Subject: [PATCH] Boottime: A tool for automatic measurement of kernel/bootloader boot time

From: [email-masked] (Dan Murphy)
Date: Fri, 12 Oct 2012 08:35:36 -0500

On a note on testing.

OK this at least compiles on my system with 3.4.

The weird thing is that I get the same exact kernel boot time for two 
different machines.
When I cat the summary for the kernel.
I am not profiling the bootloader time here as it is neglible so no ATAG 
argument.

kernel: 3221288 msecs
total: 3221288 msecs
kernel: cpu0 system: 0% idle: 0% iowait: 0% irq: 0% cpu1 system: 0% 
idle: 0% iowait: 0% irq: 0%

And I get no output from any of the bootgraph entries.

Dan

On 10/12/2012 04:51 AM, Lee Jones wrote:
> Okay, please disgard the last patch. Lots of fixups since.
>
> Author: Lee Jones <[email-masked]>
> Date:   Wed Jun 30 14:00:40 2010 +0200
>
>      Boottime: A tool for automatic measurement of kernel/bootloader boot time
>      
>      The overhead is very low and the results will be found under
>      sysfs/bootime, as well as detailed results in debugfs under
>      boottime/. The bootgraph* files are compatible with
>      scripts/bootgraph.pl. The reason for this patch is to provide
>      data (sysfs/boottime) suitable for automatic test-cases as
>      well as help for developers to reduce the boot time (debugfs).
>      
>      Based heavily on the original driver by Jonas Aaberg.
>      
>      Cc: Russell King <[email-masked]>
>      Cc: Will Deacon <[email-masked]>
>      Signed-off-by: Jonas Aaberg <[email-masked]>
>      Signed-off-by: Mian Yousaf Kaukab <[email-masked]>
>      Signed-off-by: Lee Jones <[email-masked]>
>      Reviewed-by: Srinidhi KASAGAR <[email-masked]>
>      Tested-by: Mian Yousaf KAUKAB <[email-masked]>
>
> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
> index e8a4e58..8522356 100644
> --- a/arch/arm/common/Makefile
> +++ b/arch/arm/common/Makefile
> @@ -13,3 +13,4 @@ obj-$(CONFIG_SHARP_PARAM)	+= sharpsl_param.o
>   obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
>   obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
>   obj-$(CONFIG_ARM_TIMER_SP804)	+= timer-sp.o
> +obj-$(CONFIG_BOOTTIME)		+= boottime.o
> diff --git a/arch/arm/common/boottime.c b/arch/arm/common/boottime.c
> new file mode 100644
> index 0000000..73e9e04
> --- /dev/null
> +++ b/arch/arm/common/boottime.c
> @@ -0,0 +1,46 @@
> +/*
> + * Copyright (C) ST-Ericsson SA 2009-2010
> + *
> + * Author: Jonas Aaberg <[email-masked]> for ST-Ericsson
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + *
> + * Store boot times measured during for example u-boot startup.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/boottime.h>
> +#include <linux/string.h>
> +#include <asm/setup.h>
> +
> +static u32 bootloader_idle;
> +static u32 bootloader_total;
> +
> +static int __init boottime_parse_tag(const struct tag *tag)
> +{
> +	int i;
> +	char buff[BOOTTIME_MAX_NAME_LEN];
> +
> +	bootloader_idle = tag->u.boottime.idle;
> +	bootloader_total = tag->u.boottime.total;
> +
> +	for (i = 0; i < tag->u.boottime.num; i++) {
> +		snprintf(buff, BOOTTIME_MAX_NAME_LEN, "%s+0x0/0x0",
> +			 tag->u.boottime.entry[i].name);
> +		buff[BOOTTIME_MAX_NAME_LEN - 1] = '\0';
> +		boottime_mark_wtime(buff, tag->u.boottime.entry[i].time);
> +	}
> +
> +	return 0;
> +}
> +
> +__tagtable(ATAG_BOOTTIME,  boottime_parse_tag);
> +
> +int boottime_bootloader_idle(void)
> +{
> +	if (bootloader_total == 0)
> +		return 0;
> +
> +	return (int) ((bootloader_idle) / (bootloader_total / 100));
> +}
> diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h
> index 24d284a..e8da062 100644
> --- a/arch/arm/include/asm/setup.h
> +++ b/arch/arm/include/asm/setup.h
