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7ad71f960f
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Yinghai Lu 7ad71f960f memblock: free allocated memblock_reserved_regions later 
commit 29f6738609 upstream.

memblock_free_reserved_regions() calls memblock_free(), but
memblock_free() would double reserved.regions too, so we could free the
old range for reserved.regions.

Also tj said there is another bug which could be related to this.

| I don't think we're saving any noticeable
| amount by doing this "free - give it to page allocator - reserve
| again" dancing.  We should just allocate regions aligned to page
| boundaries and free them later when memblock is no longer in use.

in that case, when DEBUG_PAGEALLOC, will get panic:

     memblock_free: [0x0000102febc080-0x0000102febf080] memblock_free_reserved_regions+0x37/0x39
  BUG: unable to handle kernel paging request at ffff88102febd948
  IP: [<ffffffff836a5774>] __next_free_mem_range+0x9b/0x155
  PGD 4826063 PUD cf67a067 PMD cf7fa067 PTE 800000102febd160
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  CPU 0
  Pid: 0, comm: swapper Not tainted 3.5.0-rc2-next-20120614-sasha #447
  RIP: 0010:[<ffffffff836a5774>]  [<ffffffff836a5774>] __next_free_mem_range+0x9b/0x155

See the discussion at https://lkml.org/lkml/2012/6/13/469

So try to allocate with PAGE_SIZE alignment and free it later.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16 09:04:45 -07:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
asm-generic thp: avoid atomic64_read in pmd_read_atomic for 32bit PAE 2012-07-16 09:04:42 -07:00
crypto crypto: user - Fix lookup of algorithms with IV generator 2012-03-29 19:52:47 +08:00
drm drm/radeon/kms: add new SI PCI ids 2012-06-10 00:36:18 +09:00
keys
linux memblock: free allocated memblock_reserved_regions later 2012-07-16 09:04:45 -07:00
math-emu
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-14 11:23:37 -07:00
misc
mtd
net bonding: Fix corrupted queue_mapping 2012-07-16 09:03:47 -07:00
pcmcia
rdma
rxrpc
scsi SCSI: libsas: fix taskfile corruption in sas_ata_qc_fill_rtf 2012-07-16 09:04:37 -07:00
sound ALSA: hda - hide HDMI/ELD printks unless snd.debug=2 2012-04-10 14:53:55 +02:00
target
trace Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-04-04 10:04:42 -07:00
video Merge branch 'platforms' of git://git.linaro.org/people/rmk/linux-arm 2012-03-27 18:17:02 -07:00
xen xen: do not map the same GSI twice in PVHVM guests. 2012-06-01 15:18:25 +08:00
Kbuild