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| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2010-08-10 04:20:11 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-10 07:45:04 +0400 |
| commit | d2997b1042ec150616c1963b5e5e919ffd0b0ebf (patch) | |
| tree | c970746ad3d5c3e0ccbd1695d07144dbe4534ec4 /include/linux/swap.h | |
| parent | 966cca029f739716fbcc8068b8c6dfe381f86fc3 (diff) | |
| download | linux-d2997b1042ec150616c1963b5e5e919ffd0b0ebf.tar.xz | |
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 <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ondrej Zary <linux@rainbow-software.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
| -rw-r--r-- | include/linux/swap.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index ff4acea9bbdb..91c9d3fc8513 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 *); |