> @@ -143,6 +143,23 @@ struct tag_memclk {
>   	__u32 fmemclk;
>   };
>   
> +/* for automatic boot timing testcases */
> +#define ATAG_BOOTTIME  0x41000403
> +#define BOOTTIME_MAX_NAME_LEN 64
> +#define BOOTTIME_MAX 10
> +
> +struct boottime_entry {
> +	u32 time; /* in us */
> +	u8  name[BOOTTIME_MAX_NAME_LEN];
> +};
> +
> +struct tag_boottime {
> +	struct boottime_entry entry[BOOTTIME_MAX];
> +	u32 idle;  /* in us */
> +	u32 total; /* in us */
> +	u8 num;
> +};
> +
>   struct tag {
>   	struct tag_header hdr;
>   	union {
> @@ -165,6 +182,10 @@ struct tag {
>   		 * DC21285 specific
>   		 */
>   		struct tag_memclk	memclk;
> +		/*
> +		 * Boot time
> +		 */
> +		struct tag_boottime	boottime;
>   	} u;
>   };
>   
> diff --git a/include/linux/boottime.h b/include/linux/boottime.h
> new file mode 100644
> index 0000000..d330ecd
> --- /dev/null
> +++ b/include/linux/boottime.h
> @@ -0,0 +1,89 @@
> +/*
> + * Copyright (C) ST-Ericsson SA 2009-2010
> + *
> + * Author: Jonas Aaberg <[email-masked]> for ST-Ericsson
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + *
> + * boottime is a tool for collecting start-up timing
> + * information and can together with boot loader support
> + * display a total system start-up time.
> + *
> + */
> +
> +#ifndef LINUX_BOOTTIME_H
> +#define LINUX_BOOTTIME_H
> +
> +#ifdef CONFIG_BOOTTIME
> +#include <linux/kernel.h>
> +
> +/**
> + * struct boottime_timer - Callbacks for generic timer.
> + * @init: Function to call at boottime initialization
> + * @get_time: Returns the number of us since start-up
> + *            Preferable this is based upon a free running timer.
> + *            This is the only required entry.
> + * @finalize: Called before init is executed and boottime is done.
> + */
> +struct boottime_timer {
> +	int (*init)(void);
> +	unsigned long (*get_time)(void);
> +	void (*finalize)(void);
> +};
> +
> +/**
> + * boottime_mark_wtime()
> + * Add a sample point with a given time. Useful for adding data collected
> + * by for example a boot loader.
> + * @name: The name of the sample point
> + * @time: The time in us when this point was reached
> + */
> +void __init boottime_mark_wtime(char *name, unsigned long time);
> +
> +/**
> + * boottime_mark()
> + * Add a sample point with the current time.
> + * @name: The name of this sample point
> + */
> +void boottime_mark(char *name);
> +
> +/**
> + * boottime_mark_symbolic()
> + * Add a sample point where the name is a symbolic function
> + * and %pF is needed to get the correct function name.
> + * @name: function name.
> + */
> +void __init boottime_mark_symbolic(void *name);
> +
> +/**
> + * boottime_activate()
> + * Activates boottime and register callbacks.
> + * @bt: struct with callbacks.
> + */
> +void __ref boottime_activate(struct boottime_timer *bt);
> +
> +/**
> + * boottime_deactivate()
> + * This function is called when the kernel boot is done.
> + * (before "free init memory" is called)
> + */
> +void boottime_deactivate(void);
> +
> +/**
> + * boottime_system_up()
> + * A function is called when the basics of the kernel
> + * is up and running.
> + */
> +void __init boottime_system_up(void);
> +
> +#else
> +
> +#define boottime_mark_wtime(name, time)
> +#define boottime_mark(name)
> +#define boottime_mark_symbolic(name)
> +#define boottime_activate(bt)
> +#define boottime_deactivate()
> +#define boottime_system_up()
> +#endif
> +
> +#endif /* LINUX_BOOTTIME_H */
> diff --git a/init/Kconfig b/init/Kconfig
> index 4c93533..d0df8ff 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1464,6 +1464,15 @@ config PROFILING
>   	  Say Y here to enable the extended profiling support mechanisms used
>   	  by profilers such as OProfile.
