linux.git/mm/bootmem.c, branch v2.6.26-rc7

memory hotplug: make alloc_bootmem_section()

2008-04-28T15:58:25+00:00

alloc_bootmem_section() can allocate specified section's area.  This is used
for usemap to keep same section with pgdat by later patch.

Signed-off-by: Yasunori Goto 
Cc: Badari Pulavarty 
Cc: Yinghai Lu 
Cc: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory hotplug: register section/node id to free

2008-04-28T15:58:25+00:00

This patch set is to free pages which is allocated by bootmem for
memory-hotremove.  Some structures of memory management are allocated by
bootmem.  ex) memmap, etc.

To remove memory physically, some of them must be freed according to
circumstance.  This patch set makes basis to free those pages, and free
memmaps.

Basic my idea is using remain members of struct page to remember information
of users of bootmem (section number or node id).  When the section is
removing, kernel can confirm it.  By this information, some issues can be
solved.

  1) When the memmap of removing section is allocated on other
     section by bootmem, it should/can be free.
  2) When the memmap of removing section is allocated on the
     same section, it shouldn't be freed. Because the section has to be
     logical memory offlined already and all pages must be isolated against
     page allocater. If it is freed, page allocator may use it which will
     be removed physically soon.
  3) When removing section has other section's memmap,
     kernel will be able to show easily which section should be removed
     before it for user. (Not implemented yet)
  4) When the above case 2), the page isolation will be able to check and skip
     memmap's page when logical memory offline (offline_pages()).
     Current page isolation code fails in this case because this page is
     just reserved page and it can't distinguish this pages can be
     removed or not. But, it will be able to do by this patch.
     (Not implemented yet.)
  5) The node information like pgdat has similar issues. But, this
     will be able to be solved too by this.
     (Not implemented yet, but, remembering node id in the pages.)

Fortunately, current bootmem allocator just keeps PageReserved flags,
and doesn't use any other members of page struct. The users of
bootmem doesn't use them too.

This patch:

This is to register information which is node or section's id.  Kernel can
distinguish which node/section uses the pages allcated by bootmem.  This is
basis for hot-remove sections or nodes.

Signed-off-by: Yasunori Goto 
Cc: Badari Pulavarty 
Cc: Yinghai Lu 
Cc: Yasunori Goto 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: allow reserve_bootmem() cross nodes

2008-04-26T20:51:08+00:00

split reserve_bootmem_core() into two functions, one which checks
conflicts, and one which sets the bits.

and make reserve_bootmem to loop bdata_list to cross the nodes.

user could be crashkernel and ramdisk..., in case the range provided
by those externalities crosses the nodes.

Signed-off-by: Yinghai Lu 
Signed-off-by: Ingo Molnar

mm: offset align in alloc_bootmem()

2008-04-26T20:51:08+00:00

need offset alignment when node_boot_start's alignment is less than
the alignment required.

use local node_boot_start to match alignment - so don't add extra operation
in search loop.

Signed-off-by: Yinghai Lu 
Signed-off-by: Ingo Molnar

mm: fix alloc_bootmem_core to use fast searching for all nodes

2008-04-26T20:51:07+00:00

Make the nodes other than node 0 use bdata->last_success for fast
search too.

We need to use __alloc_bootmem_core() for vmemmap allocation for other
nodes when numa and sparsemem/vmemmap are enabled.

Also, make fail_block path increase i with incr only after ALIGN
to avoid extra increase when size is larger than align.

Signed-off-by: Yinghai Lu 
Signed-off-by: Ingo Molnar

mm: fix boundary checking in free_bootmem_core

2008-03-25T02:22:19+00:00

With numa enabled, some callers could have a range of memory on one node
but try to free that on other node.  This can cause some pages to be
freed wrongly.

For example: when we try to allocate 128g boot ram early for
gart/swiotlb, and free that range later so gart/swiotlb can get some
range afterwards.

With this patch, we don't need to care which node holds the range, just
loop to call free_bootmem_node for all online nodes.

This patch makes free_bootmem_core() more robust by trimming the sidx
and eidx according the ram range that the node has.

And make the free_bootmem_core handle this out of range case.  We could
use bdata_list to make sure the range can be freed for sure.  So next
time, we don't need to loop online nodes and could use free_bootmem
directly.

Signed-off-by: Yinghai Lu 
Cc: Andi Kleen 
Cc: Yasunori Goto 
Cc: KAMEZAWA Hiroyuki 
Acked-by: Ingo Molnar 
Tested-by: Ingo Molnar 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Introduce flags for reserve_bootmem()

2008-02-07T16:42:25+00:00

This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle 
Cc: 
Cc: "Eric W. Biederman" 
Cc: Vivek Goyal 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols

2006-12-07T16:39:44+00:00

In time for 2.6.20, we can get rid of this junk.

Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] enable booting a NUMA system where some nodes have no memory

2006-12-07T16:39:22+00:00

When booting a NUMA system with nodes that have no memory (eg by limiting
memory), bootmem_alloc_core tried to find pages in an uninitialized
bootmem_map.  This caused a null pointer access.  This fix adds a check, so
that NULL is returned.  That will enable the caller (bootmem_alloc_nopanic)
to alloc memory on other without a panic.

Signed-off-by: Christian Krafft 
Cc: Christoph Lameter 
Cc: Andy Whitcroft 
Cc: Martin Bligh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] bootmem: use MAX_DMA_ADDRESS instead of LOW32LIMIT

2006-09-26T15:48:49+00:00

Introduce ARCH_LOW_ADDRESS_LIMIT which can be set per architecture to
override the 4GB default limit used by the bootmem allocater within
__alloc_bootmem_low() and __alloc_bootmem_low_node().  E.g.  s390 needs a
2GB limit instead of 4GB.

Acked-by: Ingo Molnar 
Cc: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds