2005-04-17 06:20:36 +08:00
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#ifndef _LINUX_HUGETLB_H
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#define _LINUX_HUGETLB_H
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2011-05-27 03:03:50 +08:00
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#include <linux/mm_types.h>
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2007-07-30 06:36:13 +08:00
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#include <linux/fs.h>
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2010-05-28 08:29:15 +08:00
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#include <linux/hugetlb_inline.h>
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2012-08-01 07:42:24 +08:00
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#include <linux/cgroup.h>
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2007-07-30 06:36:13 +08:00
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2009-09-25 05:47:45 +08:00
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struct ctl_table;
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struct user_struct;
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2012-08-01 07:42:03 +08:00
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struct mmu_gather;
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2009-09-25 05:47:45 +08:00
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2005-04-17 06:20:36 +08:00
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#ifdef CONFIG_HUGETLB_PAGE
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#include <linux/mempolicy.h>
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2007-03-02 07:46:08 +08:00
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#include <linux/shm.h>
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2005-06-22 08:14:44 +08:00
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#include <asm/tlbflush.h>
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2005-04-17 06:20:36 +08:00
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hugepages: fix use after free bug in "quota" handling
hugetlbfs_{get,put}_quota() are badly named. They don't interact with the
general quota handling code, and they don't much resemble its behaviour.
Rather than being about maintaining limits on on-disk block usage by
particular users, they are instead about maintaining limits on in-memory
page usage (including anonymous MAP_PRIVATE copied-on-write pages)
associated with a particular hugetlbfs filesystem instance.
Worse, they work by having callbacks to the hugetlbfs filesystem code from
the low-level page handling code, in particular from free_huge_page().
This is a layering violation of itself, but more importantly, if the
kernel does a get_user_pages() on hugepages (which can happen from KVM
amongst others), then the free_huge_page() can be delayed until after the
associated inode has already been freed. If an unmount occurs at the
wrong time, even the hugetlbfs superblock where the "quota" limits are
stored may have been freed.
Andrew Barry proposed a patch to fix this by having hugepages, instead of
storing a pointer to their address_space and reaching the superblock from
there, had the hugepages store pointers directly to the superblock,
bumping the reference count as appropriate to avoid it being freed.
Andrew Morton rejected that version, however, on the grounds that it made
the existing layering violation worse.
This is a reworked version of Andrew's patch, which removes the extra, and
some of the existing, layering violation. It works by introducing the
concept of a hugepage "subpool" at the lower hugepage mm layer - that is a
finite logical pool of hugepages to allocate from. hugetlbfs now creates
a subpool for each filesystem instance with a page limit set, and a
pointer to the subpool gets added to each allocated hugepage, instead of
the address_space pointer used now. The subpool has its own lifetime and
is only freed once all pages in it _and_ all other references to it (i.e.
superblocks) are gone.
subpools are optional - a NULL subpool pointer is taken by the code to
mean that no subpool limits are in effect.
Previous discussion of this bug found in: "Fix refcounting in hugetlbfs
quota handling.". See: https://lkml.org/lkml/2011/8/11/28 or
http://marc.info/?l=linux-mm&m=126928970510627&w=1
v2: Fixed a bug spotted by Hillf Danton, and removed the extra parameter to
alloc_huge_page() - since it already takes the vma, it is not necessary.
Signed-off-by: Andrew Barry <abarry@cray.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-22 07:34:12 +08:00
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struct hugepage_subpool {
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spinlock_t lock;
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long count;
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long max_hpages, used_hpages;
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};
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2012-08-01 07:42:10 +08:00
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extern spinlock_t hugetlb_lock;
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extern int hugetlb_max_hstate __read_mostly;
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#define for_each_hstate(h) \
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for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++)
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hugepages: fix use after free bug in "quota" handling
hugetlbfs_{get,put}_quota() are badly named. They don't interact with the
general quota handling code, and they don't much resemble its behaviour.
Rather than being about maintaining limits on on-disk block usage by
particular users, they are instead about maintaining limits on in-memory
page usage (including anonymous MAP_PRIVATE copied-on-write pages)
associated with a particular hugetlbfs filesystem instance.
Worse, they work by having callbacks to the hugetlbfs filesystem code from
the low-level page handling code, in particular from free_huge_page().
This is a layering violation of itself, but more importantly, if the
kernel does a get_user_pages() on hugepages (which can happen from KVM
amongst others), then the free_huge_page() can be delayed until after the
associated inode has already been freed. If an unmount occurs at the
wrong time, even the hugetlbfs superblock where the "quota" limits are
stored may have been freed.
Andrew Barry proposed a patch to fix this by having hugepages, instead of
storing a pointer to their address_space and reaching the superblock from
there, had the hugepages store pointers directly to the superblock,
bumping the reference count as appropriate to avoid it being freed.
Andrew Morton rejected that version, however, on the grounds that it made
the existing layering violation worse.
This is a reworked version of Andrew's patch, which removes the extra, and
some of the existing, layering violation. It works by introducing the
concept of a hugepage "subpool" at the lower hugepage mm layer - that is a
finite logical pool of hugepages to allocate from. hugetlbfs now creates
a subpool for each filesystem instance with a page limit set, and a
pointer to the subpool gets added to each allocated hugepage, instead of
the address_space pointer used now. The subpool has its own lifetime and
is only freed once all pages in it _and_ all other references to it (i.e.
superblocks) are gone.
subpools are optional - a NULL subpool pointer is taken by the code to
mean that no subpool limits are in effect.
Previous discussion of this bug found in: "Fix refcounting in hugetlbfs
quota handling.". See: https://lkml.org/lkml/2011/8/11/28 or
http://marc.info/?l=linux-mm&m=126928970510627&w=1
v2: Fixed a bug spotted by Hillf Danton, and removed the extra parameter to
alloc_huge_page() - since it already takes the vma, it is not necessary.
Signed-off-by: Andrew Barry <abarry@cray.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-22 07:34:12 +08:00
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struct hugepage_subpool *hugepage_new_subpool(long nr_blocks);
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void hugepage_put_subpool(struct hugepage_subpool *spool);
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mm: introduce PageHuge() for testing huge/gigantic pages
A series of patches to enhance the /proc/pagemap interface and to add a
userspace executable which can be used to present the pagemap data.
Export 10 more flags to end users (and more for kernel developers):
11. KPF_MMAP (pseudo flag) memory mapped page
12. KPF_ANON (pseudo flag) memory mapped page (anonymous)
13. KPF_SWAPCACHE page is in swap cache
14. KPF_SWAPBACKED page is swap/RAM backed
15. KPF_COMPOUND_HEAD (*)
16. KPF_COMPOUND_TAIL (*)
17. KPF_HUGE hugeTLB pages
18. KPF_UNEVICTABLE page is in the unevictable LRU list
19. KPF_HWPOISON hardware detected corruption
20. KPF_NOPAGE (pseudo flag) no page frame at the address
(*) For compound pages, exporting _both_ head/tail info enables
users to tell where a compound page starts/ends, and its order.