>   
> +config BOOTTIME
> +	bool "Boot time measurements"
> +	default n
> +	help
> +		Adds sysfs entries (boottime/) with start-up timing information.
> +		If CONFIG_DEBUG_FS is enabled, detailed information about the
> +		boot time, including system load during boot can be extracted.
> +		This information can be visualised with help of the bootgraph script.
> +
>   #
>   # Place an empty function call at each tracepoint site. Can be
>   # dynamically changed for a probe function.
> diff --git a/init/Makefile b/init/Makefile
> index 7bc47ee..356d529 100644
> --- a/init/Makefile
> +++ b/init/Makefile
> @@ -9,6 +9,7 @@ else
>   obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
>   endif
>   obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
> +obj-$(CONFIG_BOOTTIME)		      += boottime.o
>   
>   ifneq ($(CONFIG_ARCH_INIT_TASK),y)
>   obj-y                          += init_task.o
> diff --git a/init/boottime.c b/init/boottime.c
> new file mode 100644
> index 0000000..793c184
> --- /dev/null
> +++ b/init/boottime.c
> @@ -0,0 +1,475 @@
> +/*
> + * Copyright (C) ST-Ericsson SA 2009-2010
> + *
> + * Author: Jonas Aaberg <[email-masked]> for ST-Ericsson
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + *
> + * boottime is a tool for collecting start-up timing
> + * information and can together with boot loader support
> + * display a total system start-up time.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/list.h>
> +#include <linux/seq_file.h>
> +#include <linux/debugfs.h>
> +#include <linux/spinlock.h>
> +#include <linux/boottime.h>
> +#include <linux/kernel_stat.h>
> +#include <linux/kobject.h>
> +#include <linux/device.h>
> +#include <linux/sysfs.h>
> +#include <linux/slab.h>
> +
> +/*
> + * BOOTTIME_MAX_NAME_LEN is defined in arch/arm/include/asm/setup.h to 64.
> + * No crisis if they don't match.
> + */
> +#ifndef BOOTTIME_MAX_NAME_LEN
> +#define BOOTTIME_MAX_NAME_LEN 64
> +#endif
> +
> +/*
> + * We have a few static entries, since it is good to have measure points
> + * before the system is up and running properly
> + */
> +#define NUM_STATIC_BOOTTIME_ENTRIES 32
> +
> +struct boottime_list {
> +	struct list_head list;
> +	char name[BOOTTIME_MAX_NAME_LEN];
> +	/* Time in us since power on, possible including boot loader. */
> +	unsigned long time;
> +	bool cpu_load;
> +	struct kernel_cpustat cpu_usage[NR_CPUS];
> +};
> +
> +enum boottime_filter_type {
> +	BOOTTIME_FILTER_OUT_ZERO,
> +	BOOTTIME_FILTER_OUT_LESS_100,
> +	BOOTTIME_FILTER_NOTHING,
> +};
> +
> +enum boottime_symbolic_print {
> +	BOOTTIME_SYMBOLIC_PRINT,
> +	BOOTTIME_NORMAL_PRINT,
> +};
> +
> +enum boottime_cpu_load {
> +	BOOTTIME_CPU_LOAD,
> +	BOOTTIME_NO_CPU_LOAD,
> +};
> +
> +static LIST_HEAD(boottime_list);
> +static DEFINE_SPINLOCK(boottime_list_lock);
> +static struct boottime_timer boottime_timer;
> +static int num_const_boottime_list;
> +static struct boottime_list const_boottime_list[NUM_STATIC_BOOTTIME_ENTRIES];
> +static unsigned long time_kernel_done;
> +static unsigned long time_bootloader_done;
> +static bool system_up;
> +static bool boottime_done;
> +
> +int __attribute__((weak)) boottime_arch_startup(void)
