linux-stable.git/include/linux/hugetlb.h, branch linux-2.6.38.y

Encode huge page size for VM_FAULT_HWPOISON errors

2010-10-08T07:32:46+00:00

This fixes a problem introduced with the hugetlb hwpoison handling

The user space SIGBUS signalling wants to know the size of the hugepage
that caused a HWPOISON fault.

Unfortunately the architecture page fault handlers do not have easy
access to the struct page.

Pass the information out in the fault error code instead.

I added a separate VM_FAULT_HWPOISON_LARGE bit for this case and encode
the hpage index in some free upper bits of the fault code. The small
page hwpoison keeps stays with the VM_FAULT_HWPOISON name to minimize
changes.

Also add code to hugetlb.h to convert that index into a page shift.

Will be used in a further patch.

Cc: Naoya Horiguchi 
Cc: fengguang.wu@intel.com
Signed-off-by: Andi Kleen

HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page()

2010-10-08T07:32:45+00:00

This check is necessary to avoid race between dequeue and allocation,
which can cause a free hugepage to be dequeued twice and get kernel unstable.

Signed-off-by: Naoya Horiguchi 
Signed-off-by: Wu Fengguang 
Acked-by: Mel Gorman 
Reviewed-by: Christoph Lameter 
Signed-off-by: Andi Kleen

hugetlb: redefine hugepage copy functions

2010-10-08T07:32:44+00:00

This patch modifies hugepage copy functions to have only destination
and source hugepages as arguments for later use.
The old ones are renamed from copy_{gigantic,huge}_page() to
copy_user_{gigantic,huge}_page().
This naming convention is consistent with that between copy_highpage()
and copy_user_highpage().

ChangeLog since v4:
- add blank line between local declaration and code
- remove unnecessary might_sleep()

ChangeLog since v2:
- change copy_huge_page() from macro to inline dummy function
  to avoid compile warning when !CONFIG_HUGETLB_PAGE.

Signed-off-by: Naoya Horiguchi 
Acked-by: Mel Gorman 
Reviewed-by: Christoph Lameter 
Signed-off-by: Andi Kleen

hugetlb: add allocate function for hugepage migration

2010-10-08T07:32:44+00:00

We can't use existing hugepage allocation functions to allocate hugepage
for page migration, because page migration can happen asynchronously with
the running processes and page migration users should call the allocation
function with physical addresses (not virtual addresses) as arguments.

ChangeLog since v3:
- unify alloc_buddy_huge_page() and alloc_buddy_huge_page_node()

ChangeLog since v2:
- remove unnecessary get/put_mems_allowed() (thanks to David Rientjes)

ChangeLog since v1:
- add comment on top of alloc_huge_page_no_vma()

Signed-off-by: Naoya Horiguchi 
Acked-by: Mel Gorman 
Signed-off-by: Jun'ichi Nomura 
Reviewed-by: Christoph Lameter 
Signed-off-by: Andi Kleen

HWPOISON, hugetlb: isolate corrupted hugepage

2010-08-11T07:22:46+00:00

If error hugepage is not in-use, we can fully recovery from error
by dequeuing it from freelist, so return RECOVERY.
Otherwise whether or not we can recovery depends on user processes,
so return DELAYED.

Dependency:
  "HWPOISON, hugetlb: enable error handling path for hugepage"

Signed-off-by: Naoya Horiguchi 
Cc: Andrew Morton 
Acked-by: Fengguang Wu 
Signed-off-by: Andi Kleen

hugetlb, rmap: add reverse mapping for hugepage

2010-08-11T07:21:15+00:00

This patch adds reverse mapping feature for hugepage by introducing
mapcount for shared/private-mapped hugepage and anon_vma for
private-mapped hugepage.

While hugepage is not currently swappable, reverse mapping can be useful
for memory error handler.

Without this patch, memory error handler cannot identify processes
using the bad hugepage nor unmap it from them. That is:
- for shared hugepage:
  we can collect processes using a hugepage through pagecache,
  but can not unmap the hugepage because of the lack of mapcount.
- for privately mapped hugepage:
  we can neither collect processes nor unmap the hugepage.
This patch solves these problems.

This patch include the bug fix given by commit 23be7468e8, so reverts it.

Dependency:
  "hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h"

ChangeLog since May 24.
- create hugetlb_inline.h and move is_vm_hugetlb_index() in it.
- move functions setting up anon_vma for hugepage into mm/rmap.c.

