1 files changed, 20 insertions, 5 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index ca0aacc24874..d69e3323a85d 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -41,6 +41,18 @@ static void swsusp_set_page_forbidden(struct page *);
 static void swsusp_unset_page_forbidden(struct page *);
 
 /*
+ * Number of bytes to reserve for memory allocations made by device drivers
+ * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
+ * cause image creation to fail (tunable via /sys/power/reserved_size).
+ */
+unsigned long reserved_size;
+
+void __init hibernate_reserved_size_init(void)
+{
+        reserved_size = SPARE_PAGES * PAGE_SIZE;
+}
+
+/*
  * Preferred image size in bytes (tunable via /sys/power/image_size).
  * When it is set to N, the image creating code will do its best to
  * ensure the image size will not exceed N bytes, but if that is
@@ -1263,11 +1275,13 @@ static unsigned long minimum_image_size(unsigned long saveable)
  * frame in use.  We also need a number of page frames to be free during
  * hibernation for allocations made while saving the image and for device
  * drivers, in case they need to allocate memory from their hibernation
- * callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES,
- * respectively, both of which are rough estimates).  To make this happen, we
- * compute the total number of available page frames and allocate at least
+ * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
+ * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
+ * /sys/power/reserved_size, respectively).  To make this happen, we compute the
+ * total number of available page frames and allocate at least
  *
- * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES
+ * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
+ *  + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
  *
  * of them, which corresponds to the maximum size of a hibernation image.
  *
@@ -1322,7 +1336,8 @@ int hibernate_preallocate_memory(void)
         count -= totalreserve_pages;
 
         /* Compute the maximum number of saveable pages to leave in memory. */
-        max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES;
+        max_size = (count - (size + PAGES_FOR_IO)) / 2
+                        - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
         /* Compute the desired number of image pages specified by image_size. */
         size = DIV_ROUND_UP(image_size, PAGE_SIZE);
         if (size > max_size)