a simple demo of the page-types tool
# ./page-types -h
page-types [options]
-r|--raw Raw mode, for kernel developers
-a|--addr addr-spec Walk a range of pages
-b|--bits bits-spec Walk pages with specified bits
-l|--list Show page details in ranges
-L|--list-each Show page details one by one
-N|--no-summary Don't show summay info
-h|--help Show this usage message
addr-spec:
N one page at offset N (unit: pages)
N+M pages range from N to N+M-1
N,M pages range from N to M-1
N, pages range from N to end
,M pages range from 0 to M
bits-spec:
bit1,bit2 (flags & (bit1|bit2)) != 0
bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1
bit1,~bit2 (flags & (bit1|bit2)) == bit1
=bit1,bit2 flags == (bit1|bit2)
bit-names:
locked error referenced uptodate
dirty lru active slab
writeback reclaim buddy mmap
anonymous swapcache swapbacked compound_head
compound_tail huge unevictable hwpoison
nopage reserved(r) mlocked(r) mappedtodisk(r)
private(r) private_2(r) owner_private(r) arch(r)
uncached(r) readahead(o) slob_free(o) slub_frozen(o)
slub_debug(o)
(r) raw mode bits (o) overloaded bits
# ./page-types
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 487369 1903 _________________________________
0x0000000000000014 5 0 __R_D____________________________ referenced,dirty
0x0000000000000020 1 0 _____l___________________________ lru
0x0000000000000024 34 0 __R__l___________________________ referenced,lru
0x0000000000000028 3838 14 ___U_l___________________________ uptodate,lru
0x0001000000000028 48 0 ___U_l_______________________I___ uptodate,lru,readahead
0x000000000000002c 6478 25 __RU_l___________________________ referenced,uptodate,lru
0x000100000000002c 47 0 __RU_l_______________________I___ referenced,uptodate,lru,readahead
0x0000000000000040 8344 32 ______A__________________________ active
0x0000000000000060 1 0 _____lA__________________________ lru,active
0x0000000000000068 348 1 ___U_lA__________________________ uptodate,lru,active
0x0001000000000068 12 0 ___U_lA______________________I___ uptodate,lru,active,readahead
0x000000000000006c 988 3 __RU_lA__________________________ referenced,uptodate,lru,active
0x000100000000006c 48 0 __RU_lA______________________I___ referenced,uptodate,lru,active,readahead
0x0000000000004078 1 0 ___UDlA_______b__________________ uptodate,dirty,lru,active,swapbacked
0x000000000000407c 34 0 __RUDlA_______b__________________ referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400 503 1 __________B______________________ buddy
0x0000000000000804 1 0 __R________M_____________________ referenced,mmap
0x0000000000000828 1029 4 ___U_l_____M_____________________ uptodate,lru,mmap
0x0001000000000828 43 0 ___U_l_____M_________________I___ uptodate,lru,mmap,readahead
0x000000000000082c 382 1 __RU_l_____M_____________________ referenced,uptodate,lru,mmap
0x000100000000082c 12 0 __RU_l_____M_________________I___ referenced,uptodate,lru,mmap,readahead
0x0000000000000868 192 0 ___U_lA____M_____________________ uptodate,lru,active,mmap
0x0001000000000868 12 0 ___U_lA____M_________________I___ uptodate,lru,active,mmap,readahead
0x000000000000086c 800 3 __RU_lA____M_____________________ referenced,uptodate,lru,active,mmap
0x000100000000086c 31 0 __RU_lA____M_________________I___ referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878 2 0 ___UDlA____M__b__________________ uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000 492 1 ____________a____________________ anonymous
0x0000000000005808 4 0 ___U_______Ma_b__________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868 2839 11 ___U_lA____Ma_b__________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 30 0 __RU_lA____Ma_b__________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 513968 2007
# ./page-types -r
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 468002 1828 _________________________________
0x0000000100000000 19102 74 _____________________r___________ reserved
0x0000000000008000 41 0 _______________H_________________ compound_head
0x0000000000010000 188 0 ________________T________________ compound_tail
0x0000000000008014 1 0 __R_D__________H_________________ referenced,dirty,compound_head
0x0000000000010014 4 0 __R_D___________T________________ referenced,dirty,compound_tail
0x0000000000000020 1 0 _____l___________________________ lru
0x0000000800000024 34 0 __R__l__________________P________ referenced,lru,private
0x0000000000000028 3794 14 ___U_l___________________________ uptodate,lru
0x0001000000000028 46 0 ___U_l_______________________I___ uptodate,lru,readahead
0x0000000400000028 44 0 ___U_l_________________d_________ uptodate,lru,mappedtodisk
0x0001000400000028 2 0 ___U_l_________________d_____I___ uptodate,lru,mappedtodisk,readahead
0x000000000000002c 6434 25 __RU_l___________________________ referenced,uptodate,lru
0x000100000000002c 47 0 __RU_l_______________________I___ referenced,uptodate,lru,readahead
0x000000040000002c 14 0 __RU_l_________________d_________ referenced,uptodate,lru,mappedtodisk
0x000000080000002c 30 0 __RU_l__________________P________ referenced,uptodate,lru,private
0x0000000800000040 8124 31 ______A_________________P________ active,private
0x0000000000000040 219 0 ______A__________________________ active
0x0000000800000060 1 0 _____lA_________________P________ lru,active,private
0x0000000000000068 322 1 ___U_lA__________________________ uptodate,lru,active
0x0001000000000068 12 0 ___U_lA______________________I___ uptodate,lru,active,readahead
0x0000000400000068 13 0 ___U_lA________________d_________ uptodate,lru,active,mappedtodisk
0x0000000800000068 12 0 ___U_lA_________________P________ uptodate,lru,active,private
0x000000000000006c 977 3 __RU_lA__________________________ referenced,uptodate,lru,active
0x000100000000006c 48 0 __RU_lA______________________I___ referenced,uptodate,lru,active,readahead
0x000000040000006c 5 0 __RU_lA________________d_________ referenced,uptodate,lru,active,mappedtodisk
0x000000080000006c 3 0 __RU_lA_________________P________ referenced,uptodate,lru,active,private
0x0000000c0000006c 3 0 __RU_lA________________dP________ referenced,uptodate,lru,active,mappedtodisk,private
0x0000000c00000068 1 0 ___U_lA________________dP________ uptodate,lru,active,mappedtodisk,private
0x0000000000004078 1 0 ___UDlA_______b__________________ uptodate,dirty,lru,active,swapbacked
0x000000000000407c 34 0 __RUDlA_______b__________________ referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400 538 2 __________B______________________ buddy
0x0000000000000804 1 0 __R________M_____________________ referenced,mmap
0x0000000000000828 1029 4 ___U_l_____M_____________________ uptodate,lru,mmap
0x0001000000000828 43 0 ___U_l_____M_________________I___ uptodate,lru,mmap,readahead
0x000000000000082c 382 1 __RU_l_____M_____________________ referenced,uptodate,lru,mmap
0x000100000000082c 12 0 __RU_l_____M_________________I___ referenced,uptodate,lru,mmap,readahead
0x0000000000000868 192 0 ___U_lA____M_____________________ uptodate,lru,active,mmap
0x0001000000000868 12 0 ___U_lA____M_________________I___ uptodate,lru,active,mmap,readahead
0x000000000000086c 800 3 __RU_lA____M_____________________ referenced,uptodate,lru,active,mmap
0x000100000000086c 31 0 __RU_lA____M_________________I___ referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878 2 0 ___UDlA____M__b__________________ uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000 492 1 ____________a____________________ anonymous
0x0000000000005008 2 0 ___U________a_b__________________ uptodate,anonymous,swapbacked
0x0000000000005808 4 0 ___U_______Ma_b__________________ uptodate,mmap,anonymous,swapbacked
0x000000000000580c 1 0 __RU_______Ma_b__________________ referenced,uptodate,mmap,anonymous,swapbacked
0x0000000000005868 2839 11 ___U_lA____Ma_b__________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 29 0 __RU_lA____Ma_b__________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 513968 2007
# ./page-types --raw --list --no-summary --bits reserved
offset count flags
0 15 _____________________r___________
31 4 _____________________r___________
159 97 _____________________r___________
4096 2067 _____________________r___________
6752 2390 _____________________r___________
9355 3 _____________________r___________
9728 14526 _____________________r___________
This patch:
Introduce PageHuge(), which identifies huge/gigantic pages by their
dedicated compound destructor functions.
