diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/power/Kconfig | 7 | ||||
| -rw-r--r-- | kernel/power/Makefile | 1 | ||||
| -rw-r--r-- | kernel/power/suspend_time.c | 111 |
3 files changed, 119 insertions, 0 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 3a27c53a0508..fcf5a834c4ec 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -302,3 +302,10 @@ config PM_GENERIC_DOMAINS config PM_GENERIC_DOMAINS_RUNTIME def_bool y depends on PM_RUNTIME && PM_GENERIC_DOMAINS + +config SUSPEND_TIME + bool "Log time spent in suspend" + ---help--- + Prints the time spent in suspend in the kernel log, and + keeps statistics on the time spent in suspend in + /sys/kernel/debug/suspend_time diff --git a/kernel/power/Makefile b/kernel/power/Makefile index 493f19d2a293..9b224e16b191 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -13,5 +13,6 @@ obj-$(CONFIG_USER_WAKELOCK) += userwakelock.o obj-$(CONFIG_EARLYSUSPEND) += earlysuspend.o obj-$(CONFIG_CONSOLE_EARLYSUSPEND) += consoleearlysuspend.o obj-$(CONFIG_FB_EARLYSUSPEND) += fbearlysuspend.o +obj-$(CONFIG_SUSPEND_TIME) += suspend_time.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o diff --git a/kernel/power/suspend_time.c b/kernel/power/suspend_time.c new file mode 100644 index 000000000000..d2a65da9f22c --- /dev/null +++ b/kernel/power/suspend_time.c @@ -0,0 +1,111 @@ +/* + * 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/syscore_ops.h> +#include <linux/time.h> + +static struct timespec suspend_time_before; +static unsigned int time_in_suspend_bins[32]; + +#ifdef CONFIG_DEBUG_FS +static int suspend_time_debug_show(struct seq_file *s, void *data) +{ + int bin; + seq_printf(s, "time (secs) count\n"); + seq_printf(s, "------------------\n"); + for (bin = 0; bin < 32; bin++) { + if (time_in_suspend_bins[bin] == 0) + continue; + seq_printf(s, "%4d - %4d %4u\n", + bin ? 1 << (bin - 1) : 0, 1 << bin, + time_in_suspend_bins[bin]); + } + return 0; +} + +static int suspend_time_debug_open(struct inode *inode, struct file *file) +{ + return single_open(file, suspend_time_debug_show, NULL); +} + +static const struct file_operations suspend_time_debug_fops = { + .open = suspend_time_debug_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init suspend_time_debug_init(void) +{ + struct dentry *d; + + d = debugfs_create_file("suspend_time", 0755, NULL, NULL, + &suspend_time_debug_fops); + if (!d) { + pr_err("Failed to create suspend_time debug file\n"); + return -ENOMEM; + } + + return 0; +} + +late_initcall(suspend_time_debug_init); +#endif + +static int suspend_time_syscore_suspend(void) +{ + read_persistent_clock(&suspend_time_before); + + return 0; +} + +static void suspend_time_syscore_resume(void) +{ + struct timespec after; + + read_persistent_clock(&after); + + after = timespec_sub(after, suspend_time_before); + + time_in_suspend_bins[fls(after.tv_sec)]++; + + pr_info("Suspended for %lu.%03lu seconds\n", after.tv_sec, + after.tv_nsec / NSEC_PER_MSEC); +} + +static struct syscore_ops suspend_time_syscore_ops = { + .suspend = suspend_time_syscore_suspend, + .resume = suspend_time_syscore_resume, +}; + +static int suspend_time_syscore_init(void) +{ + register_syscore_ops(&suspend_time_syscore_ops); + + return 0; +} + +static void suspend_time_syscore_exit(void) +{ + unregister_syscore_ops(&suspend_time_syscore_ops); +} +module_init(suspend_time_syscore_init); +module_exit(suspend_time_syscore_exit); |