linux-toradex.git/kernel/power, branch v2.6.33.17

PM / Hibernate: Fix free_unnecessary_pages()

2011-07-13T03:31:26+00:00

commit 4d4cf23cdde2f8f9324f5684a7f349e182039529 upstream.

There is a bug in free_unnecessary_pages() that causes it to
attempt to free too many pages in some cases, which triggers the
BUG_ON() in memory_bm_clear_bit() for copy_bm.  Namely, if
count_data_pages() is initially greater than alloc_normal, we get
to_free_normal equal to 0 and "save" greater from 0.  In that case,
if the sum of "save" and count_highmem_pages() is greater than
alloc_highmem, we subtract a positive number from to_free_normal.
Hence, since to_free_normal was 0 before the subtraction and is
an unsigned int, the result is converted to a huge positive number
that is used as the number of pages to free.

Fix this bug by checking if to_free_normal is actually greater
than or equal to the number we're going to subtract from it.

Signed-off-by: Rafael J. Wysocki 
Reported-and-tested-by: Matthew Garrett 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Avoid hitting OOM during preallocation of memory

2011-07-13T03:31:26+00:00

commit 6715045ddc7472a22be5e49d4047d2d89b391f45 upstream.

There is a problem in hibernate_preallocate_memory() that it calls
preallocate_image_memory() with an argument that may be greater than
the total number of available non-highmem memory pages.  If that's
the case, the OOM condition is guaranteed to trigger, which in turn
can cause significant slowdown to occur during hibernation.

To avoid that, make preallocate_image_memory() adjust its argument
before calling preallocate_image_pages(), so that the total number of
saveable non-highem pages left is not less than the minimum size of
a hibernation image.  Change hibernate_preallocate_memory() to try to
allocate from highmem if the number of pages allocated by
preallocate_image_memory() is too low.

Modify free_unnecessary_pages() to take all possible memory
allocation patterns into account.

Reported-by: KOSAKI Motohiro 
Signed-off-by: Rafael J. Wysocki 
Tested-by: M. Vefa Bicakci 
Signed-off-by: Greg Kroah-Hartman

PM: Free memory bitmaps if opening /dev/snapshot fails

2011-07-13T03:31:24+00:00

commit 8440f4b19494467883f8541b7aa28c7bbf6ac92b upstream.

When opening /dev/snapshot device, snapshot_open() creates memory
bitmaps which are freed in snapshot_release(). But if any of the
callbacks called by pm_notifier_call_chain() returns NOTIFY_BAD, open()
fails, snapshot_release() is never called and bitmaps are not freed.
Next attempt to open /dev/snapshot then triggers BUG_ON() check in
create_basic_memory_bitmaps(). This happens e.g. when vmwatchdog module
is active on s390x.

Signed-off-by: Michal Kubecek 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Return error code when alloc_image_page() fails

2011-03-21T19:45:10+00:00

commit 2e725a065b0153f0c449318da1923a120477633d upstream.

Currently we return 0 in swsusp_alloc() when alloc_image_page() fails.
Fix that.  Also remove unneeded "error" variable since the only
useful value of error is -ENOMEM.

[rjw: Fixed up the changelog and changed subject.]

Signed-off-by: Stanislaw Gruszka 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Fix PM_POST_* notification with user-space suspend

2011-03-21T19:44:24+00:00

commit 1497dd1d29c6a53fcd3c80f7ac8d0e0239e7389e upstream.

The user-space hibernation sends a wrong notification after the image
restoration because of thinko for the file flag check.  RDONLY
corresponds to hibernation and WRONLY to restoration, confusingly.

Signed-off-by: Takashi Iwai 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

Freezer: Fix buggy resume test for tasks frozen with cgroup freezer

2010-04-26T14:47:47+00:00

commit 5a7aadfe2fcb0f69e2acc1fbefe22a096e792fc9 upstream.

When the cgroup freezer is used to freeze tasks we do not want to thaw
those tasks during resume. Currently we test the cgroup freezer
state of the resuming tasks to see if the cgroup is FROZEN.  If so
then we don't thaw the task. However, the FREEZING state also indicates
that the task should remain frozen.

This also avoids a problem pointed out by Oren Ladaan: the freezer state
transition from FREEZING to FROZEN is updated lazily when userspace reads
or writes the freezer.state file in the cgroup filesystem. This means that
resume will thaw tasks in cgroups which should be in the FROZEN state if
there is no read/write of the freezer.state file to trigger this
transition before suspend.

NOTE: Another "simple" solution would be to always update the cgroup
freezer state during resume. However it's a bad choice for several reasons:
Updating the cgroup freezer state is somewhat expensive because it requires
walking all the tasks in the cgroup and checking if they are each frozen.
Worse, this could easily make resume run in N^2 time where N is the number
of tasks in the cgroup. Finally, updating the freezer state from this code
path requires trickier locking because of the way locks must be ordered.

Instead of updating the freezer state we rely on the fact that lazy
updates only manage the transition from FREEZING to FROZEN. We know that
a cgroup with the FREEZING state may actually be FROZEN so test for that
state too. This makes sense in the resume path even for partially-frozen
cgroups -- those that really are FREEZING but not FROZEN.

Reported-by: Oren Ladaan 
Signed-off-by: Matt Helsley 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Fix preallocating of memory

2010-03-15T16:06:10+00:00

commit a9c9b4429df437982d2fbfab1f4b46b01329e9ed upstream.

The hibernate memory preallocation code allocates memory to push some
user space data out of physical RAM, so that the hibernation image is
not too large.  It allocates more memory than necessary for creating
the image, so it has to release some pages to make room for
allocations made while suspending devices and disabling nonboot CPUs,
or the system will hang due to the lack of free pages to allocate
from.  Unfortunately, the function used for freeing these pages,
free_unnecessary_pages(), contains a bug that prevents it from doing
the job on all systems without highmem.

Fix this problem, which is a regression from the 2.6.30 kernel, by
using the right condition for the termination of the loop in
free_unnecessary_pages().

Signed-off-by: Rafael J. Wysocki 
Reported-and-tested-by: Alan Jenkins 
Signed-off-by: Greg Kroah-Hartman

vt: introduce and use vt_kmsg_redirect() function

2009-12-15T16:53:28+00:00

The kernel offers with TIOCL_GETKMSGREDIRECT ioctl() the possibility to
redirect the kernel messages to a specific console.

However, since it's not possible to switch to the kernel message console
after a panic(), it would be nice if the kernel would print the panic
message on the current console.

This patch series adds a new interface to access the global kmsg_redirect
variable by a function to be able to use it in code where
CONFIG_VT_CONSOLE is not set (kernel/panic.c).

This patch:

Instead of using and exporting a global value kmsg_redirect, introduce a
function vt_kmsg_redirect() that both can set and return the console where
messages are printed.

Change all users of kmsg_redirect (the VT code itself and kernel/power.c)
to the new interface.

The main advantage is that vt_kmsg_redirect() can also be used when
CONFIG_VT_CONSOLE is not set.

Signed-off-by: Bernhard Walle 
Cc: Alan Cox 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM / Runtime: Export the PM runtime workqueue

2009-12-06T15:17:56+00:00

This patch (as1306) exports the PM runtime workqueue for use by
loadable modules.

Signed-off-by: Alan Stern 
Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Swap, use KERN_CONT

2009-12-06T15:16:24+00:00

Use KERN_CONT in save_image() for printks, so that anybody won't
try to add a loglevel.

Signed-off-by: Jiri Slaby 
Signed-off-by: Rafael J. Wysocki