Also move prep_compound_gigantic_page() to hugetlb.c and make
__free_pages_ok() non-static.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-17 06:32:22 +08:00
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int PageHuge(struct page *page);
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2008-07-24 12:27:23 +08:00
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void reset_vma_resv_huge_pages(struct vm_area_struct *vma);
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2009-09-24 06:57:19 +08:00
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int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
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int hugetlb_overcommit_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
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int hugetlb_treat_movable_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
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hugetlb: derive huge pages nodes allowed from task mempolicy
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 <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 09:58:21 +08:00
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#ifdef CONFIG_NUMA
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int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int,
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void __user *, size_t *, loff_t *);
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#endif
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2005-04-17 06:20:36 +08:00
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int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
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2013-02-23 08:35:55 +08:00
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long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
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struct page **, struct vm_area_struct **,
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unsigned long *, unsigned long *, long, unsigned int);
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hugetlb: guarantee that COW faults for a process that called mmap(MAP_PRIVATE) on hugetlbfs will succeed
After patch 2 in this series, a process that successfully calls mmap() for
a MAP_PRIVATE mapping will be guaranteed to successfully fault until a
process calls fork(). At that point, the next write fault from the parent
could fail due to COW if the child still has a reference.
We only reserve pages for the parent but a copy must be made to avoid
leaking data from the parent to the child after fork(). Reserves could be
taken for both parent and child at fork time to guarantee faults but if
the mapping is large it is highly likely we will not have sufficient pages
for the reservation, and it is common to fork only to exec() immediatly
after. A failure here would be very undesirable.
Note that the current behaviour of mainline with MAP_PRIVATE pages is
pretty bad. The following situation is allowed to occur today.
1. Process calls mmap(MAP_PRIVATE)
2. Process calls mlock() to fault all pages and makes sure it succeeds
3. Process forks()
4. Process writes to MAP_PRIVATE mapping while child still exists
5. If the COW fails at this point, the process gets SIGKILLed even though it
had taken care to ensure the pages existed
This patch improves the situation by guaranteeing the reliability of the
process that successfully calls mmap(). When the parent performs COW, it
will try to satisfy the allocation without using reserves. If that fails
the parent will steal the page leaving any children without a page.
Faults from the child after that point will result in failure. If the
child COW happens first, an attempt will be made to allocate the page
without reserves and the child will get SIGKILLed on failure.
To summarise the new behaviour:
1. If the original mapper performs COW on a private mapping with multiple
references, it will attempt to allocate a hugepage from the pool or
the buddy allocator without using the existing reserves. On fail, VMAs
mapping the same area are traversed and the page being COW'd is unmapped
where found. It will then steal the original page as the last mapper in
the normal way.
2. The VMAs the pages were unmapped from are flagged to note that pages
with data no longer exist. Future no-page faults on those VMAs will
terminate the process as otherwise it would appear that data was corrupted.
A warning is printed to the console that this situation occured.
2. If the child performs COW first, it will attempt to satisfy the COW
from the pool if there are enough pages or via the buddy allocator if
overcommit is allowed and the buddy allocator can satisfy the request. If
it fails, the child will be killed.
If the pool is large enough, existing applications will not notice that
the reserves were a factor. Existing applications depending on the
no-reserves been set are unlikely to exist as for much of the history of
hugetlbfs, pages were prefaulted at mmap(), allocating the pages at that
point or failing the mmap().
[npiggin@suse.de: fix CONFIG_HUGETLB=n build]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 12:27:25 +08:00
|
|
|
void unmap_hugepage_range(struct vm_area_struct *,
|
2012-08-01 07:42:03 +08:00
|
|
|
unsigned long, unsigned long, struct page *);
|
mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
If a process creates a large hugetlbfs mapping that is eligible for page
table sharing and forks heavily with children some of whom fault and
others which destroy the mapping then it is possible for page tables to
get corrupted. Some teardowns of the mapping encounter a "bad pmd" and
output a message to the kernel log. The final teardown will trigger a
BUG_ON in mm/filemap.c.
This was reproduced in 3.4 but is known to have existed for a long time
and goes back at least as far as 2.6.37. It was probably was introduced
in 2.6.20 by [39dde65c: shared page table for hugetlb page]. The messages
look like this;
[ ..........] Lots of bad pmd messages followed by this
[ 127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7).
[ 127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7).
[ 127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7).
[ 127.186778] ------------[ cut here ]------------
[ 127.186781] kernel BUG at mm/filemap.c:134!
[ 127.186782] invalid opcode: 0000 [#1] SMP
[ 127.186783] CPU 7
[ 127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod
[ 127.186801]
[ 127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR
[ 127.186804] RIP: 0010:[<ffffffff810ed6ce>] [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[ 127.186809] RSP: 0000:ffff8804144b5c08 EFLAGS: 00010002
[ 127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0
[ 127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00
[ 127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003
[ 127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8
[ 127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8
[ 127.186815] FS: 00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
[ 127.186816] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0
[ 127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0)
[ 127.186821] Stack:
[ 127.186822] ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b
[ 127.186824] ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98
[ 127.186825] ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000
[ 127.186827] Call Trace:
[ 127.186829] [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80
[ 127.186832] [<ffffffff811bc925>] truncate_hugepages+0x115/0x220
[ 127.186834] [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30
[ 127.186837] [<ffffffff811655c7>] evict+0xa7/0x1b0
[ 127.186839] [<ffffffff811657a3>] iput_final+0xd3/0x1f0
[ 127.186840] [<ffffffff811658f9>] iput+0x39/0x50
[ 127.186842] [<ffffffff81162708>] d_kill+0xf8/0x130
[ 127.186843] [<ffffffff81162812>] dput+0xd2/0x1a0
[ 127.186845] [<ffffffff8114e2d0>] __fput+0x170/0x230
[ 127.186848] [<ffffffff81236e0e>] ? rb_erase+0xce/0x150
[ 127.186849] [<ffffffff8114e3ad>] fput+0x1d/0x30
[ 127.186851] [<ffffffff81117db7>] remove_vma+0x37/0x80
[ 127.186853] [<ffffffff81119182>] do_munmap+0x2d2/0x360
[ 127.186855] [<ffffffff811cc639>] sys_shmdt+0xc9/0x170
[ 127.186857] [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b
[ 127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0
[ 127.186868] RIP [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[ 127.186870] RSP <ffff8804144b5c08>
[ 127.186871] ---[ end trace 7cbac5d1db69f426 ]---
The bug is a race and not always easy to reproduce. To reproduce it I was
doing the following on a single socket I7-based machine with 16G of RAM.
$ hugeadm --pool-pages-max DEFAULT:13G
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall
$ for i in `seq 1 9000`; do ./hugetlbfs-test; done
On my particular machine, it usually triggers within 10 minutes but
enabling debug options can change the timing such that it never hits.
Once the bug is triggered, the machine is in trouble and needs to be
rebooted. The machine will respond but processes accessing proc like "ps
aux" will hang due to the BUG_ON. shutdown will also hang and needs a
hard reset or a sysrq-b.
The basic problem is a race between page table sharing and teardown. For
the most part page table sharing depends on i_mmap_mutex. In some cases,
it is also taking the mm->page_table_lock for the PTE updates but with
shared page tables, it is the i_mmap_mutex that is more important.
Unfortunately it appears to be also insufficient. Consider the following
situation
Process A Process B
--------- ---------
hugetlb_fault shmdt
LockWrite(mmap_sem)
do_munmap
unmap_region
unmap_vmas
unmap_single_vma
unmap_hugepage_range
Lock(i_mmap_mutex)
Lock(mm->page_table_lock)
huge_pmd_unshare/unmap tables <--- (1)
Unlock(mm->page_table_lock)
Unlock(i_mmap_mutex)
huge_pte_alloc ...
Lock(i_mmap_mutex) ...
vma_prio_walk, find svma, spte ...
Lock(mm->page_table_lock) ...
share spte ...
Unlock(mm->page_table_lock) ...
Unlock(i_mmap_mutex) ...
hugetlb_no_page <--- (2)
free_pgtables
unlink_file_vma
hugetlb_free_pgd_range
remove_vma_list
In this scenario, it is possible for Process A to share page tables with
Process B that is trying to tear them down. The i_mmap_mutex on its own
does not prevent Process A walking Process B's page tables. At (1) above,
the page tables are not shared yet so it unmaps the PMDs. Process A sets
up page table sharing and at (2) faults a new entry. Process B then trips
up on it in free_pgtables.
