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| author | Rainer Fiebig <jrf@mailbox.org> | 2017-12-22 11:13:59 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-01-05 14:46:25 +0100 |
| commit | bdbc98abb3aa323f6323b11db39c740e6f8fc5b1 (patch) | |
| tree | 59a2b638f06ac896f3993c36953a2ea53cff5dcc /kernel/power | |
| parent | Linux 4.15-rc6 (diff) | |
| download | linux-bdbc98abb3aa323f6323b11db39c740e6f8fc5b1.tar.xz linux-bdbc98abb3aa323f6323b11db39c740e6f8fc5b1.zip | |
PM: hibernate: Do not subtract NR_FILE_MAPPED in minimum_image_size()
s2disk/s2both may fail unnecessarily and erratically if NR_FILE_MAPPED
is high - for instance when using VMs with VirtualBox and perhaps VMware
Player. In those situations s2disk becomes unreliable and therefore
unusable.
A typical scenario is: user issues a s2disk and it fails. User issues
a second s2disk immediately after that and it succeeds. And user
wonders why.
The problem is caused by minimum_image_size() in snapshot.c. The
value it returns is roughly 100% too high because NR_FILE_MAPPED is
subtracted in its calculation. Eventually the number of preallocated
image pages is falsely too low.
This doesn't matter as long as NR_FILE_MAPPED-values are in a normal
range or in 32bit-environments as the code allows for allocation of
additional pages from highmem.
But with the high values generated by VirtualBox-VMs (a 2-GB-VM causes
NR_FILE_MAPPED go up by 2 GB) it may lead to failure in 64bit-systems.
Not subtracting NR_FILE_MAPPED in minimum_image_size() solves the
problem.
I've done at least hundreds of successful s2both/s2disk now on an
x86_64 system (with and without VirtualBox) which gives me some
confidence that this is right. It has turned s2disk/s2both from
unusable into 100% reliable.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=97201
Signed-off-by: Rainer Fiebig <jrf@mailbox.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/snapshot.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index bce0464524d8..3d37c279c090 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1645,8 +1645,7 @@ static unsigned long free_unnecessary_pages(void) * [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 anonymous pages, (4) active and (5) inactive file pages, - * minus mapped file pages. + * and (3) inactive anonymous pages, (4) active and (5) inactive file pages. */ static unsigned long minimum_image_size(unsigned long saveable) { @@ -1656,8 +1655,7 @@ static unsigned long minimum_image_size(unsigned long saveable) + global_node_page_state(NR_ACTIVE_ANON) + global_node_page_state(NR_INACTIVE_ANON) + global_node_page_state(NR_ACTIVE_FILE) - + global_node_page_state(NR_INACTIVE_FILE) - - global_node_page_state(NR_FILE_MAPPED); + + global_node_page_state(NR_INACTIVE_FILE); return saveable <= size ? 0 : saveable - size; } |