xref: /linux/kernel/time/timekeeping_debug.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * debugfs file to track time spent in suspend
3  *
4  * Copyright (c) 2011, Google, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  */
16 
17 #include <linux/debugfs.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/seq_file.h>
22 #include <linux/time.h>
23 
24 #include "timekeeping_internal.h"
25 
26 static unsigned int sleep_time_bin[32] = {0};
27 
28 static int tk_debug_show_sleep_time(struct seq_file *s, void *data)
29 {
30 	unsigned int bin;
31 	seq_puts(s, "      time (secs)        count\n");
32 	seq_puts(s, "------------------------------\n");
33 	for (bin = 0; bin < 32; bin++) {
34 		if (sleep_time_bin[bin] == 0)
35 			continue;
36 		seq_printf(s, "%10u - %-10u %4u\n",
37 			bin ? 1 << (bin - 1) : 0, 1 << bin,
38 				sleep_time_bin[bin]);
39 	}
40 	return 0;
41 }
42 
43 static int tk_debug_sleep_time_open(struct inode *inode, struct file *file)
44 {
45 	return single_open(file, tk_debug_show_sleep_time, NULL);
46 }
47 
48 static const struct file_operations tk_debug_sleep_time_fops = {
49 	.open		= tk_debug_sleep_time_open,
50 	.read		= seq_read,
51 	.llseek		= seq_lseek,
52 	.release	= single_release,
53 };
54 
55 static int __init tk_debug_sleep_time_init(void)
56 {
57 	struct dentry *d;
58 
59 	d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
60 		&tk_debug_sleep_time_fops);
61 	if (!d) {
62 		pr_err("Failed to create sleep_time debug file\n");
63 		return -ENOMEM;
64 	}
65 
66 	return 0;
67 }
68 late_initcall(tk_debug_sleep_time_init);
69 
70 void tk_debug_account_sleep_time(struct timespec64 *t)
71 {
72 	sleep_time_bin[fls(t->tv_sec)]++;
73 }
74 
75