> +{
> +	return 0;
> +}
> +
> +int __attribute__((weak)) boottime_bootloader_idle(void)
> +{
> +	return 0;
> +}
> +
> +static void boottime_mark_core(char *name,
> +				      unsigned long time,
> +				      enum boottime_symbolic_print symbolic,
> +				      enum boottime_cpu_load cpu_load)
> +{
> +	struct boottime_list *b;
> +	unsigned long flags = 0;
> +	int i;
> +
> +	if (system_up) {
> +		b = kmalloc(sizeof(struct boottime_list), GFP_KERNEL);
> +		if (!b) {
> +			printk(KERN_ERR
> +			       "boottime: failed to allocate memory!\n");
> +			return;
> +		}
> +
> +	} else {
> +		if (num_const_boottime_list < NUM_STATIC_BOOTTIME_ENTRIES) {
> +			b = &const_boottime_list[num_const_boottime_list];
> +			num_const_boottime_list++;
> +		} else {
> +			printk(KERN_ERR
> +			       "boottime: too many early measure points!\n");
> +			return;
> +		}
> +	}
> +
> +	INIT_LIST_HEAD(&b->list);
> +
> +	if (symbolic == BOOTTIME_SYMBOLIC_PRINT)
> +		snprintf(b->name, BOOTTIME_MAX_NAME_LEN, "%pF", name);
> +	else
> +		strncpy(b->name, name, BOOTTIME_MAX_NAME_LEN);
> +
> +	b->name[BOOTTIME_MAX_NAME_LEN - 1] = '\0';
> +	b->time = time;
> +	b->cpu_load = cpu_load;
> +
> +	if (cpu_load == BOOTTIME_CPU_LOAD && system_up)
> +		for_each_possible_cpu(i) {
> +			b->cpu_usage[i].cpustat[CPUTIME_SYSTEM] =
> +				kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
> +			b->cpu_usage[i].cpustat[CPUTIME_IDLE] =
> +				kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
> +			b->cpu_usage[i].cpustat[CPUTIME_IOWAIT] =
> +				kcpustat_cpu(i).cpustat[CPUTIME_IOWAIT];
> +			b->cpu_usage[i].cpustat[CPUTIME_IRQ] =
> +				kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
> +			/*
> +			 * TODO: Make sure that user, nice, softirq, steal
> +			 * and guest are not used during boot
> +			 */
> +		}
> +	else
> +		b->cpu_load = BOOTTIME_NO_CPU_LOAD;
> +
> +	if (system_up) {
> +		spin_lock_irqsave(&boottime_list_lock, flags);
> +		list_add(&b->list, &boottime_list);
> +		spin_unlock_irqrestore(&boottime_list_lock, flags);
> +	} else {
> +		list_add(&b->list, &boottime_list);
> +	}
> +}
> +
> +void __init boottime_mark_wtime(char *name, unsigned long time)
> +{
> +	boottime_mark_core(name, time,
> +			   BOOTTIME_NORMAL_PRINT,
> +			   BOOTTIME_NO_CPU_LOAD);
> +}
> +
> +void __ref boottime_mark_symbolic(void *name)
> +{
> +
> +	if (boottime_done)
> +		return;
> +
> +	if (boottime_timer.get_time)
> +		boottime_mark_core((char *) name,
> +				   boottime_timer.get_time(),
> +				   BOOTTIME_SYMBOLIC_PRINT,
> +				   BOOTTIME_CPU_LOAD);
> +}
> +
> +void boottime_mark(char *name)
> +{
> +	if (boottime_timer.get_time)
> +		boottime_mark_core(name,
> +				   boottime_timer.get_time(),
> +				   BOOTTIME_NORMAL_PRINT,
> +				   BOOTTIME_CPU_LOAD);
> +}
> +
> +void __init boottime_activate(struct boottime_timer *bt)
> +{
> +	struct boottime_list *b;
> +	int res = 0;
> +	unsigned long flags;
> +
> +	if (bt == NULL) {
> +		printk(KERN_ERR
> +		       "boottime: error: bad configured\n");
> +		return;
> +	}
> +
> +	if (bt->get_time == NULL) {
> +		printk(KERN_ERR
> +		       "boottime: error: you must provide a get_time() function\n");
