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
  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 static void
  32 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p, u64 now)
  33 {
  34         if (rq->curr == p)
  35                 SEQ_printf(m, "R");
  36         else
  37                 SEQ_printf(m, " ");
  38
  39         SEQ_printf(m, "%15s %5d %15Ld %13Ld %13Ld %9Ld %5d "
  40                       "%15Ld %15Ld %15Ld %15Ld %15Ld\n",
  41                 p->comm, p->pid,
  42                 (long long)p->se.fair_key,
  43                 (long long)(p->se.fair_key - rq->cfs.fair_clock),
  44                 (long long)p->se.wait_runtime,
  45                 (long long)(p->nvcsw + p->nivcsw),
  46                 p->prio,
  47                 (long long)p->se.sum_exec_runtime,
  48                 (long long)p->se.sum_wait_runtime,
  49                 (long long)p->se.sum_sleep_runtime,
  50                 (long long)p->se.wait_runtime_overruns,
  51                 (long long)p->se.wait_runtime_underruns);
  52 }
  53
  54 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu, u64 now)
  55 {
  56         struct task_struct *g, *p;
  57
  58         SEQ_printf(m,
  59         "\nrunnable tasks:\n"
  60         "            task   PID        tree-key         delta       waiting"
  61         "  switches  prio"
  62         "        sum-exec        sum-wait       sum-sleep"
  63         "    wait-overrun   wait-underrun\n"
  64         "------------------------------------------------------------------"
  65         "----------------"
  66         "------------------------------------------------"
  67         "--------------------------------\n");
  68
  69         read_lock_irq(&tasklist_lock);
  70
  71         do_each_thread(g, p) {
  72                 if (!p->se.on_rq || task_cpu(p) != rq_cpu)
  73                         continue;
  74
  75                 print_task(m, rq, p, now);
  76         } while_each_thread(g, p);
  77
  78         read_unlock_irq(&tasklist_lock);
  79 }
  80
  81 static void
  82 print_cfs_rq_runtime_sum(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
  83 {
  84         s64 wait_runtime_rq_sum = 0;
  85         struct task_struct *p;
  86         struct rb_node *curr;
  87         unsigned long flags;
  88         struct rq *rq = &per_cpu(runqueues, cpu);
  89
  90         spin_lock_irqsave(&rq->lock, flags);
  91         curr = first_fair(cfs_rq);
  92         while (curr) {
  93                 p = rb_entry(curr, struct task_struct, se.run_node);
  94                 wait_runtime_rq_sum += p->se.wait_runtime;
  95
  96                 curr = rb_next(curr);
  97         }
  98         spin_unlock_irqrestore(&rq->lock, flags);
  99
 100         SEQ_printf(m, "  .%-30s: %Ld\n", "wait_runtime_rq_sum",
 101                 (long long)wait_runtime_rq_sum);
 102 }
 103
 104 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq, u64 now)
 105 {
 106         SEQ_printf(m, "\ncfs_rq %p\n", cfs_rq);
 107
 108 #define P(x) \
 109         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(cfs_rq->x))
 110
 111         P(fair_clock);
 112         P(exec_clock);
 113         P(wait_runtime);
 114         P(wait_runtime_overruns);
 115         P(wait_runtime_underruns);
 116         P(sleeper_bonus);
 117 #undef P
 118
 119         print_cfs_rq_runtime_sum(m, cpu, cfs_rq);
 120 }
 121
 122 static void print_cpu(struct seq_file *m, int cpu, u64 now)
 123 {
 124         struct rq *rq = &per_cpu(runqueues, cpu);
 125
 126 #ifdef CONFIG_X86
 127         {
 128                 unsigned int freq = cpu_khz ? : 1;
 129
 130                 SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
 131                            cpu, freq / 1000, (freq % 1000));
 132         }
 133 #else
 134         SEQ_printf(m, "\ncpu#%d\n", cpu);
 135 #endif
 136
 137 #define P(x) \
 138         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x))
 139
 140         P(nr_running);
 141         SEQ_printf(m, "  .%-30s: %lu\n", "load",
 142                    rq->ls.load.weight);
 143         P(ls.delta_fair);
