linux-toradex.git/kernel/power/process.c, branch tegra-9.12.14

PM: wakelock: Don't dump unfrozen task list when aborting try_to_freeze_tasks after less than one second

2010-02-04T05:27:07+00:00

Change-Id: Ib2976e5b97a5ee4ec9abd4d4443584d9257d0941
Signed-off-by: Arve Hjønnevåg

PM: wakelock: Abort task freezing if a wake lock is held.

2010-02-04T05:27:06+00:00

Avoids a problem where the device sometimes hangs for 20 seconds
before the screen is turned on.

oom: move oom_killer_enable()/oom_killer_disable to where they belong

2009-09-22T14:17:38+00:00

Signed-off-by: Alexey Dobriyan 
Acked-by: David Rientjes 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, PM/Freezer: Disable OOM killer when tasks are frozen

2009-06-17T02:47:40+00:00

Currently, the following scenario appears to be possible in theory:

* Tasks are frozen for hibernation or suspend.
* Free pages are almost exhausted.
* Certain piece of code in the suspend code path attempts to allocate
  some memory using GFP_KERNEL and allocation order less than or
  equal to PAGE_ALLOC_COSTLY_ORDER.
* __alloc_pages_internal() cannot find a free page so it invokes the
  OOM killer.
* The OOM killer attempts to kill a task, but the task is frozen, so
  it doesn't die immediately.
* __alloc_pages_internal() jumps to 'restart', unsuccessfully tries
  to find a free page and invokes the OOM killer.
* No progress can be made.

Although it is now hard to trigger during hibernation due to the memory
shrinking carried out by the hibernation code, it is theoretically
possible to trigger during suspend after the memory shrinking has been
removed from that code path.  Moreover, since memory allocations are
going to be used for the hibernation memory shrinking, it will be even
more likely to happen during hibernation.

To prevent it from happening, introduce the oom_killer_disabled switch
that will cause __alloc_pages_internal() to fail in the situations in
which the OOM killer would have been called and make the freezer set
this switch after tasks have been successfully frozen.

[akpm@linux-foundation.org: be nicer to the namespace]
Signed-off-by: Rafael J. Wysocki 
Cc: Fengguang Wu 
Cc: David Rientjes 
Acked-by: Pavel Machek 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

container freezer: skip frozen cgroups during power management resume

2008-10-20T15:52:34+00:00

When a system is resumed after a suspend, it will also unfreeze frozen
cgroups.

This patchs modifies the resume sequence to skip the tasks which are part
of a frozen control group.

Signed-off-by: Cedric Le Goater 
Signed-off-by: Matt Helsley 
Acked-by: Serge E. Hallyn 
Tested-by: Matt Helsley 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

container freezer: make refrigerator always available

2008-10-20T15:52:33+00:00

Now that the TIF_FREEZE flag is available in all architectures, extract
the refrigerator() and freeze_task() from kernel/power/process.c and make
it available to all.

The refrigerator() can now be used in a control group subsystem
implementing a control group freezer.

Signed-off-by: Cedric Le Goater 
Signed-off-by: Matt Helsley 
Acked-by: Serge E. Hallyn 
Tested-by: Matt Helsley 
Cc: "Rafael J. Wysocki" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pm: fix try_to_freeze_tasks()'s use of do_div()

2008-07-24T17:47:24+00:00

Fix try_to_freeze_tasks()'s use of do_div() on an s64 by making
elapsed_csecs64 a u64 instead and dividing that.

Possibly this should be guarded lest the interval calculation turn up
negative, but the possible negativity of the result of the division is
cast away anyway.

This was introduced by patch 438e2ce68dfd4af4cfcec2f873564fb921db4bb5.

Signed-off-by: David Howells 
Acked-by: "Rafael J. Wysocki" 
Acked-by: Pavel Machek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Freezer: Introduce PF_FREEZER_NOSIG

2008-07-16T21:27:03+00:00

The freezer currently attempts to distinguish kernel threads from
user space tasks by checking if their mm pointer is unset and it
does not send fake signals to kernel threads.  However, there are
kernel threads, mostly related to networking, that behave like
user space tasks and may want to be sent a fake signal to be frozen.

Introduce the new process flag PF_FREEZER_NOSIG that will be set
by default for all kernel threads and make the freezer only send
fake signals to the tasks having PF_FREEZER_NOSIG unset.  Provide
the set_freezable_with_signal() function to be called by the kernel
threads that want to be sent a fake signal for freezing.

This patch should not change the freezer's observable behavior.

Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Andi Kleen 
Acked-by: Pavel Machek 
Signed-off-by: Len Brown

freezer vs stopped or traced

2008-03-04T15:59:54+00:00

This changes the "freezer" code used by suspend/hibernate in its treatment
of tasks in TASK_STOPPED (job control stop) and TASK_TRACED (ptrace) states.

As I understand it, the intent of the "freezer" is to hold all tasks
from doing anything significant.  For this purpose, TASK_STOPPED and
TASK_TRACED are "frozen enough".  It's possible the tasks might resume
from ptrace calls (if the tracer were unfrozen) or from signals
(including ones that could come via timer interrupts, etc).  But this
doesn't matter as long as they quickly block again while "freezing" is
in effect.  Some minor adjustments to the signal.c code make sure that
try_to_freeze() very shortly follows all wakeups from both kinds of
stop.  This lets the freezer code safely leave stopped tasks unmolested.

Changing this fixes the longstanding bug of seeing after resuming from
suspend/hibernate your shell report "[1] Stopped" and the like for all
your jobs stopped by ^Z et al, as if you had freshly fg'd and ^Z'd them.
It also removes from the freezer the arcane special case treatment for
ptrace'd tasks, which relied on intimate knowledge of ptrace internals.

Signed-off-by: Roland McGrath 
Signed-off-by: Linus Torvalds

power: Use task_is_*

2007-12-06T22:34:47+00:00

Signed-off-by: Matthew Wilcox