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                 p->comm, p->pid,
  41                 (long long)p->se.fair_key,
  42                 (long long)(p->se.fair_key - rq->cfs.fair_clock),
  43                 (long long)p->se.wait_runtime,
  44                 (long long)(p->nvcsw + p->nivcsw),
  45                 p->prio);
  46 #ifdef CONFIG_SCHEDSTATS
  47         SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld\n",
  48                 (long long)p->se.sum_exec_runtime,
  49                 (long long)p->se.sum_wait_runtime,
  50                 (long long)p->se.sum_sleep_runtime,
  51                 (long long)p->se.wait_runtime_overruns,
  52                 (long long)p->se.wait_runtime_underruns);
  53 #else
  54         SEQ_printf(m, "%15Ld %15Ld %15Ld %15Ld %15Ld\n",
  55                 0LL, 0LL, 0LL, 0LL, 0LL);
  56 #endif
  57 }
  58
  59 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu, u64 now)
  60 {
  61         struct task_struct *g, *p;
  62
  63         SEQ_printf(m,
  64         "\nrunnable tasks:\n"
  65         "            task   PID        tree-key         delta       waiting"
  66         "  switches  prio"
  67         "        sum-exec        sum-wait       sum-sleep"
  68         "    wait-overrun   wait-underrun\n"
  69         "------------------------------------------------------------------"
  70         "----------------"
  71         "------------------------------------------------"
  72         "--------------------------------\n");
  73
  74         read_lock_irq(&tasklist_lock);
  75
  76         do_each_thread(g, p) {
  77                 if (!p->se.on_rq || task_cpu(p) != rq_cpu)
  78                         continue;
  79
  80                 print_task(m, rq, p, now);
  81         } while_each_thread(g, p);
  82
  83         read_unlock_irq(&tasklist_lock);
  84 }
  85
  86 static void
  87 print_cfs_rq_runtime_sum(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
  88 {
  89         s64 wait_runtime_rq_sum = 0;
  90         struct task_struct *p;
  91         struct rb_node *curr;
  92         unsigned long flags;
  93         struct rq *rq = &per_cpu(runqueues, cpu);
  94
  95         spin_lock_irqsave(&rq->lock, flags);
  96         curr = first_fair(cfs_rq);
  97         while (curr) {
  98                 p = rb_entry(curr, struct task_struct, se.run_node);
  99                 wait_runtime_rq_sum += p->se.wait_runtime;
 100
 101                 curr = rb_next(curr);
 102         }
 103         spin_unlock_irqrestore(&rq->lock, flags);
 104
 105         SEQ_printf(m, "  .%-30s: %Ld\n", "wait_runtime_rq_sum",
 106                 (long long)wait_runtime_rq_sum);
 107 }
 108
 109 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq, u64 now)
 110 {
 111         SEQ_printf(m, "\ncfs_rq %p\n", cfs_rq);
 112
 113 #define P(x) \
 114         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(cfs_rq->x))
 115
 116         P(fair_clock);
 117         P(exec_clock);
 118         P(wait_runtime);
 119         P(wait_runtime_overruns);
 120         P(wait_runtime_underruns);
 121         P(sleeper_bonus);
 122 #undef P
 123
 124         print_cfs_rq_runtime_sum(m, cpu, cfs_rq);
 125 }
 126
 127 static void print_cpu(struct seq_file *m, int cpu, u64 now)
 128 {
 129         struct rq *rq = &per_cpu(runqueues, cpu);
 130
 131 #ifdef CONFIG_X86
 132         {
 133                 unsigned int freq = cpu_khz ? : 1;
 134
 135                 SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
 136                            cpu, freq / 1000, (freq % 1000));
 137         }
 138 #else
 139         SEQ_printf(m, "\ncpu#%d\n", cpu);
 140 #endif
 141
 142 #define P(x) \
 143         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x))
 144
 145         P(nr_running);
 146         SEQ_printf(m, "  .%-30s: %lu\n", "load",
 147                    rq->ls.load.weight);
 148         P(ls.delta_fair);
 149         P(ls.delta_exec);
 150         P(nr_switches);
 151         P(nr_load_updates);
 152         P(nr_uninterruptible);
