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author | Yinghai Lu <yinghai@kernel.org> | 2012-07-11 14:02:56 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-16 09:04:45 -0700 |
commit | 7ad71f960f0f6e06cbded278809674afc515036a (patch) | |
tree | df62cd2fb579dc1ded7ec28c669ed03bf506ffe9 /fs/nfs/iostat.h | |
parent | 0fa627b15c842095b5147f381fa1943a6a46bb01 (diff) |
memblock: free allocated memblock_reserved_regions later
commit 29f6738609e40227dabcc63bfb3b84b3726a75bd 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>
Diffstat (limited to 'fs/nfs/iostat.h')
0 files changed, 0 insertions, 0 deletions