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authorChen Yu <yu.c.chen@intel.com>2016-07-22 10:30:47 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-07-22 13:57:23 +0200
commitfe12c00d21bb4985fa8da282942250be21e7dd59 (patch)
tree35231867af10de4803b883b43e924ae785ee7faf /kernel
parent406f992e4a372dafbe3c2cff7efbb2002a5c8ebd (diff)
PM / hibernate: Introduce test_resume mode for hibernation
test_resume mode is to verify if the snapshot data written to swap device can be successfully restored to memory. It is useful to ease the debugging process on hibernation, since this mode can not only bypass the BIOSes/bootloader, but also the system re-initialization. To avoid the risk to break the filesystm on persistent storage, this patch resumes the image with tasks frozen. For example: echo test_resume > /sys/power/disk echo disk > /sys/power/state [ 187.306470] PM: Image saving progress: 70% [ 187.395298] PM: Image saving progress: 80% [ 187.476697] PM: Image saving progress: 90% [ 187.554641] PM: Image saving done. [ 187.558896] PM: Wrote 594600 kbytes in 0.90 seconds (660.66 MB/s) [ 187.566000] PM: S| [ 187.589742] PM: Basic memory bitmaps freed [ 187.594694] PM: Checking hibernation image [ 187.599865] PM: Image signature found, resuming [ 187.605209] PM: Loading hibernation image. [ 187.665753] PM: Basic memory bitmaps created [ 187.691397] PM: Using 3 thread(s) for decompression. [ 187.691397] PM: Loading and decompressing image data (148650 pages)... [ 187.889719] PM: Image loading progress: 0% [ 188.100452] PM: Image loading progress: 10% [ 188.244781] PM: Image loading progress: 20% [ 189.057305] PM: Image loading done. [ 189.068793] PM: Image successfully loaded Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/hibernate.c65
-rw-r--r--kernel/power/swap.c6
2 files changed, 50 insertions, 21 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 5f3523e18e46..0ee1df0a0bd6 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -52,6 +52,7 @@ enum {
#ifdef CONFIG_SUSPEND
HIBERNATION_SUSPEND,
#endif
+ HIBERNATION_TEST_RESUME,
/* keep last */
__HIBERNATION_AFTER_LAST
};
@@ -647,12 +648,39 @@ static void power_down(void)
cpu_relax();
}
+static int load_image_and_restore(void)
+{
+ int error;
+ unsigned int flags;
+
+ pr_debug("PM: Loading hibernation image.\n");
+
+ lock_device_hotplug();
+ error = create_basic_memory_bitmaps();
+ if (error)
+ goto Unlock;
+
+ error = swsusp_read(&flags);
+ swsusp_close(FMODE_READ);
+ if (!error)
+ hibernation_restore(flags & SF_PLATFORM_MODE);
+
+ printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
+ swsusp_free();
+ free_basic_memory_bitmaps();
+ Unlock:
+ unlock_device_hotplug();
+
+ return error;
+}
+
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
int hibernate(void)
{
int error, nr_calls = 0;
+ bool snapshot_test = false;
if (!hibernation_available()) {
pr_debug("PM: Hibernation not available.\n");
@@ -704,8 +732,12 @@ int hibernate(void)
pr_debug("PM: writing image.\n");
error = swsusp_write(flags);
swsusp_free();
- if (!error)
- power_down();
+ if (!error) {
+ if (hibernation_mode == HIBERNATION_TEST_RESUME)
+ snapshot_test = true;
+ else
+ power_down();
+ }
in_suspend = 0;
pm_restore_gfp_mask();
} else {
@@ -716,6 +748,12 @@ int hibernate(void)
free_basic_memory_bitmaps();
Thaw:
unlock_device_hotplug();
+ if (snapshot_test) {
+ pr_debug("PM: Checking hibernation image\n");
+ error = swsusp_check();
+ if (!error)
+ error = load_image_and_restore();
+ }
thaw_processes();
/* Don't bother checking whether freezer_test_done is true */
@@ -748,7 +786,6 @@ int hibernate(void)
static int software_resume(void)
{
int error, nr_calls = 0;
- unsigned int flags;
/*
* If the user said "noresume".. bail out early.
@@ -844,24 +881,7 @@ static int software_resume(void)
error = freeze_processes();
if (error)
goto Close_Finish;
-
- pr_debug("PM: Loading hibernation image.\n");
-
- lock_device_hotplug();
- error = create_basic_memory_bitmaps();
- if (error)
- goto Thaw;
-
- error = swsusp_read(&flags);
- swsusp_close(FMODE_READ);
- if (!error)
- hibernation_restore(flags & SF_PLATFORM_MODE);
-
- printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
- swsusp_free();
- free_basic_memory_bitmaps();
- Thaw:
- unlock_device_hotplug();
+ error = load_image_and_restore();
thaw_processes();
Finish:
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
@@ -887,6 +907,7 @@ static const char * const hibernation_modes[] = {
#ifdef CONFIG_SUSPEND
[HIBERNATION_SUSPEND] = "suspend",
#endif
+ [HIBERNATION_TEST_RESUME] = "test_resume",
};
/*
@@ -933,6 +954,7 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
+ case HIBERNATION_TEST_RESUME:
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
@@ -979,6 +1001,7 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
+ case HIBERNATION_TEST_RESUME:
hibernation_mode = mode;
break;
case HIBERNATION_PLATFORM:
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 160e1006640d..51cef8432154 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -348,6 +348,12 @@ static int swsusp_swap_check(void)
if (res < 0)
blkdev_put(hib_resume_bdev, FMODE_WRITE);
+ /*
+ * Update the resume device to the one actually used,
+ * so the test_resume mode can use it in case it is
+ * invoked from hibernate() to test the snapshot.
+ */
+ swsusp_resume_device = hib_resume_bdev->bd_dev;
return res;
}