diff options
| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2010-08-09 17:20:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:45:04 -0700 |
| commit | d2997b1042ec150616c1963b5e5e919ffd0b0ebf (patch) | |
| tree | c970746ad3d5c3e0ccbd1695d07144dbe4534ec4 /kernel/power | |
| parent | 966cca029f739716fbcc8068b8c6dfe381f86fc3 (diff) | |
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 'kernel/power')
| -rw-r--r-- | kernel/power/hibernate.c | 1 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 1 | ||||
| -rw-r--r-- | kernel/power/swap.c | 6 |
3 files changed, 5 insertions, 3 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 8dc31e02ae1..c77963938bc 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -338,6 +338,7 @@ int hibernation_snapshot(int platform_mode) goto Close; suspend_console(); + hibernation_freeze_swap(); saved_mask = clear_gfp_allowed_mask(GFP_IOFS); error = dpm_suspend_start(PMSG_FREEZE); if (error) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index f6cd6faf84f..5e7edfb05e6 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1086,6 +1086,7 @@ void swsusp_free(void) buffer = NULL; alloc_normal = 0; alloc_highmem = 0; + hibernation_thaw_swap(); } /* Helper functions used for the shrinking of memory. */ diff --git a/kernel/power/swap.c b/kernel/power/swap.c index e6a5bdf61a3..5d0059eed3e 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -136,10 +136,10 @@ sector_t alloc_swapdev_block(int swap) { unsigned long offset; - offset = swp_offset(get_swap_page_of_type(swap)); + offset = swp_offset(get_swap_for_hibernation(swap)); if (offset) { if (swsusp_extents_insert(offset)) - swap_free(swp_entry(swap, offset)); + swap_free_for_hibernation(swp_entry(swap, offset)); else return swapdev_block(swap, offset); } @@ -163,7 +163,7 @@ void free_all_swap_pages(int swap) ext = container_of(node, struct swsusp_extent, node); rb_erase(node, &swsusp_extents); for (offset = ext->start; offset <= ext->end; offset++) - swap_free(swp_entry(swap, offset)); + swap_free_for_hibernation(swp_entry(swap, offset)); kfree(ext); } |