PM/Hibernate: Do not try to allocate too much memory too hard (rev. 2) (ef4aede3) · Commits · 戴 / test

kernel/power/snapshot.c

+39 −4

Original line number	Diff line number	Diff line
		@@ -1203,6 +1203,36 @@ 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
		*
		@@ -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;

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