This patch fixes the problem by adding a new function
__unmap_hugepage_range_final that is only called when the VMA is about to
be destroyed. This function clears VM_MAYSHARE during
unmap_hugepage_range() under the i_mmap_mutex. This makes the VMA
ineligible for sharing and avoids the race. Superficially this looks like
it would then be vunerable to truncate and madvise issues but hugetlbfs
has its own truncate handlers so does not use unmap_mapping_range() and
does not support madvise(DONTNEED).
This should be treated as a -stable candidate if it is merged.
Test program is as follows. The test case was mostly written by Michal
Hocko with a few minor changes to reproduce this bug.
==== CUT HERE ====
static size_t huge_page_size = (2UL << 20);
static size_t nr_huge_page_A = 512;
static size_t nr_huge_page_B = 5632;
unsigned int get_random(unsigned int max)
{
struct timeval tv;
gettimeofday(&tv, NULL);
srandom(tv.tv_usec);
return random() % max;
}
static void play(void *addr, size_t size)
{
unsigned char *start = addr,
*end = start + size,
*a;
start += get_random(size/2);
/* we could itterate on huge pages but let's give it more time. */
for (a = start; a < end; a += 4096)
*a = 0;
}
int main(int argc, char **argv)
{
key_t key = IPC_PRIVATE;
size_t sizeA = nr_huge_page_A * huge_page_size;
size_t sizeB = nr_huge_page_B * huge_page_size;
int shmidA, shmidB;
void *addrA = NULL, *addrB = NULL;
int nr_children = 300, n = 0;
if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
perror("shmget:");
return 1;
}
if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) {
perror("shmat");
return 1;
}
if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
perror("shmget:");
return 1;
}
if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) {
perror("shmat");
return 1;
}
fork_child:
switch(fork()) {
case 0:
switch (n%3) {
case 0:
play(addrA, sizeA);
break;
case 1:
play(addrB, sizeB);
break;
case 2:
break;
}
break;
case -1:
perror("fork:");
break;
default:
if (++n < nr_children)
goto fork_child;
play(addrA, sizeA);
break;
}
shmdt(addrA);
shmdt(addrB);
do {
wait(NULL);
} while (--n > 0);
shmctl(shmidA, IPC_RMID, NULL);
shmctl(shmidB, IPC_RMID, NULL);
return 0;
}
[akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:46:20 +08:00
|
|
|
void __unmap_hugepage_range_final(struct mmu_gather *tlb,
|
|
|
|
|
struct vm_area_struct *vma,
|
|
|
|
|
unsigned long start, unsigned long end,
|
|
|
|
|
struct page *ref_page);
|
2012-08-01 07:42:03 +08:00
|
|
|
void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
|
|
|
|
|
unsigned long start, unsigned long end,
|
|
|
|
|
struct page *ref_page);
|
2008-10-16 03:50:22 +08:00
|
|
|
void hugetlb_report_meminfo(struct seq_file *);
|
2005-04-17 06:20:36 +08:00
|
|
|
int hugetlb_report_node_meminfo(int, char *);
|
2013-04-30 06:07:48 +08:00
|
|
|
void hugetlb_show_meminfo(void);
|
2005-04-17 06:20:36 +08:00
|
|
|
unsigned long hugetlb_total_pages(void);
|
2005-10-20 23:24:28 +08:00
|
|
|
int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
|
2009-06-23 20:49:05 +08:00
|
|
|
unsigned long address, unsigned int flags);
|
2008-07-24 12:27:23 +08:00
|
|
|
int hugetlb_reserve_pages(struct inode *inode, long from, long to,
|
2009-02-10 22:02:27 +08:00
|
|
|
struct vm_area_struct *vma,
|
2011-05-26 18:16:19 +08:00
|
|
|
vm_flags_t vm_flags);
|
2006-06-23 17:03:15 +08:00
|
|
|
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
|
2010-09-08 09:19:36 +08:00
|
|
|
int dequeue_hwpoisoned_huge_page(struct page *page);
|
mm: migrate: make core migration code aware of hugepage
Currently hugepage migration is available only for soft offlining, but
it's also useful for some other users of page migration (clearly because
users of hugepage can enjoy the benefit of mempolicy and memory hotplug.)
So this patchset tries to extend such users to support hugepage migration.
The target of this patchset is to enable hugepage migration for NUMA
related system calls (migrate_pages(2), move_pages(2), and mbind(2)), and
memory hotplug.
This patchset does not add hugepage migration for memory compaction,
because users of memory compaction mainly expect to construct thp by
arranging raw pages, and there's little or no need to compact hugepages.
CMA, another user of page migration, can have benefit from hugepage
migration, but is not enabled to support it for now (just because of lack
of testing and expertise in CMA.)
Hugepage migration of non pmd-based hugepage (for example 1GB hugepage in
x86_64, or hugepages in architectures like ia64) is not enabled for now
(again, because of lack of testing.)
As for how these are achived, I extended the API (migrate_pages()) to
handle hugepage (with patch 1 and 2) and adjusted code of each caller to
check and collect movable hugepages (with patch 3-7). Remaining 2 patches
are kind of miscellaneous ones to avoid unexpected behavior. Patch 8 is
about making sure that we only migrate pmd-based hugepages. And patch 9
is about choosing appropriate zone for hugepage allocation.
My test is mainly functional one, simply kicking hugepage migration via
each entry point and confirm that migration is done correctly. Test code
is available here:
git://github.com/Naoya-Horiguchi/test_hugepage_migration_extension.git
And I always run libhugetlbfs test when changing hugetlbfs's code. With
this patchset, no regression was found in the test.
This patch (of 9):
Before enabling each user of page migration to support hugepage,
this patch enables the list of pages for migration to link not only
LRU pages, but also hugepages. As a result, putback_movable_pages()
and migrate_pages() can handle both of LRU pages and hugepages.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 05:21:59 +08:00
|
|
|
bool isolate_huge_page(struct page *page, struct list_head *list);
|
|
|
|
|
void putback_active_hugepage(struct page *page);
|
2010-09-08 09:19:34 +08:00
|
|
|
void copy_huge_page(struct page *dst, struct page *src);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2013-04-23 19:35:02 +08:00
|
|
|
#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
|
|
|
|
|
pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
|
|
|
|
|
#endif
|
|
|
|
|
|
2007-07-17 19:03:13 +08:00
|
|
|
extern unsigned long hugepages_treat_as_movable;
|
2005-04-17 06:20:36 +08:00
|
|
|
extern const unsigned long hugetlb_zero, hugetlb_infinity;
|
|
|
|
|
extern int sysctl_hugetlb_shm_group;
|
2008-07-24 12:27:52 +08:00
|
|
|
extern struct list_head huge_boot_pages;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2005-06-22 08:14:44 +08:00
|
|
|
/* arch callbacks */
|
|
|
|
|
|
2008-07-24 12:27:41 +08:00
|
|
|
pte_t *huge_pte_alloc(struct mm_struct *mm,
|
|
|
|
|
unsigned long addr, unsigned long sz);
|
2005-06-22 08:14:44 +08:00
|
|
|
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
|
2006-12-07 12:32:03 +08:00
|
|
|
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
|
2005-06-22 08:14:44 +08:00
|
|
|
struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
|
|
|
|
|
int write);
|
|
|
|
|
struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
|
|
|
pmd_t *pmd, int write);
|
2008-07-24 12:27:50 +08:00
|
|
|
struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
|
|
|
|
|
pud_t *pud, int write);
|
2005-06-22 08:14:44 +08:00
|
|
|
int pmd_huge(pmd_t pmd);
|
2008-07-24 12:27:50 +08:00
|
|
|
int pud_huge(pud_t pmd);
|
2012-11-19 10:14:23 +08:00
|
|
|
unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
|
2006-03-22 16:08:50 +08:00
|
|
|
unsigned long address, unsigned long end, pgprot_t newprot);
|
2005-06-22 08:14:44 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#else /* !CONFIG_HUGETLB_PAGE */
|
|
|
|
|
|
mm: introduce PageHuge() for testing huge/gigantic pages
A series of patches to enhance the /proc/pagemap interface and to add a
userspace executable which can be used to present the pagemap data.
