4 files changed, 47 insertions, 7 deletions

diff --git a/kernel/power/console.c b/kernel/power/console.c
index fcdf0e14a47d..19c48aa5355d 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -16,6 +16,7 @@
 #define SUSPEND_CONSOLE	(MAX_NR_CONSOLES-1)
 
 static int orig_fgconsole, orig_kmsg;
+static bool vt_switch_done;
 
 static DEFINE_MUTEX(vt_switch_mutex);
 
@@ -136,17 +137,21 @@ void pm_prepare_console(void)
 	if (orig_fgconsole < 0)
 		return;
 
+	vt_switch_done = true;
+
 	orig_kmsg = vt_kmsg_redirect(SUSPEND_CONSOLE);
 	return;
 }
 
 void pm_restore_console(void)
 {
-	if (!pm_vt_switch())
+	if (!pm_vt_switch() && !vt_switch_done)
 		return;
 
 	if (orig_fgconsole >= 0) {
 		vt_move_to_console(orig_fgconsole, 0);
 		vt_kmsg_redirect(orig_kmsg);
 	}
+
+	vt_switch_done = false;
 }
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 9216e3b91d3b..1f1f30cca573 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -381,6 +381,23 @@ static int create_image(int platform_mode)
 	return error;
 }
 
+static void shrink_shmem_memory(void)
+{
+	struct sysinfo info;
+	unsigned long nr_shmem_pages, nr_freed_pages;
+
+	si_meminfo(&info);
+	nr_shmem_pages = info.sharedram; /* current page count used for shmem */
+	/*
+	 * The intent is to reclaim all shmem pages. Though shrink_all_memory() can
+	 * only reclaim about half of them, it's enough for creating the hibernation
+	 * image.
+	 */
+	nr_freed_pages = shrink_all_memory(nr_shmem_pages);
+	pr_debug("requested to reclaim %lu shmem pages, actually freed %lu pages\n",
+			nr_shmem_pages, nr_freed_pages);
+}
+
 /**
  * hibernation_snapshot - Quiesce devices and create a hibernation image.
  * @platform_mode: If set, use platform driver to prepare for the transition.
@@ -422,6 +439,15 @@ int hibernation_snapshot(int platform_mode)
 		goto Thaw;
 	}
 
+	/*
+	 * Device drivers may move lots of data to shmem in dpm_prepare(). The shmem
+	 * pages will use lots of system memory, causing hibernation image creation
+	 * fail due to insufficient free memory.
+	 * This call is to force flush the shmem pages to swap disk and reclaim
+	 * the system memory so that image creation can succeed.
+	 */
+	shrink_shmem_memory();
+
 	console_suspend_all();
 
 	error = dpm_suspend(PMSG_FREEZE);
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3d484630505a..3cf2d7e72567 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -8,6 +8,7 @@
 
 #include <linux/acpi.h>
 #include <linux/export.h>
+#include <linux/init.h>
 #include <linux/kobject.h>
 #include <linux/string.h>
 #include <linux/pm-trace.h>
@@ -112,6 +113,14 @@ int pm_notifier_call_chain(unsigned long val)
 /* If set, devices may be suspended and resumed asynchronously. */
 int pm_async_enabled = 1;
 
+static int __init pm_async_setup(char *str)
+{
+	if (!strcmp(str, "off"))
+		pm_async_enabled = 0;
+	return 1;
+}
+__setup("pm_async=", pm_async_setup);
+
 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
 			     char *buf)
 {
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 2af36cfe35cd..501df0676a61 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1536,7 +1536,7 @@ static unsigned long copy_data_pages(struct memory_bitmap *copy_bm,
 	memory_bm_position_reset(orig_bm);
 	memory_bm_position_reset(copy_bm);
 	copy_pfn = memory_bm_next_pfn(copy_bm);
-	for(;;) {
+	for (;;) {
 		pfn = memory_bm_next_pfn(orig_bm);
 		if (unlikely(pfn == BM_END_OF_MAP))
 			break;
@@ -2161,13 +2161,13 @@ static const char *check_image_kernel(struct swsusp_info *info)
 {
 	if (info->version_code != LINUX_VERSION_CODE)
 		return "kernel version";
-	if (strcmp(info->uts.sysname,init_utsname()->sysname))
+	if (strcmp(info->uts.sysname, init_utsname()->sysname))
 		return "system type";
-	if (strcmp(info->uts.release,init_utsname()->release))
+	if (strcmp(info->uts.release, init_utsname()->release))
 		return "kernel release";
-	if (strcmp(info->uts.version,init_utsname()->version))
+	if (strcmp(info->uts.version, init_utsname()->version))
 		return "version";
-	if (strcmp(info->uts.machine,init_utsname()->machine))
+	if (strcmp(info->uts.machine, init_utsname()->machine))
 		return "machine";
 	return NULL;
 }
@@ -2361,7 +2361,7 @@ static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm,
 		struct memory_bitmap *zero_bm)
 {
 	unsigned long decoded_pfn;
-        bool zero;
+	bool zero;
 	int j;
 
 	for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {