kernel/time/timekeeping_debug.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * debugfs file to track time spent in suspend
   4  *
   5  * Copyright (c) 2011, Google, Inc.
   6  */
   7
   8 #include <linux/debugfs.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/suspend.h>
  14 #include <linux/time.h>
  15
  16 #include "timekeeping_internal.h"
  17
  18 #define NUM_BINS 32
  19
  20 static unsigned int sleep_time_bin[NUM_BINS] = {0};
  21
  22 static int tk_debug_sleep_time_show(struct seq_file *s, void *data)
  23 {
  24         unsigned int bin;
  25         seq_puts(s, "      time (secs)        count\n");
  26         seq_puts(s, "------------------------------\n");
  27         for (bin = 0; bin < 32; bin++) {
  28                 if (sleep_time_bin[bin] == 0)
  29                         continue;
  30                 seq_printf(s, "%10u - %-10u %4u\n",
  31                         bin ? 1 << (bin - 1) : 0, 1 << bin,
  32                                 sleep_time_bin[bin]);
  33         }
  34         return 0;
  35 }
  36 DEFINE_SHOW_ATTRIBUTE(tk_debug_sleep_time);
  37
  38 static int __init tk_debug_sleep_time_init(void)
  39 {
  40         debugfs_create_file("sleep_time", 0444, NULL, NULL,
  41                             &tk_debug_sleep_time_fops);
  42         return 0;
  43 }
  44 late_initcall(tk_debug_sleep_time_init);
  45
  46 void tk_debug_account_sleep_time(const struct timespec64 *t)
  47 {
  48         /* Cap bin index so we don't overflow the array */
  49         int bin = min(fls(t->tv_sec), NUM_BINS-1);
  50
  51         sleep_time_bin[bin]++;
  52         pm_deferred_pr_dbg("Timekeeping suspended for %lld.%03lu seconds\n",
  53                            (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC);
  54 }
  55