Export 10 more flags to end users (and more for kernel developers):
11. KPF_MMAP (pseudo flag) memory mapped page
12. KPF_ANON (pseudo flag) memory mapped page (anonymous)
13. KPF_SWAPCACHE page is in swap cache
14. KPF_SWAPBACKED page is swap/RAM backed
15. KPF_COMPOUND_HEAD (*)
16. KPF_COMPOUND_TAIL (*)
17. KPF_HUGE hugeTLB pages
18. KPF_UNEVICTABLE page is in the unevictable LRU list
19. KPF_HWPOISON hardware detected corruption
20. KPF_NOPAGE (pseudo flag) no page frame at the address
(*) For compound pages, exporting _both_ head/tail info enables
users to tell where a compound page starts/ends, and its order.
a simple demo of the page-types tool
# ./page-types -h
page-types [options]
-r|--raw Raw mode, for kernel developers
-a|--addr addr-spec Walk a range of pages
-b|--bits bits-spec Walk pages with specified bits
-l|--list Show page details in ranges
-L|--list-each Show page details one by one
-N|--no-summary Don't show summay info
-h|--help Show this usage message
addr-spec:
N one page at offset N (unit: pages)
N+M pages range from N to N+M-1
N,M pages range from N to M-1
N, pages range from N to end
,M pages range from 0 to M
bits-spec:
bit1,bit2 (flags & (bit1|bit2)) != 0
bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1
bit1,~bit2 (flags & (bit1|bit2)) == bit1
=bit1,bit2 flags == (bit1|bit2)
bit-names:
locked error referenced uptodate
dirty lru active slab
writeback reclaim buddy mmap
anonymous swapcache swapbacked compound_head
compound_tail huge unevictable hwpoison
nopage reserved(r) mlocked(r) mappedtodisk(r)
private(r) private_2(r) owner_private(r) arch(r)
uncached(r) readahead(o) slob_free(o) slub_frozen(o)
slub_debug(o)
(r) raw mode bits (o) overloaded bits
# ./page-types
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 487369 1903 _________________________________
0x0000000000000014 5 0 __R_D____________________________ referenced,dirty
0x0000000000000020 1 0 _____l___________________________ lru
0x0000000000000024 34 0 __R__l___________________________ referenced,lru
0x0000000000000028 3838 14 ___U_l___________________________ uptodate,lru
0x0001000000000028 48 0 ___U_l_______________________I___ uptodate,lru,readahead
0x000000000000002c 6478 25 __RU_l___________________________ referenced,uptodate,lru
0x000100000000002c 47 0 __RU_l_______________________I___ referenced,uptodate,lru,readahead
0x0000000000000040 8344 32 ______A__________________________ active
0x0000000000000060 1 0 _____lA__________________________ lru,active
0x0000000000000068 348 1 ___U_lA__________________________ uptodate,lru,active
0x0001000000000068 12 0 ___U_lA______________________I___ uptodate,lru,active,readahead
0x000000000000006c 988 3 __RU_lA__________________________ referenced,uptodate,lru,active
0x000100000000006c 48 0 __RU_lA______________________I___ referenced,uptodate,lru,active,readahead
0x0000000000004078 1 0 ___UDlA_______b__________________ uptodate,dirty,lru,active,swapbacked
0x000000000000407c 34 0 __RUDlA_______b__________________ referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400 503 1 __________B______________________ buddy
0x0000000000000804 1 0 __R________M_____________________ referenced,mmap
0x0000000000000828 1029 4 ___U_l_____M_____________________ uptodate,lru,mmap
0x0001000000000828 43 0 ___U_l_____M_________________I___ uptodate,lru,mmap,readahead
0x000000000000082c 382 1 __RU_l_____M_____________________ referenced,uptodate,lru,mmap
0x000100000000082c 12 0 __RU_l_____M_________________I___ referenced,uptodate,lru,mmap,readahead
0x0000000000000868 192 0 ___U_lA____M_____________________ uptodate,lru,active,mmap
0x0001000000000868 12 0 ___U_lA____M_________________I___ uptodate,lru,active,mmap,readahead
0x000000000000086c 800 3 __RU_lA____M_____________________ referenced,uptodate,lru,active,mmap
0x000100000000086c 31 0 __RU_lA____M_________________I___ referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878 2 0 ___UDlA____M__b__________________ uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000 492 1 ____________a____________________ anonymous
0x0000000000005808 4 0 ___U_______Ma_b__________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868 2839 11 ___U_lA____Ma_b__________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 30 0 __RU_lA____Ma_b__________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 513968 2007
# ./page-types -r
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 468002 1828 _________________________________
0x0000000100000000 19102 74 _____________________r___________ reserved
0x0000000000008000 41 0 _______________H_________________ compound_head
0x0000000000010000 188 0 ________________T________________ compound_tail
0x0000000000008014 1 0 __R_D__________H_________________ referenced,dirty,compound_head
0x0000000000010014 4 0 __R_D___________T________________ referenced,dirty,compound_tail
0x0000000000000020 1 0 _____l___________________________ lru
0x0000000800000024 34 0 __R__l__________________P________ referenced,lru,private
0x0000000000000028 3794 14 ___U_l___________________________ uptodate,lru
0x0001000000000028 46 0 ___U_l_______________________I___ uptodate,lru,readahead
0x0000000400000028 44 0 ___U_l_________________d_________ uptodate,lru,mappedtodisk
0x0001000400000028 2 0 ___U_l_________________d_____I___ uptodate,lru,mappedtodisk,readahead
0x000000000000002c 6434 25 __RU_l___________________________ referenced,uptodate,lru
0x000100000000002c 47 0 __RU_l_______________________I___ referenced,uptodate,lru,readahead
0x000000040000002c 14 0 __RU_l_________________d_________ referenced,uptodate,lru,mappedtodisk
0x000000080000002c 30 0 __RU_l__________________P________ referenced,uptodate,lru,private
0x0000000800000040 8124 31 ______A_________________P________ active,private
0x0000000000000040 219 0 ______A__________________________ active
0x0000000800000060 1 0 _____lA_________________P________ lru,active,private
0x0000000000000068 322 1 ___U_lA__________________________ uptodate,lru,active
0x0001000000000068 12 0 ___U_lA______________________I___ uptodate,lru,active,readahead
0x0000000400000068 13 0 ___U_lA________________d_________ uptodate,lru,active,mappedtodisk
0x0000000800000068 12 0 ___U_lA_________________P________ uptodate,lru,active,private
0x000000000000006c 977 3 __RU_lA__________________________ referenced,uptodate,lru,active
0x000100000000006c 48 0 __RU_lA______________________I___ referenced,uptodate,lru,active,readahead
0x000000040000006c 5 0 __RU_lA________________d_________ referenced,uptodate,lru,active,mappedtodisk
0x000000080000006c 3 0 __RU_lA_________________P________ referenced,uptodate,lru,active,private
0x0000000c0000006c 3 0 __RU_lA________________dP________ referenced,uptodate,lru,active,mappedtodisk,private
0x0000000c00000068 1 0 ___U_lA________________dP________ uptodate,lru,active,mappedtodisk,private
0x0000000000004078 1 0 ___UDlA_______b__________________ uptodate,dirty,lru,active,swapbacked
0x000000000000407c 34 0 __RUDlA_______b__________________ referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400 538 2 __________B______________________ buddy
0x0000000000000804 1 0 __R________M_____________________ referenced,mmap
0x0000000000000828 1029 4 ___U_l_____M_____________________ uptodate,lru,mmap
0x0001000000000828 43 0 ___U_l_____M_________________I___ uptodate,lru,mmap,readahead
0x000000000000082c 382 1 __RU_l_____M_____________________ referenced,uptodate,lru,mmap
0x000100000000082c 12 0 __RU_l_____M_________________I___ referenced,uptodate,lru,mmap,readahead
0x0000000000000868 192 0 ___U_lA____M_____________________ uptodate,lru,active,mmap
0x0001000000000868 12 0 ___U_lA____M_________________I___ uptodate,lru,active,mmap,readahead
0x000000000000086c 800 3 __RU_lA____M_____________________ referenced,uptodate,lru,active,mmap
0x000100000000086c 31 0 __RU_lA____M_________________I___ referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878 2 0 ___UDlA____M__b__________________ uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000 492 1 ____________a____________________ anonymous
0x0000000000005008 2 0 ___U________a_b__________________ uptodate,anonymous,swapbacked
0x0000000000005808 4 0 ___U_______Ma_b__________________ uptodate,mmap,anonymous,swapbacked
0x000000000000580c 1 0 __RU_______Ma_b__________________ referenced,uptodate,mmap,anonymous,swapbacked
0x0000000000005868 2839 11 ___U_lA____Ma_b__________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 29 0 __RU_lA____Ma_b__________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 513968 2007
# ./page-types --raw --list --no-summary --bits reserved
offset count flags
0 15 _____________________r___________
31 4 _____________________r___________
159 97 _____________________r___________
4096 2067 _____________________r___________
6752 2390 _____________________r___________
9355 3 _____________________r___________
9728 14526 _____________________r___________
This patch:
Introduce PageHuge(), which identifies huge/gigantic pages by their
dedicated compound destructor functions.
