linux-stable.git/mm/memory_hotplug.c, branch linux-2.6.25.y

memory_hotplug: always initialize pageblock bitmap

2008-06-09T18:26:59+00:00

commit 76cdd58e558669366adfaded436fda01b30cce3e upstream

Trying to online a new memory section that was added via memory hotplug
sometimes results in crashes when the new pages are added via __free_page.
 Reason for that is that the pageblock bitmap isn't initialized and hence
contains random stuff.  That means that get_pageblock_migratetype()
returns also random stuff and therefore

	list_add(&page->lru,
		&zone->free_area[order].free_list[migratetype]);

in __free_one_page() tries to do a list_add to something that isn't even
necessarily a list.

This happens since 86051ca5eaf5e560113ec7673462804c54284456 ("mm: fix
usemap initialization") which makes sure that the pageblock bitmap gets
only initialized for pages present in a zone.  Unfortunately for hot-added
memory the zones "grow" after the memmap and the pageblock memmap have
been initialized.  Which means that the new pages have an unitialized
bitmap.  To solve this the calls to grow_zone_span() and grow_pgdat_span()
are moved to __add_zone() just before the initialization happens.

The patch also moves the two functions since __add_zone() is the only
caller and I didn't want to add a forward declaration.

Signed-off-by: Heiko Carstens 
Cc: Andy Whitcroft 
Cc: Dave Hansen 
Cc: Gerald Schaefer 
Cc: KAMEZAWA Hiroyuki 
Cc: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Chris Wright

Page allocator: clean up pcp draining functions

2008-02-05T17:44:17+00:00

- Add comments explaing how drain_pages() works.

- Eliminate useless functions

- Rename drain_all_local_pages to drain_all_pages(). It does drain
  all pages not only those of the local processor.

- Eliminate useless interrupt off / on sequences. drain_pages()
  disables interrupts on its own. The execution thread is
  pinned to processor by the caller. So there is no need to
  disable interrupts.

- Put drain_all_pages() declaration in gfp.h and remove the
  declarations from suspend.h and from mm/memory_hotplug.c

- Make software suspend call drain_all_pages(). The draining
  of processor local pages is may not the right approach if
  software suspend wants to support SMP. If they call drain_all_pages
  then we can make drain_pages() static.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Christoph Lameter 
Acked-by: Mel Gorman 
Cc: "Rafael J. Wysocki" 
Cc: Daniel Walker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Add IORESOUCE_BUSY flag for System RAM

2007-11-15T02:45:39+00:00

i386 and x86-64 registers System RAM as IORESOURCE_MEM | IORESOURCE_BUSY.

But ia64 registers it as IORESOURCE_MEM only.
In addition, memory hotplug code registers new memory as IORESOURCE_MEM too.

This difference causes a failure of memory unplug of x86-64.  This patch
fixes it.

This patch adds IORESOURCE_BUSY to avoid potential overlap mapping by PCI
device.

Signed-off-by: Yasunori Goto 
Signed-off-by: Badari Pulavarty 
Cc: Luck, Tony" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory hotremove: unset migrate type "ISOLATE" after removal

2007-11-15T02:45:38+00:00

We should unset migrate type "ISOLATE" when we successfully removed memory.
 But current code has BUG and cannot works well.

This patch also includes bugfix?  to change get_pageblock_flags to
get_pageblock_migratetype().

Thanks to Badari Pulavarty for finding this.

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: Badari Pulavarty 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory hotplug: rearrange memory hotplug notifier

2007-10-22T15:13:17+00:00

Current memory notifier has some defects yet.  (Fortunately, nothing uses
it.) This patch is to fix and rearrange for them.

  - Add information of start_pfn, nr_pages, and node id if node status is
    changes from/to memoryless node for callback functions.
    Callbacks can't do anything without those information.
  - Add notification going-online status.
    It is necessary for creating per node structure before the node's
    pages are available.
  - Move GOING_OFFLINE status notification after page isolation.
    It is good place for return memory like cache for callback,
    because returned page is not used again.
  - Make CANCEL events for rollingback when error occurs.
  - Delete MEM_MAPPING_INVALID notification. It will be not used.
  - Fix compile error of (un)register_memory_notifier().

Signed-off-by: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

spelling fixes: mm/

2007-10-19T23:27:18+00:00

Spelling fixes in mm/.

Signed-off-by: Simon Arlott 
Signed-off-by: Adrian Bunk

fix memory hot remove not configured case.

2007-10-16T16:43:02+00:00

Now, arch dependent code around CONFIG_MEMORY_HOTREMOVE is a mess.
This patch cleans up them. This is against 2.6.23-rc6-mm1.

 - fix compile failure on ia64/ CONFIG_MEMORY_HOTPLUG && !CONFIG_MEMORY_HOTREMOVE case.
 - For !CONFIG_MEMORY_HOTREMOVE, add generic no-op remove_memory(),
   which returns -EINVAL.
 - removed remove_pages() only used in powerpc.
 - removed no-op remove_memory() in i386, sh, sparc64, x86_64.

 - only powerpc returns -ENOSYS at memory hot remove(no-op). changes it
   to return -EINVAL.

Note:
Currently, only ia64 supports CONFIG_MEMORY_HOTREMOVE. I welcome other
archs if there are requirements and testers.

Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory unplug: page offline

2007-10-16T16:43:02+00:00

Logic.
 - set all pages in  [start,end)  as isolated migration-type.
   by this, all free pages in the range will be not-for-use.
 - Migrate all LRU pages in the range.
 - Test all pages in the range's refcnt is zero or not.

Todo:
 - allocate migration destination page from better area.
 - confirm page_count(page)== 0 && PageReserved(page) page is safe to be freed..
 (I don't like this kind of page but..
 - Find out pages which cannot be migrated.
 - more running tests.
 - Use reclaim for unplugging other memory type area.

Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory unplug: memory hotplug cleanup

2007-10-16T16:43:01+00:00

A clean up patch for "scanning memory resource [start, end)" operation.

Now, find_next_system_ram() function is used in memory hotplug, but this
interface is not easy to use and codes are complicated.

This patch adds walk_memory_resouce(start,len,arg,func) function.
The function 'func' is called per valid memory resouce range in [start,pfn).

[pbadari@us.ibm.com: Error handling in walk_memory_resource()]
Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Badari Pulavarty 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Memoryless nodes: introduce mask of nodes with memory

2007-10-16T16:42:58+00:00

It is necessary to know if nodes have memory since we have recently begun to
add support for memoryless nodes.  For that purpose we introduce a two new
node states: N_HIGH_MEMORY and N_NORMAL_MEMORY.

A node has its bit in N_HIGH_MEMORY set if it has any memory regardless of the
type of mmemory.  If a node has memory then it has at least one zone defined
in its pgdat structure that is located in the pgdat itself.

A node has its bit in N_NORMAL_MEMORY set if it has a lower zone than
ZONE_HIGHMEM.  This means it is possible to allocate memory that is not
subject to kmap.

N_HIGH_MEMORY and N_NORMAL_MEMORY can then be used in various places to insure
that we do the right thing when we encounter a memoryless node.

[akpm@linux-foundation.org: build fix]
[Lee.Schermerhorn@hp.com: update N_HIGH_MEMORY node state for memory hotadd]
[y-goto@jp.fujitsu.com: Fix memory hotplug + sparsemem build]
Signed-off-by: Lee Schermerhorn 
Signed-off-by: Nishanth Aravamudan 
Signed-off-by: Christoph Lameter 
Acked-by: Bob Picco 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Signed-off-by: Yasunori Goto 
Signed-off-by: Paul Mundt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds