LXR linux/kernel/time/timekeeping

   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
  20static unsigned int sleep_time_bin[NUM_BINS] = {0};
  21
  22static 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}
  36DEFINE_SHOW_ATTRIBUTE(tk_debug_sleep_time);
  37
  38static 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}
  44late_initcall(tk_debug_sleep_time_init);
  45
  46void 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
  56