5c83545f24
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 /sys/kernel/debug/sleep_time. Cc: Android Kernel Team <kernel-team@android.com> Cc: Colin Cross <ccross@android.com> Cc: Todd Poynor <toddpoynor@google.com> Cc: San Mehat <san@google.com> Cc: Benoit Goby <benoit@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Todd Poynor <toddpoynor@google.com> [zoran.markovic@linaro.org: 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: Zoran Markovic <zoran.markovic@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
73 lines
1.9 KiB
C
73 lines
1.9 KiB
C
/*
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* debugfs file to track time spent in suspend
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*
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* Copyright (c) 2011, Google, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/debugfs.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/seq_file.h>
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#include <linux/time.h>
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static unsigned int sleep_time_bin[32] = {0};
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static int tk_debug_show_sleep_time(struct seq_file *s, void *data)
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{
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unsigned int bin;
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seq_puts(s, " time (secs) count\n");
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seq_puts(s, "------------------------------\n");
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for (bin = 0; bin < 32; bin++) {
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if (sleep_time_bin[bin] == 0)
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continue;
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seq_printf(s, "%10u - %-10u %4u\n",
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bin ? 1 << (bin - 1) : 0, 1 << bin,
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sleep_time_bin[bin]);
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}
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return 0;
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}
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static int tk_debug_sleep_time_open(struct inode *inode, struct file *file)
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{
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return single_open(file, tk_debug_show_sleep_time, NULL);
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}
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static const struct file_operations tk_debug_sleep_time_fops = {
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.open = tk_debug_sleep_time_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int __init tk_debug_sleep_time_init(void)
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{
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struct dentry *d;
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d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
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&tk_debug_sleep_time_fops);
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if (!d) {
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pr_err("Failed to create sleep_time debug file\n");
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return -ENOMEM;
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}
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return 0;
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}
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late_initcall(tk_debug_sleep_time_init);
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void tk_debug_account_sleep_time(struct timespec *t)
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{
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sleep_time_bin[fls(t->tv_sec)]++;
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}
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