Also move prep_compound_gigantic_page() to hugetlb.c and make
__free_pages_ok() non-static.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-17 06:32:22 +08:00
|
|
|
static inline int PageHuge(struct page *page)
|
|
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2008-07-24 12:27:23 +08:00
|
|
|
static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
|
|
|
|
|
{
|
|
|
|
|
}
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
static inline unsigned long hugetlb_total_pages(void)
|
|
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2007-11-15 08:59:33 +08:00
|
|
|
#define follow_hugetlb_page(m,v,p,vs,a,b,i,w) ({ BUG(); 0; })
|
2005-04-17 06:20:36 +08:00
|
|
|
#define follow_huge_addr(mm, addr, write) ERR_PTR(-EINVAL)
|
|
|
|
|
#define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; })
|
2008-10-16 03:50:22 +08:00
|
|
|
static inline void hugetlb_report_meminfo(struct seq_file *m)
|
|
|
|
|
{
|
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
#define hugetlb_report_node_meminfo(n, buf) 0
|
2013-04-30 06:07:48 +08:00
|
|
|
static inline void hugetlb_show_meminfo(void)
|
|
|
|
|
{
|
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
#define follow_huge_pmd(mm, addr, pmd, write) NULL
|
2008-07-24 12:27:50 +08:00
|
|
|
#define follow_huge_pud(mm, addr, pud, write) NULL
|
2008-07-24 12:27:41 +08:00
|
|
|
#define prepare_hugepage_range(file, addr, len) (-EINVAL)
|
2005-04-17 06:20:36 +08:00
|
|
|
#define pmd_huge(x) 0
|
2008-07-24 12:27:50 +08:00
|
|
|
#define pud_huge(x) 0
|
2005-04-17 06:20:36 +08:00
|
|
|
#define is_hugepage_only_range(mm, addr, len) 0
|
[PATCH] hugepage: Fix hugepage logic in free_pgtables()
free_pgtables() has special logic to call hugetlb_free_pgd_range() instead
of the normal free_pgd_range() on hugepage VMAs. However, the test it uses
to do so is incorrect: it calls is_hugepage_only_range on a hugepage sized
range at the start of the vma. is_hugepage_only_range() will return true
if the given range has any intersection with a hugepage address region, and
in this case the given region need not be hugepage aligned. So, for
example, this test can return true if called on, say, a 4k VMA immediately
preceding a (nicely aligned) hugepage VMA.
At present we get away with this because the powerpc version of
hugetlb_free_pgd_range() is just a call to free_pgd_range(). On ia64 (the
only other arch with a non-trivial is_hugepage_only_range()) we get away
with it for a different reason; the hugepage area is not contiguous with
the rest of the user address space, and VMAs are not permitted in between,
so the test can't return a false positive there.
Nonetheless this should be fixed. We do that in the patch below by
replacing the is_hugepage_only_range() test with an explicit test of the
VMA using is_vm_hugetlb_page().
This in turn changes behaviour for platforms where is_hugepage_only_range()
returns false always (everything except powerpc and ia64). We address this
by ensuring that hugetlb_free_pgd_range() is defined to be identical to
free_pgd_range() (instead of a no-op) on everything except ia64. Even so,
it will prevent some otherwise possible coalescing of calls down to
free_pgd_range(). Since this only happens for hugepage VMAs, removing this
small optimization seems unlikely to cause any trouble.
This patch causes no regressions on the libhugetlbfs testsuite - ppc64
POWER5 (8-way), ppc64 G5 (2-way) and i386 Pentium M (UP).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 16:08:57 +08:00
|
|
|
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
|
2009-06-23 20:49:05 +08:00
|
|
|
#define hugetlb_fault(mm, vma, addr, flags) ({ BUG(); 0; })
|
2010-05-28 08:29:16 +08:00
|
|
|
#define huge_pte_offset(mm, address) 0
|
2012-08-01 07:42:03 +08:00
|
|
|
static inline int dequeue_hwpoisoned_huge_page(struct page *page)
|
|
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
mm: migrate: make core migration code aware of hugepage
Currently hugepage migration is available only for soft offlining, but
it's also useful for some other users of page migration (clearly because
users of hugepage can enjoy the benefit of mempolicy and memory hotplug.)
So this patchset tries to extend such users to support hugepage migration.
The target of this patchset is to enable hugepage migration for NUMA
related system calls (migrate_pages(2), move_pages(2), and mbind(2)), and
memory hotplug.
This patchset does not add hugepage migration for memory compaction,
because users of memory compaction mainly expect to construct thp by
arranging raw pages, and there's little or no need to compact hugepages.
CMA, another user of page migration, can have benefit from hugepage
migration, but is not enabled to support it for now (just because of lack
of testing and expertise in CMA.)
Hugepage migration of non pmd-based hugepage (for example 1GB hugepage in
x86_64, or hugepages in architectures like ia64) is not enabled for now
(again, because of lack of testing.)
As for how these are achived, I extended the API (migrate_pages()) to
handle hugepage (with patch 1 and 2) and adjusted code of each caller to
check and collect movable hugepages (with patch 3-7). Remaining 2 patches
are kind of miscellaneous ones to avoid unexpected behavior. Patch 8 is
about making sure that we only migrate pmd-based hugepages. And patch 9
is about choosing appropriate zone for hugepage allocation.
My test is mainly functional one, simply kicking hugepage migration via
each entry point and confirm that migration is done correctly. Test code
is available here:
git://github.com/Naoya-Horiguchi/test_hugepage_migration_extension.git
And I always run libhugetlbfs test when changing hugetlbfs's code. With
this patchset, no regression was found in the test.