 153         SEQ_printf(m, "  .%-30s: %lu\n", "jiffies", jiffies);
 154         P(next_balance);
 155         P(curr->pid);
 156         P(clock);
 157         P(prev_clock_raw);
 158         P(clock_warps);
 159         P(clock_overflows);
 160         P(clock_unstable_events);
 161         P(clock_max_delta);
 162         P(cpu_load[0]);
 163         P(cpu_load[1]);
 164         P(cpu_load[2]);
 165         P(cpu_load[3]);
 166         P(cpu_load[4]);
 167 #undef P
 168
 169         print_cfs_stats(m, cpu, now);
 170
 171         print_rq(m, rq, cpu, now);
 172 }
 173
 174 static int sched_debug_show(struct seq_file *m, void *v)
 175 {
 176         u64 now = ktime_to_ns(ktime_get());
 177         int cpu;
 178
 179         SEQ_printf(m, "Sched Debug Version: v0.05-v20, %s %.*s\n",
 180                 init_utsname()->release,
 181                 (int)strcspn(init_utsname()->version, " "),
 182                 init_utsname()->version);
 183
 184         SEQ_printf(m, "now at %Lu nsecs\n", (unsigned long long)now);
 185
 186         for_each_online_cpu(cpu)
 187                 print_cpu(m, cpu, now);
 188
 189         SEQ_printf(m, "\n");
 190
 191         return 0;
 192 }
 193
 194 static void sysrq_sched_debug_show(void)
 195 {
 196         sched_debug_show(NULL, NULL);
 197 }
 198
 199 static int sched_debug_open(struct inode *inode, struct file *filp)
 200 {
 201         return single_open(filp, sched_debug_show, NULL);
 202 }
 203
 204 static struct file_operations sched_debug_fops = {
 205         .open           = sched_debug_open,
 206         .read           = seq_read,
 207         .llseek         = seq_lseek,
 208         .release        = single_release,
 209 };
 210
 211 static int __init init_sched_debug_procfs(void)
 212 {
 213         struct proc_dir_entry *pe;
 214
 215         pe = create_proc_entry("sched_debug", 0644, NULL);
 216         if (!pe)
 217                 return -ENOMEM;
 218
 219         pe->proc_fops = &sched_debug_fops;
 220
 221         return 0;
 222 }
 223
 224 __initcall(init_sched_debug_procfs);
 225
 226 void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 227 {
 228         unsigned long flags;
 229         int num_threads = 1;
 230
 231         rcu_read_lock();
 232         if (lock_task_sighand(p, &flags)) {
 233                 num_threads = atomic_read(&p->signal->count);
 234                 unlock_task_sighand(p, &flags);
 235         }
 236         rcu_read_unlock();
 237
 238         SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
 239         SEQ_printf(m, "----------------------------------------------\n");
 240 #define P(F) \
 241         SEQ_printf(m, "%-25s:%20Ld\n", #F, (long long)p->F)
 242
 243         P(se.wait_runtime);
 244         P(se.wait_start_fair);
 245         P(se.exec_start);
 246         P(se.sleep_start_fair);
 247         P(se.sum_exec_runtime);
 248
 249 #ifdef CONFIG_SCHEDSTATS
 250         P(se.wait_start);
 251         P(se.sleep_start);
 252         P(se.block_start);
 253         P(se.sleep_max);
 254         P(se.block_max);
 255         P(se.exec_max);
 256         P(se.wait_max);
 257         P(se.wait_runtime_overruns);
 258         P(se.wait_runtime_underruns);
 259         P(se.sum_wait_runtime);
 260 #endif
 261         SEQ_printf(m, "%-25s:%20Ld\n",
 262                    "nr_switches", (long long)(p->nvcsw + p->nivcsw));
 263         P(se.load.weight);
 264         P(policy);
 265         P(prio);
 266 #undef P
 267
 268         {
 269                 u64 t0, t1;
 270
 271                 t0 = sched_clock();
 272                 t1 = sched_clock();
 273                 SEQ_printf(m, "%-25s:%20Ld\n",
 274                            "clock-delta", (long long)(t1-t0));
 275         }
 276 }
 277
 278 void proc_sched_set_task(struct task_struct *p)
 279 {
 280 #ifdef CONFIG_SCHEDSTATS
 281         p->se.sleep_max = p->se.block_max = p->se.exec_max = p->se.wait_max = 0;
 282         p->se.wait_runtime_overruns = p->se.wait_runtime_underruns = 0;
 283 #endif
 284         p->se.sum_exec_runtime = 0;
 285 }