ChangeLog since May 13.
- rebased to 2.6.34
- fix logic error (in case that private mapping and shared mapping coexist)
- move is_vm_hugetlb_page() into include/linux/mm.h to use this function
  from linear_page_index()
- define and use linear_hugepage_index() instead of compound_order()
- use page_move_anon_rmap() in hugetlb_cow()
- copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart.
- revert commit 24be7468 completely

Signed-off-by: Naoya Horiguchi 
Cc: Andi Kleen 
Cc: Andrew Morton 
Cc: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: Larry Woodman 
Cc: Lee Schermerhorn 
Acked-by: Fengguang Wu 
Acked-by: Mel Gorman 
Signed-off-by: Andi Kleen

hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h

2010-08-11T07:20:41+00:00

is_vm_hugetlb_page() is a widely used inline function to insert hooks
into hugetlb code.
But we can't use it in pagemap.h because of circular dependency of
the header files. This patch removes this limitation.

Acked-by: Mel Gorman 
Acked-by: Fengguang Wu 
Signed-off-by: Naoya Horiguchi 
Signed-off-by: Andi Kleen

hugetlb: derive huge pages nodes allowed from task mempolicy

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

This patch derives a "nodes_allowed" node mask from the numa mempolicy of
the task modifying the number of persistent huge pages to control the
allocation, freeing and adjusting of surplus huge pages when the pool page
count is modified via the new sysctl or sysfs attribute
"nr_hugepages_mempolicy".  The nodes_allowed mask is derived as follows:

* For "default" [NULL] task mempolicy, a NULL nodemask_t pointer
  is produced.  This will cause the hugetlb subsystem to use
  node_online_map as the "nodes_allowed".  This preserves the
  behavior before this patch.
* For "preferred" mempolicy, including explicit local allocation,
  a nodemask with the single preferred node will be produced.
  "local" policy will NOT track any internode migrations of the
  task adjusting nr_hugepages.
* For "bind" and "interleave" policy, the mempolicy's nodemask
  will be used.
* Other than to inform the construction of the nodes_allowed node
  mask, the actual mempolicy mode is ignored.  That is, all modes
  behave like interleave over the resulting nodes_allowed mask
  with no "fallback".

See the updated documentation [next patch] for more information
about the implications of this patch.

Examples:

Starting with:

	Node 0 HugePages_Total:     0
	Node 1 HugePages_Total:     0
	Node 2 HugePages_Total:     0
	Node 3 HugePages_Total:     0

Default behavior [with or without this patch] balances persistent
hugepage allocation across nodes [with sufficient contiguous memory]:

	sysctl vm.nr_hugepages[_mempolicy]=32

yields:

	Node 0 HugePages_Total:     8
	Node 1 HugePages_Total:     8
	Node 2 HugePages_Total:     8
	Node 3 HugePages_Total:     8

Of course, we only have nr_hugepages_mempolicy with the patch,
but with default mempolicy, nr_hugepages_mempolicy behaves the
same as nr_hugepages.

Applying mempolicy--e.g., with numactl [using '-m' a.k.a.
'--membind' because it allows multiple nodes to be specified
and it's easy to type]--we can allocate huge pages on
individual nodes or sets of nodes.  So, starting from the
condition above, with 8 huge pages per node, add 8 more to
node 2 using:

	numactl -m 2 sysctl vm.nr_hugepages_mempolicy=40

This yields:

	Node 0 HugePages_Total:     8
	Node 1 HugePages_Total:     8
	Node 2 HugePages_Total:    16
	Node 3 HugePages_Total:     8

The incremental 8 huge pages were restricted to node 2 by the
specified mempolicy.

Similarly, we can use mempolicy to free persistent huge pages
from specified nodes:

	numactl -m 0,1 sysctl vm.nr_hugepages_mempolicy=32

yields:

	Node 0 HugePages_Total:     4
	Node 1 HugePages_Total:     4
	Node 2 HugePages_Total:    16
	Node 3 HugePages_Total:     8

The 8 huge pages freed were balanced over nodes 0 and 1.

[rientjes@google.com: accomodate reworked NODEMASK_ALLOC]
Signed-off-by: David Rientjes 
Signed-off-by: Lee Schermerhorn 
Acked-by: Mel Gorman 
Reviewed-by: Andi Kleen 
Cc: KAMEZAWA Hiroyuki 
Cc: Randy Dunlap 
Cc: Nishanth Aravamudan 
Cc: Adam Litke 
Cc: Andy Whitcroft 
Cc: Eric Whitney 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

const: mark struct vm_struct_operations

2009-09-27T18:39:25+00:00

* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

hugetlb_file_setup(): use C, not cpp

2009-09-25T00:11:24+00:00

Why macros are always wrong:

  mm/mmap.c: In function 'do_mmap_pgoff':
  mm/mmap.c:953: warning: unused variable 'user'

also, move a couple of struct forward-decls outside `#ifdef
CONFIG_HUGETLB_PAGE' - it's pointless and frequently harmful to make these
conditional (eg, this patch needed `struct user_struct').

Cc: Lee Schermerhorn 
Cc: Mel Gorman 
Cc: Nishanth Aravamudan 
Cc: David Rientjes 
Cc: Adam Litke 
Cc: Andy Whitcroft 
Cc: Eric Whitney 
Cc: Eric B Munson 
Cc: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds