linux/mm
Andy Whitcroft cb2b95e1c6 [PATCH] zone handle unaligned zone boundaries
The buddy allocator has a requirement that boundaries between contigious
zones occur aligned with the the MAX_ORDER ranges.  Where they do not we
will incorrectly merge pages cross zone boundaries.  This can lead to pages
from the wrong zone being handed out.

Originally the buddy allocator would check that buddies were in the same
zone by referencing the zone start and end page frame numbers.  This was
removed as it became very expensive and the buddy allocator already made
the assumption that zones boundaries were aligned.

It is clear that not all configurations and architectures are honouring
this alignment requirement.  Therefore it seems safest to reintroduce
support for non-aligned zone boundaries.  This patch introduces a new check
when considering a page a buddy it compares the zone_table index for the
two pages and refuses to merge the pages where they do not match.  The
zone_table index is unique for each node/zone combination when
FLATMEM/DISCONTIGMEM is enabled and for each section/zone combination when
SPARSEMEM is enabled (a SPARSEMEM section is at least a MAX_ORDER size).

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00
..
bootmem.c [PATCH] x86_64: Handle empty PXMs that only contain hotplug memory 2006-04-09 11:53:16 -07:00
fadvise.c [PATCH] sys_sync_file_range() 2006-03-31 12:18:54 -08:00
filemap_xip.c [PATCH] replace inode_update_time with file_update_time 2006-01-10 08:01:30 -08:00
filemap.c [PATCH] Add find_get_pages_contig(): contiguous variant of find_get_pages() 2006-04-27 08:59:48 +02:00
filemap.h [PATCH] xip: reduce code duplication 2005-06-24 00:06:41 -07:00
fremap.c VM: add common helper function to create the page tables 2005-11-29 14:03:14 -08:00
highmem.c BUG_ON() Conversion in mm/highmem.c 2006-04-02 13:47:35 +02:00
hugetlb.c [PATCH] hugetlb: don't allow free hugetlb count fall below reserved count 2006-03-31 12:18:50 -08:00
internal.h [PATCH] remove set_page_count() outside mm/ 2006-03-22 07:54:02 -08:00
Kconfig [PATCH] mm: make page migration dependent on swap and NUMA 2006-03-25 08:22:50 -08:00
madvise.c [PATCH] Fix MADV_REMOVE protection checking 2006-04-17 18:22:18 -07:00
Makefile [PATCH] uninline zone helpers 2006-03-27 08:44:48 -08:00
memory_hotplug.c [PATCH] spanned_pages is not updated at a case of memory hot-add 2006-05-31 16:27:10 -07:00
memory.c [PATCH] Don't pass boot parameters to argv_init[] 2006-03-31 12:18:53 -08:00
mempolicy.c [PATCH] Remove cond_resched in gather_stats() 2006-04-20 07:54:03 -07:00
mempool.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial 2006-03-26 09:41:18 -08:00
migrate.c [PATCH] page migration: Fix fallback behavior for dirty pages 2006-05-01 18:17:45 -07:00
mincore.c [PATCH] freepgt: sys_mincore ignore FIRST_USER_PGD_NR 2005-04-19 13:29:20 -07:00
mlock.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
mmap.c [PATCH] overcommit: use totalreserve_pages 2006-04-11 06:18:32 -07:00
mmzone.c [PATCH] uninline zone helpers 2006-03-27 08:44:48 -08:00
mprotect.c [PATCH] Enable mprotect on huge pages 2006-03-22 07:54:03 -08:00
mremap.c [PATCH] move capable() to capability.h 2006-01-11 18:42:13 -08:00
msync.c The comment describing how MS_ASYNC works in msync.c is confusing 2006-03-24 18:30:53 +01:00
nommu.c [PATCH] overcommit: use totalreserve_pages for nommu 2006-04-11 06:18:32 -07:00
oom_kill.c [PATCH] mm: fix mm_struct reference counting bugs in mm/oom_kill.c 2006-04-19 09:13:50 -07:00
page_alloc.c [PATCH] zone handle unaligned zone boundaries 2006-06-23 07:42:45 -07:00
page_io.c [PATCH] mm: split page table lock 2005-10-29 21:40:42 -07:00
page-writeback.c [PATCH] page-writeback comment fixes 2006-04-11 06:18:46 -07:00
pdflush.c [PATCH] Swap Migration V5: PF_SWAPWRITE to allow writing to swap 2006-01-08 20:12:41 -08:00
prio_tree.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
readahead.c [PATCH] ext3_readdir: use generic readahead 2006-03-23 07:38:09 -08:00
rmap.c [PATCH] mm: more CONFIG_DEBUG_VM 2006-03-22 07:54:02 -08:00
shmem.c [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
slab.c [PATCH] slab.c: fix offslab_limit bug 2006-06-02 11:21:10 -07:00
slob.c [PATCH] mm/slob.c: for_each_possible_cpu(), not NR_CPUS 2006-04-19 09:13:49 -07:00
sparse.c [PATCH] SPARSEMEM incorrectly calculates section number 2006-05-21 12:59:17 -07:00
swap_state.c BUG_ON() Conversion in mm/swap_state.c 2006-04-01 01:25:12 +02:00
swap.c [PATCH] for_each_possible_cpu: fixes for generic part 2006-03-28 09:16:05 -08:00
swapfile.c [PATCH] mm: schedule find_trylock_page() removal 2006-03-31 12:18:49 -08:00
thrash.c [PATCH] temporarily disable swap token on memory pressure 2005-11-28 14:42:25 -08:00
tiny-shmem.c [PATCH] do_truncate() call fix in tiny-shmem.c 2006-01-12 09:08:49 -08:00
truncate.c [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem 2006-01-09 15:59:24 -08:00
util.c [PATCH] slab: optimize constant-size kzalloc calls 2006-03-25 08:22:49 -08:00
vmalloc.c BUG_ON() Conversion in mm/vmalloc.c 2006-04-01 01:26:09 +02:00
vmscan.c [PATCH] typo in vmscan.c 2006-06-11 15:27:37 -07:00