This patch (of 9):
Before enabling each user of page migration to support hugepage,
this patch enables the list of pages for migration to link not only
LRU pages, but also hugepages. As a result, putback_movable_pages()
and migrate_pages() can handle both of LRU pages and hugepages.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 05:21:59 +08:00
|
|
|
#define isolate_huge_page(p, l) false
|
|
|
|
|
#define putback_active_hugepage(p) do {} while (0)
|
2010-09-08 09:19:34 +08:00
|
|
|
static inline void copy_huge_page(struct page *dst, struct page *src)
|
|
|
|
|
{
|
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2012-11-19 10:14:23 +08:00
|
|
|
static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
|
|
|
|
|
unsigned long address, unsigned long end, pgprot_t newprot)
|
|
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
2006-03-22 16:08:50 +08:00
|
|
|
|
mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
If a process creates a large hugetlbfs mapping that is eligible for page
table sharing and forks heavily with children some of whom fault and
others which destroy the mapping then it is possible for page tables to
get corrupted. Some teardowns of the mapping encounter a "bad pmd" and
output a message to the kernel log. The final teardown will trigger a
BUG_ON in mm/filemap.c.
This was reproduced in 3.4 but is known to have existed for a long time
and goes back at least as far as 2.6.37. It was probably was introduced
in 2.6.20 by [39dde65c: shared page table for hugetlb page]. The messages
look like this;
[ ..........] Lots of bad pmd messages followed by this
[ 127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7).
[ 127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7).
[ 127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7).
[ 127.186778] ------------[ cut here ]------------
[ 127.186781] kernel BUG at mm/filemap.c:134!
[ 127.186782] invalid opcode: 0000 [#1] SMP
[ 127.186783] CPU 7
[ 127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod
[ 127.186801]
[ 127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR
[ 127.186804] RIP: 0010:[<ffffffff810ed6ce>] [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[ 127.186809] RSP: 0000:ffff8804144b5c08 EFLAGS: 00010002
[ 127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0
[ 127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00
[ 127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003
[ 127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8
[ 127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8
[ 127.186815] FS: 00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
[ 127.186816] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0
[ 127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0)
[ 127.186821] Stack:
[ 127.186822] ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b
[ 127.186824] ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98
[ 127.186825] ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000
[ 127.186827] Call Trace:
[ 127.186829] [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80
[ 127.186832] [<ffffffff811bc925>] truncate_hugepages+0x115/0x220
[ 127.186834] [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30
[ 127.186837] [<ffffffff811655c7>] evict+0xa7/0x1b0
[ 127.186839] [<ffffffff811657a3>] iput_final+0xd3/0x1f0
[ 127.186840] [<ffffffff811658f9>] iput+0x39/0x50
[ 127.186842] [<ffffffff81162708>] d_kill+0xf8/0x130
[ 127.186843] [<ffffffff81162812>] dput+0xd2/0x1a0
[ 127.186845] [<ffffffff8114e2d0>] __fput+0x170/0x230
[ 127.186848] [<ffffffff81236e0e>] ? rb_erase+0xce/0x150
[ 127.186849] [<ffffffff8114e3ad>] fput+0x1d/0x30
[ 127.186851] [<ffffffff81117db7>] remove_vma+0x37/0x80
[ 127.186853] [<ffffffff81119182>] do_munmap+0x2d2/0x360
[ 127.186855] [<ffffffff811cc639>] sys_shmdt+0xc9/0x170
[ 127.186857] [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b
[ 127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0
[ 127.186868] RIP [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[ 127.186870] RSP <ffff8804144b5c08>
[ 127.186871] ---[ end trace 7cbac5d1db69f426 ]---
The bug is a race and not always easy to reproduce. To reproduce it I was
doing the following on a single socket I7-based machine with 16G of RAM.
$ hugeadm --pool-pages-max DEFAULT:13G
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall
$ for i in `seq 1 9000`; do ./hugetlbfs-test; done
On my particular machine, it usually triggers within 10 minutes but
enabling debug options can change the timing such that it never hits.
Once the bug is triggered, the machine is in trouble and needs to be
rebooted. The machine will respond but processes accessing proc like "ps
aux" will hang due to the BUG_ON. shutdown will also hang and needs a
hard reset or a sysrq-b.
The basic problem is a race between page table sharing and teardown. For
the most part page table sharing depends on i_mmap_mutex. In some cases,
it is also taking the mm->page_table_lock for the PTE updates but with
shared page tables, it is the i_mmap_mutex that is more important.
Unfortunately it appears to be also insufficient. Consider the following
situation
Process A Process B
--------- ---------
hugetlb_fault shmdt
LockWrite(mmap_sem)
do_munmap
unmap_region
unmap_vmas
unmap_single_vma
unmap_hugepage_range
Lock(i_mmap_mutex)
Lock(mm->page_table_lock)
huge_pmd_unshare/unmap tables <--- (1)
Unlock(mm->page_table_lock)
Unlock(i_mmap_mutex)
huge_pte_alloc ...
Lock(i_mmap_mutex) ...
vma_prio_walk, find svma, spte ...
Lock(mm->page_table_lock) ...
share spte ...
Unlock(mm->page_table_lock) ...
Unlock(i_mmap_mutex) ...
hugetlb_no_page <--- (2)
free_pgtables
unlink_file_vma
hugetlb_free_pgd_range
remove_vma_list
In this scenario, it is possible for Process A to share page tables with
Process B that is trying to tear them down. The i_mmap_mutex on its own
does not prevent Process A walking Process B's page tables. At (1) above,
the page tables are not shared yet so it unmaps the PMDs. Process A sets
up page table sharing and at (2) faults a new entry. Process B then trips
up on it in free_pgtables.
This patch fixes the problem by adding a new function
__unmap_hugepage_range_final that is only called when the VMA is about to
be destroyed. This function clears VM_MAYSHARE during
unmap_hugepage_range() under the i_mmap_mutex. This makes the VMA
ineligible for sharing and avoids the race. Superficially this looks like
it would then be vunerable to truncate and madvise issues but hugetlbfs
has its own truncate handlers so does not use unmap_mapping_range() and
does not support madvise(DONTNEED).
This should be treated as a -stable candidate if it is merged.
Test program is as follows. The test case was mostly written by Michal
Hocko with a few minor changes to reproduce this bug.
==== CUT HERE ====
static size_t huge_page_size = (2UL << 20);
static size_t nr_huge_page_A = 512;
static size_t nr_huge_page_B = 5632;
unsigned int get_random(unsigned int max)
{
struct timeval tv;
gettimeofday(&tv, NULL);
srandom(tv.tv_usec);
return random() % max;
}
static void play(void *addr, size_t size)
{
unsigned char *start = addr,
*end = start + size,
*a;
start += get_random(size/2);
/* we could itterate on huge pages but let's give it more time. */
for (a = start; a < end; a += 4096)
*a = 0;
}
int main(int argc, char **argv)
{
key_t key = IPC_PRIVATE;
size_t sizeA = nr_huge_page_A * huge_page_size;
size_t sizeB = nr_huge_page_B * huge_page_size;
int shmidA, shmidB;
void *addrA = NULL, *addrB = NULL;
int nr_children = 300, n = 0;
if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
perror("shmget:");
return 1;
}
if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) {
perror("shmat");
return 1;
}
if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
perror("shmget:");
return 1;
}
if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) {
perror("shmat");
return 1;
}
fork_child:
switch(fork()) {
case 0:
switch (n%3) {
case 0:
play(addrA, sizeA);
break;
case 1:
play(addrB, sizeB);
break;
case 2:
break;
}
break;
case -1:
perror("fork:");
break;
default:
if (++n < nr_children)
goto fork_child;
play(addrA, sizeA);
break;
}
shmdt(addrA);
shmdt(addrB);
do {
wait(NULL);
} while (--n > 0);
shmctl(shmidA, IPC_RMID, NULL);
shmctl(shmidB, IPC_RMID, NULL);
return 0;
}
[akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:46:20 +08:00
|
|
|
static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb,
|
|
|
|
|
struct vm_area_struct *vma, unsigned long start,
|
|
|
|
|
unsigned long end, struct page *ref_page)
|
|
|
|
|
{
|
|
|
|
|
BUG();
|
|
|
|
|
}
|
|
|
|
|
|
2012-08-01 07:42:03 +08:00
|
|
|
static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
|
|
|
|
|
struct vm_area_struct *vma, unsigned long start,
|
|
|
|
|
unsigned long end, struct page *ref_page)
|
|
|
|
|
{
|
|
|
|
|
BUG();
|
|
|
|
|
}
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#endif /* !CONFIG_HUGETLB_PAGE */
|
|
|
|
|
|
2009-09-22 08:03:47 +08:00
|
|
|
#define HUGETLB_ANON_FILE "anon_hugepage"
|
|
|
|
|
|
2009-09-22 08:03:43 +08:00
|
|
|
enum {
|
|
|
|
|
/*
|
|
|
|
|
* The file will be used as an shm file so shmfs accounting rules
|
|
|
|
|
* apply
|
|
|
|
|
*/
|
|
|
|
|
HUGETLB_SHMFS_INODE = 1,
|
2009-09-22 08:03:47 +08:00
|
|
|
/*
|
|
|
|
|
* The file is being created on the internal vfs mount and shmfs
|
|
|
|
|
* accounting rules do not apply
|
|
|
|
|
*/
|
|
|
|
|
HUGETLB_ANONHUGE_INODE = 2,
|
2009-09-22 08:03:43 +08:00
|
|
|
};
|
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#ifdef CONFIG_HUGETLBFS
|
|
|
|
|
struct hugetlbfs_sb_info {
|
|
|
|
|
long max_inodes; /* inodes allowed */
|
|
|
|
|
long free_inodes; /* inodes free */
|
|
|
|
|
spinlock_t stat_lock;
|
2008-07-24 12:27:43 +08:00
|
|
|
struct hstate *hstate;
|
hugepages: fix use after free bug in "quota" handling
hugetlbfs_{get,put}_quota() are badly named. They don't interact with the
general quota handling code, and they don't much resemble its behaviour.
