[PATCH] swsusp: debugging (b918f6e6) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-power

+16 −1

Original line number	Diff line number	Diff line
		@@ -21,7 +21,7 @@ Description:
		these states.

		What: /sys/power/disk
		Date: August 2006
		Date: September 2006
		Contact: Rafael J. Wysocki <rjw@sisk.pl>
		Description:
		The /sys/power/disk file controls the operating mode of the
		@@ -39,6 +39,19 @@ Description:
		'reboot' - the memory image will be saved by the kernel and
		the system will be rebooted.

		Additionally, /sys/power/disk can be used to turn on one of the
		two testing modes of the suspend-to-disk mechanism: 'testproc'
		or 'test'. If the suspend-to-disk mechanism is in the
		'testproc' mode, writing 'disk' to /sys/power/state will cause
		the kernel to disable nonboot CPUs and freeze tasks, wait for 5
		seconds, unfreeze tasks and enable nonboot CPUs. If it is in
		the 'test' mode, writing 'disk' to /sys/power/state will cause
		the kernel to disable nonboot CPUs and freeze tasks, shrink
		memory, suspend devices, wait for 5 seconds, resume devices,
		unfreeze tasks and enable nonboot CPUs. Then, we are able to
		look in the log messages and work out, for example, which code
		is being slow and which device drivers are misbehaving.

		The suspend-to-disk method may be chosen by writing to this
		file one of the accepted strings:

		@@ -46,6 +59,8 @@ Description:
		'platform'
		'shutdown'
		'reboot'
		'testproc'
		'test'

		It will only change to 'firmware' or 'platform' if the system
		supports that.

Documentation/power/interface.txt

+13 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,17 @@ testing). The system will support either 'firmware' or 'platform', and
		that is known a priori. But, the user may choose 'shutdown' or
		'reboot' as alternatives.

		Additionally, /sys/power/disk can be used to turn on one of the two testing
		modes of the suspend-to-disk mechanism: 'testproc' or 'test'. If the
		suspend-to-disk mechanism is in the 'testproc' mode, writing 'disk' to
		/sys/power/state will cause the kernel to disable nonboot CPUs and freeze
		tasks, wait for 5 seconds, unfreeze tasks and enable nonboot CPUs. If it is
		in the 'test' mode, writing 'disk' to /sys/power/state will cause the kernel
		to disable nonboot CPUs and freeze tasks, shrink memory, suspend devices, wait
		for 5 seconds, resume devices, unfreeze tasks and enable nonboot CPUs. Then,
		we are able to look in the log messages and work out, for example, which code
		is being slow and which device drivers are misbehaving.

		Reading from this file will display what the mode is currently set
		to. Writing to this file will accept one of

		@@ -37,6 +48,8 @@ to. Writing to this file will accept one of
		'platform'
		'shutdown'
		'reboot'
		'testproc'
		'test'

		It will only change to 'firmware' or 'platform' if the system supports
		it.

include/linux/pm.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -116,7 +116,9 @@ typedef int __bitwise suspend_disk_method_t;
		#define PM_DISK_PLATFORM ((__force suspend_disk_method_t) 2)
		#define PM_DISK_SHUTDOWN ((__force suspend_disk_method_t) 3)
		#define PM_DISK_REBOOT ((__force suspend_disk_method_t) 4)
		#define PM_DISK_MAX ((__force suspend_disk_method_t) 5)
		#define PM_DISK_TEST ((__force suspend_disk_method_t) 5)
		#define PM_DISK_TESTPROC ((__force suspend_disk_method_t) 6)
		#define PM_DISK_MAX ((__force suspend_disk_method_t) 7)

		struct pm_ops {
		suspend_disk_method_t pm_disk_mode;

kernel/power/disk.c

+28 −9

Original line number	Diff line number	Diff line
		@@ -71,7 +71,7 @@ static inline void platform_finish(void)

		static int prepare_processes(void)
		{
		int error;
		int error = 0;

		pm_prepare_console();

		@@ -84,6 +84,12 @@ static int prepare_processes(void)
		goto thaw;
		}

		if (pm_disk_mode == PM_DISK_TESTPROC) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto thaw;
		}

		/* Free memory before shutting down devices. */
		if (!(error = swsusp_shrink_memory()))
		return 0;
		@@ -120,13 +126,21 @@ int pm_suspend_disk(void)
		if (error)
		return error;

		if (pm_disk_mode == PM_DISK_TESTPROC)
		goto Thaw;

		suspend_console();
		error = device_suspend(PMSG_FREEZE);
		if (error) {
		resume_console();
		printk("Some devices failed to suspend\n");
		unprepare_processes();
		return error;
		goto Thaw;
		}

		if (pm_disk_mode == PM_DISK_TEST) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto Done;
		}

		pr_debug("PM: snapshotting memory.\n");
		@@ -143,16 +157,17 @@ int pm_suspend_disk(void)
		power_down(pm_disk_mode);
		else {
		swsusp_free();
		unprepare_processes();
		return error;
		goto Thaw;
		}
		} else
		} else {
		pr_debug("PM: Image restored successfully.\n");
		}

		swsusp_free();
		Done:
		device_resume();
		resume_console();
		Thaw:
		unprepare_processes();
		return error;
		}
		@@ -249,6 +264,8 @@ static const char * const pm_disk_modes[] = {
		[PM_DISK_PLATFORM] = "platform",
		[PM_DISK_SHUTDOWN] = "shutdown",
		[PM_DISK_REBOOT] = "reboot",
		[PM_DISK_TEST] = "test",
		[PM_DISK_TESTPROC] = "testproc",
		};

		/**
		@@ -303,17 +320,19 @@ static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
		}
		}
		if (mode) {
		if (mode == PM_DISK_SHUTDOWN \|\| mode == PM_DISK_REBOOT)
		if (mode == PM_DISK_SHUTDOWN \|\| mode == PM_DISK_REBOOT \|\|
		mode == PM_DISK_TEST \|\| mode == PM_DISK_TESTPROC) {
		pm_disk_mode = mode;
		else {
		} else {
		if (pm_ops && pm_ops->enter &&
		(mode == pm_ops->pm_disk_mode))
		pm_disk_mode = mode;
		else
		error = -EINVAL;
		}
		} else
		} else {
		error = -EINVAL;
		}

		pr_debug("PM: suspend-to-disk mode set to '%s'\n",
		pm_disk_modes[mode]);

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