From d2997b1042ec150616c1963b5e5e919ffd0b0ebf Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Mon, 9 Aug 2010 17:20:11 -0700 Subject: hibernation: freeze swap at hibernation When taking a memory snapshot in hibernate_snapshot(), all (directly called) memory allocations use GFP_ATOMIC. Hence swap misusage during hibernation never occurs. But from a pessimistic point of view, there is no guarantee that no page allcation has __GFP_WAIT. It is better to have a global indication "we enter hibernation, don't use swap!". This patch tries to freeze new-swap-allocation during hibernation. (All user processes are frozenm so swapin is not a concern). This way, no updates will happen to swap_map[] between hibernate_snapshot() and save_image(). Swap is thawed when swsusp_free() is called. We can be assured that swap corruption will not occur. Signed-off-by: KAMEZAWA Hiroyuki Cc: "Rafael J. Wysocki" Cc: Hugh Dickins Cc: KOSAKI Motohiro Cc: Ondrej Zary Cc: Balbir Singh Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index ff4acea9bbd..91c9d3fc851 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -316,7 +316,6 @@ extern long nr_swap_pages; extern long total_swap_pages; extern void si_swapinfo(struct sysinfo *); extern swp_entry_t get_swap_page(void); -extern swp_entry_t get_swap_page_of_type(int); extern int valid_swaphandles(swp_entry_t, unsigned long *); extern int add_swap_count_continuation(swp_entry_t, gfp_t); extern void swap_shmem_alloc(swp_entry_t); @@ -333,6 +332,13 @@ extern int reuse_swap_page(struct page *); extern int try_to_free_swap(struct page *); struct backing_dev_info; +#ifdef CONFIG_HIBERNATION +void hibernation_freeze_swap(void); +void hibernation_thaw_swap(void); +swp_entry_t get_swap_for_hibernation(int type); +void swap_free_for_hibernation(swp_entry_t val); +#endif + /* linux/mm/thrash.c */ extern struct mm_struct *swap_token_mm; extern void grab_swap_token(struct mm_struct *); -- cgit v1.2.3-70-g09d2