Commit 5c83545f authored by Colin Cross's avatar Colin Cross Committed by John Stultz

power: Add option to log time spent in suspend

Below is a patch from android kernel that maintains a histogram of
suspend times. Please review and provide feedback.

Statistices on the time spent in suspend are kept in

Cc: Android Kernel Team <>
Cc: Colin Cross <>
Cc: Todd Poynor <>
Cc: San Mehat <>
Cc: Benoit Goby <>
Cc: John Stultz <>
Cc: Thomas Gleixner <>
Signed-off-by: default avatarColin Cross <>
Signed-off-by: default avatarTodd Poynor <>
[ Re-formatted suspend time table to better
fit expected values. Moved accounting of suspend time into timekeeping
core. Removed CONFIG_SUSPEND_TIME flag and made the feature conditional
on CONFIG_DEBUG_FS. Changed the file name to sleep_time to better fit
terminology in timekeeping core. Changed seq_printf to seq_puts. Tweaked
commit message]
Signed-off-by: default avatarZoran Markovic <>
Signed-off-by: default avatarJohn Stultz <>
parent 11ffa9d6
......@@ -7,3 +7,4 @@ obj-$(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) += tick-broadcast.o
obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o
obj-$(CONFIG_TICK_ONESHOT) += tick-sched.o
obj-$(CONFIG_TIMER_STATS) += timer_stats.o
obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o
......@@ -25,6 +25,7 @@
#include "tick-internal.h"
#include "ntp_internal.h"
#include "timekeeping_internal.h"
static struct timekeeper timekeeper;
static DEFINE_RAW_SPINLOCK(timekeeper_lock);
......@@ -851,6 +852,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
tk_xtime_add(tk, delta);
tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
* debugfs file to track time spent in suspend
* Copyright (c) 2011, Google, Inc.
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/seq_file.h>
#include <linux/time.h>
static unsigned int sleep_time_bin[32] = {0};
static int tk_debug_show_sleep_time(struct seq_file *s, void *data)
unsigned int bin;
seq_puts(s, " time (secs) count\n");
seq_puts(s, "------------------------------\n");
for (bin = 0; bin < 32; bin++) {
if (sleep_time_bin[bin] == 0)
seq_printf(s, "%10u - %-10u %4u\n",
bin ? 1 << (bin - 1) : 0, 1 << bin,
return 0;
static int tk_debug_sleep_time_open(struct inode *inode, struct file *file)
return single_open(file, tk_debug_show_sleep_time, NULL);
static const struct file_operations tk_debug_sleep_time_fops = {
.open = tk_debug_sleep_time_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
static int __init tk_debug_sleep_time_init(void)
struct dentry *d;
d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
if (!d) {
pr_err("Failed to create sleep_time debug file\n");
return -ENOMEM;
return 0;
void tk_debug_account_sleep_time(struct timespec *t)
* timekeeping debug functions
#include <linux/time.h>
extern void tk_debug_account_sleep_time(struct timespec *t);
#define tk_debug_account_sleep_time(x)
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment