linux-toradex.git/kernel/power/snapshot.c, branch v2.6.34.3

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

PM / Hibernate: Fix preallocating of memory

2010-02-26T19:39:13+00:00

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 
Cc: stable@kernel.org

PM / Hibernate: Remove trailing space in message

2010-02-26T19:39:13+00:00

Remove a trailing space from a message in swsusp_save().

Signed-off-by: Frans Pop 
Acked-by: Pavel Machek 
Signed-off-by: Rafael J. Wysocki

mm: don't use alloc_bootmem_low() where not strictly needed

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

Since alloc_bootmem() will never return inaccessible (via virtual
addressing) memory anyway, using the ..._low() variant only makes sense
when the physical address range of the allocated memory must fulfill
further constraints, espacially since on 64-bits (or more generally in all
cases where the pools the two variants allocate from are than the full
available range.

Probably the use in alloc_tce_table() could also be eliminated (based on
code inspection of pci-calgary_64.c), but that seems too risky given I
know nothing about that hardware and have no way to test it.

Signed-off-by: Jan Beulich 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM: Trivial fixes

2009-09-14T18:26:59+00:00

Fix the definition of BM_BITS_PER_BLOCK and kerneldoc
description of create_bm_block_list().

[rjw: Added changelog.]

Signed-off-by: Wu Fengguang 
Signed-off-by: Rafael J. Wysocki

PM / Hibernate / Memory hotplug: Always use for_each_populated_zone()

2009-09-14T18:26:59+00:00

Use for_each_populated_zone() instead of for_each_zone() in hibernation
code. This fixes a bug on s390, where we allow both config options
HIBERNATION and MEMORY_HOTPLUG, so that we also have a ZONE_MOVABLE
here. We only allow hibernation if no memory hotplug operation was
performed, so in fact both features can only be used exclusively, but
this way we don't need 2 differently configured (distribution) kernels.

If we have an unpopulated ZONE_MOVABLE, we allow hibernation but run
into a BUG_ON() in memory_bm_test/set/clear_bit() because hibernation
code iterates through all zones, not only the populated zones, in
several places. For example, swsusp_free() does for_each_zone() and
then checks for pfn_valid(), which is true even if the zone is not
populated, resulting in a BUG_ON() later because the pfn cannot be
found in the memory bitmap.

Replacing all occurences of for_each_zone() in hibernation code with
for_each_populated_zone() would fix this issue.

[rjw: Rebased on top of linux-next hibernation patches.]

Signed-off-by: Gerald Schaefer 
Acked-by: KOSAKI Motohiro 
Signed-off-by: Rafael J. Wysocki

PM/Hibernate: Do not try to allocate too much memory too hard (rev. 2)

2009-09-14T18:26:59+00:00

We want to avoid attempting to free too much memory too hard during
hibernation, so estimate the minimum size of the image to use as the
lower limit for preallocating memory.

The approach here is based on the (experimental) observation that we
can't free more page frames than the sum of:

* global_page_state(NR_SLAB_RECLAIMABLE)
* global_page_state(NR_ACTIVE_ANON)
* global_page_state(NR_INACTIVE_ANON)
* global_page_state(NR_ACTIVE_FILE)
* global_page_state(NR_INACTIVE_FILE)

minus

* global_page_state(NR_FILE_MAPPED)

Namely, if this number is subtracted from the number of saveable
pages in the system, we get a good estimate of the minimum reasonable
size of a hibernation image.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Wu Fengguang

PM/Hibernate: Do not release preallocated memory unnecessarily (rev. 2)

2009-09-14T18:26:58+00:00

Since the hibernation code is now going to use allocations of memory
to make enough room for the image, it can also use the page frames
allocated at this stage as image page frames.  The low-level
hibernation code needs to be rearranged for this purpose, but it
allows us to avoid freeing a great number of pages and allocating
these same pages once again later, so it generally is worth doing.

[rev. 2: Take highmem into account correctly.]

Signed-off-by: Rafael J. Wysocki

PM/Hibernate: Rework shrinking of memory

2009-09-14T18:26:58+00:00

Rework swsusp_shrink_memory() so that it calls shrink_all_memory()
just once to make some room for the image and then allocates memory
to apply more pressure to the memory management subsystem, if
necessary.

Unfortunately, we don't seem to be able to drop shrink_all_memory()
entirely just yet, because that would lead to huge performance
regressions in some test cases.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek

PM/Hibernate: Move memory shrinking to snapshot.c (rev. 2)

2009-06-12T19:32:32+00:00

A future patch is going to modify the memory shrinking code so that
it will make memory allocations to free memory instead of using an
artificial memory shrinking mechanism for that.  For this purpose it
is convenient to move swsusp_shrink_memory() from
kernel/power/swsusp.c to kernel/power/snapshot.c, because the new
memory-shrinking code is going to use things that are local to
kernel/power/snapshot.c .

[rev. 2: Make some functions static and remove their headers from
 kernel/power/power.h]

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Acked-by: Wu Fengguang