From: Rafael J. Wysocki <rjw@sisk.pl>
Date: Mon, 20 Sep 2010 17:44:56 +0000 (+0200)
Subject: PM / Hibernate: Make default image size depend on total RAM size
X-Git-Tag: v2.6.35.12~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3b49f6609e293e8a9d17f24911a2dc771ee3679;p=thirdparty%2Fkernel%2Fstable.git

PM / Hibernate: Make default image size depend on total RAM size

[ upstream commit ac5c24ec1e983313ef0015258fba6f630e54e7cf ]

The default hibernation image size is currently hard coded and euqal
to 500 MB, which is not a reasonable default on many contemporary
systems.  Make it equal 2/5 of the total RAM size (this is slightly
below the maximum, i.e. 1/2 of the total RAM size, and seems to be
generally suitable).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: M. Vefa Bicakci <bicave@superonline.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---

diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index e67211fe0ee2f..c537834af0056 100644
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -57,7 +57,7 @@ smallest image possible.  In particular, if "0" is written to this file, the
 suspend image will be as small as possible.
 
 Reading from this file will display the current image size limit, which
-is set to 500 MB by default.
+is set to 2/5 of available RAM by default.
 
 /sys/power/pm_trace controls the code which saves the last PM event point in
 the RTC across reboots, so that you can debug a machine that just hangs
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b58800b21fc01..51e2643e2d9da 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -266,6 +266,7 @@ static int __init pm_init(void)
 	int error = pm_start_workqueue();
 	if (error)
 		return error;
+	hibernate_image_size_init();
 	power_kobj = kobject_create_and_add("power", NULL);
 	if (!power_kobj)
 		return -ENOMEM;
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 006270fe382d7..54580cb4eaa71 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -14,6 +14,9 @@ struct swsusp_info {
 } __attribute__((aligned(PAGE_SIZE)));
 
 #ifdef CONFIG_HIBERNATION
+/* kernel/power/snapshot.c */
+extern void __init hibernate_image_size_init(void);
+
 #ifdef CONFIG_ARCH_HIBERNATION_HEADER
 /* Maximum size of architecture specific data in a hibernation header */
 #define MAX_ARCH_HEADER_SIZE	(sizeof(struct new_utsname) + 4)
@@ -49,7 +52,11 @@ static inline char *check_image_kernel(struct swsusp_info *info)
 extern int hibernation_snapshot(int platform_mode);
 extern int hibernation_restore(int platform_mode);
 extern int hibernation_platform_enter(void);
-#endif
+
+#else /* !CONFIG_HIBERNATION */
+
+static inline void hibernate_image_size_init(void) {}
+#endif /* !CONFIG_HIBERNATION */
 
 extern int pfn_is_nosave(unsigned long);
 
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index f2f61fa7eb99f..4d8548da48c55 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -46,7 +46,12 @@ static void swsusp_unset_page_forbidden(struct page *);
  * size will not exceed N bytes, but if that is impossible, it will
  * try to create the smallest image possible.
  */
-unsigned long image_size = 500 * 1024 * 1024;
+unsigned long image_size;
+
+void __init hibernate_image_size_init(void)
+{
+	image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE;
+}
 
 /* List of PBEs needed for restoring the pages that were allocated before
  * the suspend and included in the suspend image, but have also been