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-rw-r--r--kernel/power/snapshot.c43
1 files changed, 39 insertions, 4 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 2b1a7bc24c9..0a06b114dd3 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1204,6 +1204,36 @@ static void free_unnecessary_pages(void)
}
/**
+ * minimum_image_size - Estimate the minimum acceptable size of an image
+ * @saveable: Number of saveable pages in the system.
+ *
+ * We want to avoid attempting to free too much memory too hard, so estimate the
+ * minimum acceptable size of a hibernation image to use as the lower limit for
+ * preallocating memory.
+ *
+ * We assume that the minimum image size should be proportional to
+ *
+ * [number of saveable pages] - [number of pages that can be freed in theory]
+ *
+ * where the second term is the sum of (1) reclaimable slab pages, (2) active
+ * and (3) inactive anonymouns pages, (4) active and (5) inactive file pages,
+ * minus mapped file pages.
+ */
+static unsigned long minimum_image_size(unsigned long saveable)
+{
+ unsigned long size;
+
+ size = global_page_state(NR_SLAB_RECLAIMABLE)
+ + global_page_state(NR_ACTIVE_ANON)
+ + global_page_state(NR_INACTIVE_ANON)
+ + global_page_state(NR_ACTIVE_FILE)
+ + global_page_state(NR_INACTIVE_FILE)
+ - global_page_state(NR_FILE_MAPPED);
+
+ return saveable <= size ? 0 : saveable - size;
+}
+
+/**
* hibernate_preallocate_memory - Preallocate memory for hibernation image
*
* To create a hibernation image it is necessary to make a copy of every page
@@ -1220,8 +1250,8 @@ static void free_unnecessary_pages(void)
*
* If image_size is set below the number following from the above formula,
* the preallocation of memory is continued until the total number of saveable
- * pages in the system is below the requested image size or it is impossible to
- * allocate more memory, whichever happens first.
+ * pages in the system is below the requested image size or the minimum
+ * acceptable image size returned by minimum_image_size(), whichever is greater.
*/
int hibernate_preallocate_memory(void)
{
@@ -1282,6 +1312,11 @@ int hibernate_preallocate_memory(void)
goto out;
}
+ /* Estimate the minimum size of the image. */
+ pages = minimum_image_size(saveable);
+ if (size < pages)
+ size = min_t(unsigned long, pages, max_size);
+
/*
* Let the memory management subsystem know that we're going to need a
* large number of page frames to allocate and make it free some memory.
@@ -1294,8 +1329,8 @@ int hibernate_preallocate_memory(void)
* The number of saveable pages in memory was too high, so apply some
* pressure to decrease it. First, make room for the largest possible
* image and fail if that doesn't work. Next, try to decrease the size
- * of the image as much as indicated by image_size using allocations
- * from highmem and non-highmem zones separately.
+ * of the image as much as indicated by 'size' using allocations from
+ * highmem and non-highmem zones separately.
*/
pages_highmem = preallocate_image_highmem(highmem / 2);
alloc = (count - max_size) - pages_highmem;