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authorRafael J. Wysocki <rjw@sisk.pl>2009-06-11 23:11:17 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2009-06-12 21:32:32 +0200
commitfe419535d82724314bbf1244a0e740e4ea1bd3ae (patch)
treeceefd93df91b6325a99d481e79411dc310e3d27e /kernel/power/snapshot.c
parentc6f37f12197ac3bd2e5a35f2f0e195ae63d437de (diff)
PM/Hibernate: Move memory shrinking to snapshot.c (rev. 2)
A future patch is going to modify the memory shrinking code so that it will make memory allocations to free memory instead of using an artificial memory shrinking mechanism for that. For this purpose it is convenient to move swsusp_shrink_memory() from kernel/power/swsusp.c to kernel/power/snapshot.c, because the new memory-shrinking code is going to use things that are local to kernel/power/snapshot.c . [rev. 2: Make some functions static and remove their headers from kernel/power/power.h] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Diffstat (limited to 'kernel/power/snapshot.c')
-rw-r--r--kernel/power/snapshot.c80
1 files changed, 78 insertions, 2 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 33e2e4a819f..523a451b45d 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -39,6 +39,14 @@ static int swsusp_page_is_free(struct page *);
static void swsusp_set_page_forbidden(struct page *);
static void swsusp_unset_page_forbidden(struct page *);
+/*
+ * Preferred image size in bytes (tunable via /sys/power/image_size).
+ * When it is set to N, swsusp will do its best to ensure the image
+ * 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;
+
/* List of PBEs needed for restoring the pages that were allocated before
* the suspend and included in the suspend image, but have also been
* allocated by the "resume" kernel, so their contents cannot be written
@@ -840,7 +848,7 @@ static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
* pages.
*/
-unsigned int count_highmem_pages(void)
+static unsigned int count_highmem_pages(void)
{
struct zone *zone;
unsigned int n = 0;
@@ -902,7 +910,7 @@ static struct page *saveable_page(struct zone *zone, unsigned long pfn)
* pages.
*/
-unsigned int count_data_pages(void)
+static unsigned int count_data_pages(void)
{
struct zone *zone;
unsigned long pfn, max_zone_pfn;
@@ -1058,6 +1066,74 @@ void swsusp_free(void)
buffer = NULL;
}
+/**
+ * swsusp_shrink_memory - Try to free as much memory as needed
+ *
+ * ... but do not OOM-kill anyone
+ *
+ * Notice: all userland should be stopped before it is called, or
+ * livelock is possible.
+ */
+
+#define SHRINK_BITE 10000
+static inline unsigned long __shrink_memory(long tmp)
+{
+ if (tmp > SHRINK_BITE)
+ tmp = SHRINK_BITE;
+ return shrink_all_memory(tmp);
+}
+
+int swsusp_shrink_memory(void)
+{
+ long tmp;
+ struct zone *zone;
+ unsigned long pages = 0;
+ unsigned int i = 0;
+ char *p = "-\\|/";
+ struct timeval start, stop;
+
+ printk(KERN_INFO "PM: Shrinking memory... ");
+ do_gettimeofday(&start);
+ do {
+ long size, highmem_size;
+
+ highmem_size = count_highmem_pages();
+ size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES;
+ tmp = size;
+ size += highmem_size;
+ for_each_populated_zone(zone) {
+ tmp += snapshot_additional_pages(zone);
+ if (is_highmem(zone)) {
+ highmem_size -=
+ zone_page_state(zone, NR_FREE_PAGES);
+ } else {
+ tmp -= zone_page_state(zone, NR_FREE_PAGES);
+ tmp += zone->lowmem_reserve[ZONE_NORMAL];
+ }
+ }
+
+ if (highmem_size < 0)
+ highmem_size = 0;
+
+ tmp += highmem_size;
+ if (tmp > 0) {
+ tmp = __shrink_memory(tmp);
+ if (!tmp)
+ return -ENOMEM;
+ pages += tmp;
+ } else if (size > image_size / PAGE_SIZE) {
+ tmp = __shrink_memory(size - (image_size / PAGE_SIZE));
+ pages += tmp;
+ }
+ printk("\b%c", p[i++%4]);
+ } while (tmp > 0);
+ do_gettimeofday(&stop);
+ printk("\bdone (%lu pages freed)\n", pages);
+ swsusp_show_speed(&start, &stop, pages, "Freed");
+
+ return 0;
+}
+
#ifdef CONFIG_HIGHMEM
/**
* count_pages_for_highmem - compute the number of non-highmem pages