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| 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/hibernate.c | |
| parent | 966cca029f739716fbcc8068b8c6dfe381f86fc3 (diff) | |
| download | kernel_samsung_espresso10-d2997b1042ec150616c1963b5e5e919ffd0b0ebf.zip kernel_samsung_espresso10-d2997b1042ec150616c1963b5e5e919ffd0b0ebf.tar.gz kernel_samsung_espresso10-d2997b1042ec150616c1963b5e5e919ffd0b0ebf.tar.bz2 | |
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/hibernate.c')
| -rw-r--r-- | kernel/power/hibernate.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 8dc31e0..c779639 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) |