> +		return;
> +	}
> +	memcpy(&boottime_timer, bt, sizeof(struct boottime_timer));
> +
> +	if (boottime_timer.init)
> +		res = boottime_timer.init();
> +
> +	if (res) {
> +		printk(KERN_ERR "boottime: initialization failed\n");
> +		return;
> +	}
> +
> +	if (boottime_arch_startup())
> +		printk(KERN_ERR
> +		       "boottime: arch specfic initialization failed\n");
> +
> +	spin_lock_irqsave(&boottime_list_lock, flags);
> +
> +	if (!list_empty(&boottime_list)) {
> +
> +		b = list_first_entry(&boottime_list, struct boottime_list,
> +				     list);
> +		if (b)
> +			time_bootloader_done = b->time;
> +	}
> +
> +	spin_unlock_irqrestore(&boottime_list_lock, flags);
> +}
> +
> +void __init boottime_system_up(void)
> +{
> +	system_up = true;
> +}
> +
> +void boottime_deactivate(void)
> +{
> +	struct boottime_list *b;
> +	unsigned long flags;
> +
> +	boottime_mark("execute_init+0x0/0x0");
> +
> +	boottime_done = true;
> +
> +	spin_lock_irqsave(&boottime_list_lock, flags);
> +	b = list_first_entry(&boottime_list, struct boottime_list, list);
> +	spin_unlock_irqrestore(&boottime_list_lock, flags);
> +
> +	time_kernel_done = b->time;
> +
> +	if (boottime_timer.finalize)
> +		boottime_timer.finalize();
> +}
> +
> +#ifdef CONFIG_DEBUG_FS
> +static void boottime_debugfs_load(struct seq_file *s,
> +				  struct boottime_list *b,
> +				  struct boottime_list *p)
> +{
> +	int i;
> +	unsigned long total_p, total_b;
> +	unsigned long system_total, idle_total, irq_total, iowait_total;
> +	unsigned long system_load, idle_load, irq_load, iowait_load;
> +
> +	for_each_possible_cpu(i) {
> +		total_b = (b->cpu_usage[i].cpustat[CPUTIME_SYSTEM] +
> +			   b->cpu_usage[i].cpustat[CPUTIME_IDLE] +
> +			   b->cpu_usage[i].cpustat[CPUTIME_IOWAIT] +
> +			   b->cpu_usage[i].cpustat[CPUTIME_IRQ]);
> +
> +		total_p = (p->cpu_usage[i].cpustat[CPUTIME_SYSTEM] +
> +			   p->cpu_usage[i].cpustat[CPUTIME_IDLE] +
> +			   p->cpu_usage[i].cpustat[CPUTIME_IOWAIT] +
> +			   p->cpu_usage[i].cpustat[CPUTIME_IRQ]);
> +
> +		if (total_b == total_p)
> +			continue;
> +
> +		system_total = b->cpu_usage[i].cpustat[CPUTIME_SYSTEM]
> +			- p->cpu_usage[i].cpustat[CPUTIME_SYSTEM];
> +		idle_total = b->cpu_usage[i].cpustat[CPUTIME_IDLE]
> +			- p->cpu_usage[i].cpustat[CPUTIME_IDLE];
> +		irq_total = b->cpu_usage[i].cpustat[CPUTIME_IRQ]
> +			- p->cpu_usage[i].cpustat[CPUTIME_IRQ];
> +		iowait_total = b->cpu_usage[i].cpustat[CPUTIME_IOWAIT]
> +			- p->cpu_usage[i].cpustat[CPUTIME_IOWAIT];
> +
> +		system_load = (100 * system_total / (total_b - total_p));
> +		idle_load = (100 * idle_total / (total_b - total_p));
> +		irq_load = (100 * irq_total / (total_b - total_p));
> +		iowait_load = (100 * iowait_total / (total_b - total_p));
> +
> +		seq_printf(s,
> +			   " cpu%d system: %lu%% idle: %lu%% iowait: %lu%% irq: %lu%%",
> +			   i,
> +			   system_load,
> +			   idle_load,
> +			   iowait_load,
> +			   irq_load);
> +	}
> +	seq_printf(s, "\n");
> +}
> +
> +static void boottime_debugfs_print(struct seq_file *s,
> +				   struct boottime_list *b,
> +				   struct boottime_list *p)
> +{
> +	seq_printf(s, "[%5lu.%06lu] calling  %s\n",