 144         P(ls.delta_exec);
 145         P(nr_switches);
 146         P(nr_load_updates);
 147         P(nr_uninterruptible);
 148         SEQ_printf(m, "  .%-30s: %lu\n", "jiffies", jiffies);
 149         P(next_balance);
 150         P(curr->pid);
 151         P(clock);
 152         P(prev_clock_raw);
 153         P(clock_warps);
 154         P(clock_overflows);
 155         P(clock_unstable_events);
 156         P(clock_max_delta);
 157         P(cpu_load[0]);
 158         P(cpu_load[1]);
 159         P(cpu_load[2]);
 160         P(cpu_load[3]);
 161         P(cpu_load[4]);
 162 #undef P
 163
 164         print_cfs_stats(m, cpu, now);
 165
 166         print_rq(m, rq, cpu, now);
 167 }
 168
 169 static int sched_debug_show(struct seq_file *m, void *v)
 170 {
 171         u64 now = ktime_to_ns(ktime_get());
 172         int cpu;
 173
 174         SEQ_printf(m, "Sched Debug Version: v0.04, cfs-v20, %s %.*s\n",
 175                 init_utsname()->release,
 176                 (int)strcspn(init_utsname()->version, " "),
 177                 init_utsname()->version);
 178
 179         SEQ_printf(m, "now at %Lu nsecs\n", (unsigned long long)now);
 180
 181         for_each_online_cpu(cpu)
 182                 print_cpu(m, cpu, now);
 183
 184         SEQ_printf(m, "\n");
 185
 186         return 0;
 187 }
 188
 189 void sysrq_sched_debug_show(void)
 190 {
 191         sched_debug_show(NULL, NULL);
 192 }
 193
 194 static int sched_debug_open(struct inode *inode, struct file *filp)
 195 {
 196         return single_open(filp, sched_debug_show, NULL);
 197 }
 198
 199 static struct file_operations sched_debug_fops = {
 200         .open           = sched_debug_open,
 201         .read           = seq_read,
 202         .llseek         = seq_lseek,
 203         .release        = seq_release,
 204 };
 205
 206 static int __init init_sched_debug_procfs(void)
 207 {
 208         struct proc_dir_entry *pe;
 209
 210         pe = create_proc_entry("sched_debug", 0644, NULL);
 211         if (!pe)
 212                 return -ENOMEM;
 213
 214         pe->proc_fops = &sched_debug_fops;
 215
 216         return 0;
 217 }
 218
 219 __initcall(init_sched_debug_procfs);
 220
 221 void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 222 {
 223         unsigned long flags;
 224         int num_threads = 1;
 225
 226         rcu_read_lock();
 227         if (lock_task_sighand(p, &flags)) {
 228                 num_threads = atomic_read(&p->signal->count);
 229                 unlock_task_sighand(p, &flags);
 230         }
 231         rcu_read_unlock();
 232
 233         SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
 234         SEQ_printf(m, "----------------------------------------------\n");
 235 #define P(F) \
 236         SEQ_printf(m, "%-25s:%20Ld\n", #F, (long long)p->F)
 237
 238         P(se.wait_start);
 239         P(se.wait_start_fair);
 240         P(se.exec_start);
 241         P(se.sleep_start);
 242         P(se.sleep_start_fair);
 243         P(se.block_start);
 244         P(se.sleep_max);
 245         P(se.block_max);
 246         P(se.exec_max);
 247         P(se.wait_max);
 248         P(se.wait_runtime);
 249         P(se.wait_runtime_overruns);
 250         P(se.wait_runtime_underruns);
 251         P(se.sum_wait_runtime);
 252         P(se.sum_exec_runtime);
 253         SEQ_printf(m, "%-25s:%20Ld\n",
 254                    "nr_switches", (long long)(p->nvcsw + p->nivcsw));
 255         P(se.load.weight);
 256         P(policy);
 257         P(prio);
 258 #undef P
 259
 260         {
 261                 u64 t0, t1;
 262
 263                 t0 = sched_clock();
 264                 t1 = sched_clock();
 265                 SEQ_printf(m, "%-25s:%20Ld\n",
 266                            "clock-delta", (long long)(t1-t0));
 267         }
 268 }
 269
 270 void proc_sched_set_task(struct task_struct *p)
 271 {
 272         p->se.sleep_max = p->se.block_max = p->se.exec_max = p->se.wait_max = 0;
 273         p->se.wait_runtime_overruns = p->se.wait_runtime_underruns = 0;
 274         p->se.sum_exec_runtime = 0;
 275 }