq_restore(flags);
329
330    SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
331        init_utsname()->release,
332        (int)strcspn(init_utsname()->version, " "),
333        init_utsname()->version);
334
335#define P(x) \
336    SEQ_printf(m, "%-40s: %Ld\n", #x, (long long)(x))
337#define PN(x) \
338    SEQ_printf(m, "%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
339    PN(ktime);
340    PN(sched_clk);
341    PN(cpu_clk);
342    P(jiffies);
343#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
344    P(sched_clock_stable);
345#endif
346#undef PN
347#undef P
348
349    SEQ_printf(m, "\n");
350    SEQ_printf(m, "sysctl_sched\n");
351
352#define P(x) \
353    SEQ_printf(m, " .%-40s: %Ld\n", #x, (long long)(x))
354#define PN(x) \
355    SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
356    PN(sysctl_sched_latency);
357    PN(sysctl_sched_min_granularity);
358    PN(sysctl_sched_wakeup_granularity);
359    P(sysctl_sched_child_runs_first);
360    P(sysctl_sched_features);
361#undef PN
362#undef P
363
364    SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
365        sysctl_sched_tunable_scaling,
366        sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
367
368    for_each_online_cpu(cpu)
369        print_cpu(m, cpu);
370
371    SEQ_printf(m, "\n");
372
373    return 0;
374}
375
376static void sysrq_sched_debug_show(void)
377{
378    sched_debug_show(NULL, NULL);
379}
380
381static int sched_debug_open(struct inode *inode, struct file *filp)
382{
383    return single_open(filp, sched_debug_show, NULL);
384}
385
386static const struct file_operations sched_debug_fops = {
387    .open = sched_debug_open,
388    .read = seq_read,
389    .llseek = seq_lseek,
390    .release = single_release,
391};
392
393static int __init init_sched_debug_procfs(void)
394{
395    struct proc_dir_entry *pe;
396
397    pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
398    if (!pe)
399        return -ENOMEM;
400    return 0;
401}
402
403__initcall(init_sched_debug_procfs);
404
405void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
406{
407    unsigned long nr_switches;
408
409    SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
410                        get_nr_threads(p));
411    SEQ_printf(m,
412        "---------------------------------------------------------\n");
413#define __P(F) \
414    SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
415#define P(F) \
416    SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
417#define __PN(F) \
418    SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
419#define PN(F) \
420    SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
421
422    PN(se.exec_start);
423    PN(se.vruntime);
424    PN(se.sum_exec_runtime);
425
426    nr_switches = p->nvcsw + p->nivcsw;
427
428#ifdef CONFIG_SCHEDSTATS
429    PN(se.statistics.wait_start);
430    PN(se.statistics.sleep_start);
431    PN(se.statistics.block_start);
432    PN(se.statistics.sleep_max);
433    PN(se.statistics.block_max);
434    PN(se.statistics.exec_max);
435    PN(se.statistics.slice_max);
436    PN(se.statistics.wait_max);
437    PN(se.statistics.wait_sum);
438    P(se.statistics.wait_count);
439    PN(se.statistics.iowait_sum);
440    P(se.statistics.iowait_count);
441    P(se.nr_migrations);
442    P(se.statistics.nr_migrations_cold);
443    P(se.statistics.nr_failed_migrations_affine);
444    P(se.statistics.nr_failed_migrations_running);
445    P(se.statistics.nr_failed_migrations_hot);
446    P(se.statistics.nr_forced_migrations);
447    P(se.statistics.nr_wakeups);
448    P(se.statistics.nr_wakeups_sync);
449    P(se.statistics.nr_wakeups_migrate);
450    P(se.statistics.nr_wakeups_local);
451    P(se.statistics.nr_wakeups_remote);
452    P(se.statistics.nr_wakeups_affine);
453    P(se.statistics.nr_wakeups_affine_attempts);
454    P(se.statistics.nr_wakeups_passive);
455    P(se.statistics.nr_wakeups_idle);
456
457    {
458        u64 avg_atom, avg_per_cpu;
459
460        avg_atom = p->se.sum_exec_runtime;
461        if (nr_switches)
462            do_div(avg_atom, nr_switches);
463        else
464            avg_atom = -1LL;
465
466        avg_per_cpu = p->se.sum_exec_runtime;
467        if (p->se.nr_migrations) {
468            avg_per_cpu = div64_u64(avg_per_cpu,
469                        p->se.nr_migrations);
470        } else {
471            avg_per_cpu = -1LL;
472        }
473
474        __PN(avg_atom);
475        __PN(avg_per_cpu);
476    }
477#endif
478    __P(nr_switches);
479    SEQ_printf(m, "%-35s:%21Ld\n",
480           "nr_voluntary_switches", (long long)p->nvcsw);
481    SEQ_printf(m, "%-35s:%21Ld\n",
482           "nr_involuntary_switches", (long long)p->nivcsw);
483
484    P(se.load.weight);
485    P(policy);
486    P(prio);
487#undef PN
488#undef __PN
489#undef P
490#undef __P
491
492    {
493        unsigned int this_cpu = raw_smp_processor_id();
494        u64 t0, t1;
495
496        t0 = cpu_clock(this_cpu);
497        t1 = cpu_clock(this_cpu);
498        SEQ_printf(m, "%-35s:%21Ld\n",
499               "clock-delta", (long long)(t1-t0));
500    }
501}
502
503void proc_sched_set_task(struct task_struct *p)
504{
505#ifdef CONFIG_SCHEDSTATS
506    memset(&p->se.statistics, 0, sizeof(p->se.statistics));
507#endif
508}
509

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