> +		   p->time / 1000000,
> +		   (p->time  % 1000000),
> +		   p->name);
> +	seq_printf(s, "[%5lu.%06lu] initcall %s returned 0 after %ld msecs.",
> +		   b->time / 1000000,
> +		   (b->time  % 1000000),
> +		   p->name, (b->time - p->time) / 1000);
> +
> +	if (p->cpu_load == BOOTTIME_NO_CPU_LOAD ||
> +	    b->cpu_load == BOOTTIME_NO_CPU_LOAD) {
> +		seq_printf(s, "\n");
> +		return;
> +	}
> +
> +	boottime_debugfs_load(s, b, p);
> +}
> +
> +static int boottime_debugfs_bootgraph_show(struct seq_file *s, void *iter)
> +{
> +	struct boottime_list *b, *p = NULL, *old_p = NULL;
> +	enum boottime_filter_type filter = (int)s->private;
> +
> +	list_for_each_entry_reverse(b, &boottime_list, list) {
> +		if (p) {
> +			if (!(filter == BOOTTIME_FILTER_OUT_ZERO &&
> +			     (b->time - p->time) / 1000 == 0)
> +			   && !(filter == BOOTTIME_FILTER_OUT_LESS_100 &&
> +				(b->time - p->time) < 100 * 1000))
> +				boottime_debugfs_print(s, b, p);
> +			old_p = p;
> +		}
> +		p = b;
> +	}
> +
> +	if (filter == BOOTTIME_FILTER_NOTHING && p)
> +		boottime_debugfs_print(s, p, p);
> +
> +	if (p)
> +		seq_printf(s, "[%5lu.%06lu] Freeing init memory: 0K\n",
> +			   p->time / 1000000, p->time  % 1000000);
> +	return 0;
> +}
> +
> +static int boottime_debugfs_summary_show(struct seq_file *s, void *data)
> +{
> +	struct boottime_list *b, b_zero;
> +
> +	if (time_bootloader_done)
> +		seq_printf(s, "bootloader: %ld msecs\n",
> +			   time_bootloader_done / 1000);
> +
> +	seq_printf(s, "kernel: %ld msecs\ntotal: %ld msecs\n",
> +		   (time_kernel_done - time_bootloader_done) / 1000,
> +		   time_kernel_done / 1000);
> +	seq_printf(s, "kernel:");
> +	b = list_first_entry(&boottime_list,
> +			     struct boottime_list, list);
> +	memset(&b_zero, 0, sizeof(struct boottime_list));
> +	boottime_debugfs_load(s, b, &b_zero);
> +
> +	if (time_bootloader_done)
> +		seq_printf(s,
> +			   "bootloader: cpu0 system: %d%% idle: %d%% iowait: 0%% irq: 0%%\n",
> +			   100 - boottime_bootloader_idle(),
> +			   boottime_bootloader_idle());
> +	return 0;
> +}
> +
> +static int boottime_debugfs_bootgraph_open(struct inode *inode,
> +					   struct file *file)
> +{
> +	return single_open(file,
> +			   boottime_debugfs_bootgraph_show,
> +			   inode->i_private);
> +}
> +
> +static int boottime_debugfs_summary_open(struct inode *inode,
> +					 struct file *file)
> +{
> +	return single_open(file,
> +			   boottime_debugfs_summary_show,
> +			   inode->i_private);
> +}
> +
> +static const struct file_operations boottime_debugfs_bootgraph_operations = {
> +	.open		= boottime_debugfs_bootgraph_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= single_release,
> +};
> +
> +static const struct file_operations boottime_debugfs_summary_operations = {
> +	.open		= boottime_debugfs_summary_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= single_release,
> +};
> +
> +void boottime_debugfs_init(void)
> +{
> +	struct dentry *dir;
> +
> +	dir = debugfs_create_dir("boottime", NULL);
> +
> +	(void) debugfs_create_file("bootgraph", S_IFREG | S_IRUGO,
> +				   dir, (void *)BOOTTIME_FILTER_NOTHING,
> +				   &boottime_debugfs_bootgraph_operations);
