diff options
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/snapshot.c | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 2b1a7bc24c91..0a06b114dd33 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; |