> +	(void) debugfs_create_file("bootgraph_all_except0", S_IFREG | S_IRUGO,
> +				   dir, (void *)BOOTTIME_FILTER_OUT_ZERO,
> +				   &boottime_debugfs_bootgraph_operations);
> +	(void) debugfs_create_file("bootgraph_larger100",
> +				   S_IFREG | S_IRUGO,
> +				   dir, (void *)BOOTTIME_FILTER_OUT_LESS_100,
> +				   &boottime_debugfs_bootgraph_operations);
> +	(void) debugfs_create_file("summary", S_IFREG | S_IRUGO,
> +				   dir, NULL,
> +				   &boottime_debugfs_summary_operations);
> +}
> +#else
> +#define boottime_debugfs_init(x)
> +#endif
> +
> +static ssize_t show_bootloader(struct device *dev,
> +			       struct device_attribute *attr,
> +			       char *buf)
> +{
> +	return sprintf(buf, "%ld\n", time_bootloader_done / 1000);
> +}
> +
> +static ssize_t show_kernel(struct device *dev,
> +			   struct device_attribute *attr,
> +			   char *buf)
> +{
> +	return sprintf(buf, "%ld\n",
> +		       (time_kernel_done - time_bootloader_done) / 1000);
> +}
> +
> +DEVICE_ATTR(kernel, 0444, show_kernel, NULL);
> +DEVICE_ATTR(bootloader, 0444, show_bootloader, NULL);
> +
> +static struct attribute *boottime_sysfs_entries[] = {
> +	&dev_attr_kernel.attr,
> +	&dev_attr_bootloader.attr,
> +	NULL
> +};
> +
> +static struct attribute_group boottime_attr_grp = {
> +	.name = NULL,
> +	.attrs = boottime_sysfs_entries,
> +};
> +
> +static int __init boottime_init(void)
> +{
> +	struct kobject *boottime_kobj;
> +
> +	boottime_kobj = kobject_create_and_add("boottime", NULL);
> +	if (!boottime_kobj) {
> +		printk(KERN_ERR "boottime: out of memory!\n");
> +		return -ENOMEM;
> +	}
> +
> +	if (sysfs_create_group(boottime_kobj, &boottime_attr_grp) < 0) {
> +		kobject_put(boottime_kobj);
> +		printk(KERN_ERR "boottime: Failed creating sysfs group\n");
> +		return -ENOMEM;
> +	}
> +
> +	boottime_debugfs_init();
> +
> +	return 0;
> +}
> +
> +late_initcall(boottime_init);
> diff --git a/init/main.c b/init/main.c
> index 313360f..c06afd0 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -69,6 +69,7 @@
>   #include <linux/slab.h>
>   #include <linux/perf_event.h>
>   #include <linux/file.h>
> +#include <linux/boottime.h>
>   
>   #include <asm/io.h>
>   #include <asm/bugs.h>
> @@ -679,6 +680,8 @@ int __init_or_module do_one_initcall(initcall_t fn)
>   	int count = preempt_count();
>   	int ret;
>   
> +	boottime_mark_symbolic(fn);
> +
>   	if (initcall_debug)
>   		ret = do_one_initcall_debug(fn);
>   	else
> @@ -804,6 +807,7 @@ static noinline int init_post(void)
>   {
>   	/* need to finish all async __init code before freeing the memory */
>   	async_synchronize_full();
> +	boottime_deactivate();
>   	free_initmem();
>   	mark_rodata_ro();
>   	system_state = SYSTEM_RUNNING;
> @@ -863,6 +867,7 @@ static int __init kernel_init(void * unused)
>   
>   	do_pre_smp_initcalls();
>   	lockup_detector_init();
> +	boottime_system_up();
>   
>   	smp_init();
>   	sched_init_smp();
> @@ -885,6 +890,7 @@ static int __init kernel_init(void * unused)
>   
>   	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
>   		ramdisk_execute_command = NULL;
> +		boottime_mark("mount+0x0/0x0");
>   		prepare_namespace();
>   	}