Rather than being about maintaining limits on on-disk block usage by
particular users, they are instead about maintaining limits on in-memory
page usage (including anonymous MAP_PRIVATE copied-on-write pages)
associated with a particular hugetlbfs filesystem instance.
Worse, they work by having callbacks to the hugetlbfs filesystem code from
the low-level page handling code, in particular from free_huge_page().
This is a layering violation of itself, but more importantly, if the
kernel does a get_user_pages() on hugepages (which can happen from KVM
amongst others), then the free_huge_page() can be delayed until after the
associated inode has already been freed. If an unmount occurs at the
wrong time, even the hugetlbfs superblock where the "quota" limits are
stored may have been freed.
Andrew Barry proposed a patch to fix this by having hugepages, instead of
storing a pointer to their address_space and reaching the superblock from
there, had the hugepages store pointers directly to the superblock,
bumping the reference count as appropriate to avoid it being freed.
Andrew Morton rejected that version, however, on the grounds that it made
the existing layering violation worse.
This is a reworked version of Andrew's patch, which removes the extra, and
some of the existing, layering violation. It works by introducing the
concept of a hugepage "subpool" at the lower hugepage mm layer - that is a
finite logical pool of hugepages to allocate from. hugetlbfs now creates
a subpool for each filesystem instance with a page limit set, and a
pointer to the subpool gets added to each allocated hugepage, instead of
the address_space pointer used now. The subpool has its own lifetime and
is only freed once all pages in it _and_ all other references to it (i.e.
superblocks) are gone.
subpools are optional - a NULL subpool pointer is taken by the code to
mean that no subpool limits are in effect.
Previous discussion of this bug found in: "Fix refcounting in hugetlbfs
quota handling.". See: https://lkml.org/lkml/2011/8/11/28 or
http://marc.info/?l=linux-mm&m=126928970510627&w=1
v2: Fixed a bug spotted by Hillf Danton, and removed the extra parameter to
alloc_huge_page() - since it already takes the vma, it is not necessary.
Signed-off-by: Andrew Barry <abarry@cray.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-22 07:34:12 +08:00
|
|
|
struct hugepage_subpool *spool;
|
2005-04-17 06:20:36 +08:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
|
|
|
|
|
{
|
|
|
|
|
return sb->s_fs_info;
|
|
|
|
|
}
|
|
|
|
|
|
2006-03-28 17:56:42 +08:00
|
|
|
extern const struct file_operations hugetlbfs_file_operations;
|
2009-09-28 02:29:37 +08:00
|
|
|
extern const struct vm_operations_struct hugetlb_vm_ops;
|
2013-05-08 07:18:13 +08:00
|
|
|
struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
|
2012-12-12 08:01:34 +08:00
|
|
|
struct user_struct **user, int creat_flags,
|
|
|
|
|
int page_size_log);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
static inline int is_file_hugepages(struct file *file)
|
|
|
|
|
{
|
2007-03-02 07:46:08 +08:00
|
|
|
if (file->f_op == &hugetlbfs_file_operations)
|
|
|
|
|
return 1;
|
|
|
|
|
if (is_file_shm_hugepages(file))
|
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
|
|
return 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
2012-12-12 08:01:34 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#else /* !CONFIG_HUGETLBFS */
|
|
|
|
|
|
2009-02-11 06:27:32 +08:00
|
|
|
#define is_file_hugepages(file) 0
|
2012-03-22 07:34:14 +08:00
|
|
|
static inline struct file *
|
2013-05-08 07:18:13 +08:00
|
|
|
hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
|
|
|
|
|
struct user_struct **user, int creat_flags,
|
2012-12-12 08:01:34 +08:00
|
|
|
int page_size_log)
|
2009-09-25 05:47:45 +08:00
|
|
|
{
|
|
|
|
|
return ERR_PTR(-ENOSYS);
|
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
|
#endif /* !CONFIG_HUGETLBFS */
|
|
|
|
|
|
2007-05-07 05:49:00 +08:00
|
|
|
#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
|
|
|
|
|
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
|
|
|
|
unsigned long len, unsigned long pgoff,
|
|
|
|
|
unsigned long flags);
|
|
|
|
|
#endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
|
|
|
|
|
|
2008-07-24 12:27:41 +08:00
|
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
|
|
|
|
2008-07-24 12:27:44 +08:00
|
|
|
#define HSTATE_NAME_LEN 32
|
2008-07-24 12:27:41 +08:00
|
|
|
/* Defines one hugetlb page size */
|
|
|
|
|
struct hstate {
|
2009-09-22 08:01:22 +08:00
|
|
|
int next_nid_to_alloc;
|
|
|
|
|
int next_nid_to_free;
|
2008-07-24 12:27:41 +08:00
|
|
|
unsigned int order;
|
|
|
|
|
unsigned long mask;
|
|
|
|
|
unsigned long max_huge_pages;
|
|
|
|
|
unsigned long nr_huge_pages;
|
|
|
|
|
unsigned long free_huge_pages;
|
|
|
|
|
unsigned long resv_huge_pages;
|
|
|
|
|
unsigned long surplus_huge_pages;
|
|
|
|
|
unsigned long nr_overcommit_huge_pages;
|
2012-08-01 07:42:07 +08:00
|
|
|
struct list_head hugepage_activelist;
|
2008-07-24 12:27:41 +08:00
|
|
|
struct list_head hugepage_freelists[MAX_NUMNODES];
|
|
|
|
|
unsigned int nr_huge_pages_node[MAX_NUMNODES];
|
|
|
|
|
unsigned int free_huge_pages_node[MAX_NUMNODES];
|
|
|
|
|
unsigned int surplus_huge_pages_node[MAX_NUMNODES];
|
2012-08-01 07:42:24 +08:00
|
|
|
#ifdef CONFIG_CGROUP_HUGETLB
|
|
|
|
|
/* cgroup control files */
|
|
|
|
|
struct cftype cgroup_files[5];
|
|
|
|
|
#endif
|
2008-07-24 12:27:44 +08:00
|
|
|
char name[HSTATE_NAME_LEN];
|
2008-07-24 12:27:41 +08:00
|
|
|
};
|
|
|
|
|
|
2008-07-24 12:27:52 +08:00
|
|
|
struct huge_bootmem_page {
|
|
|
|
|
struct list_head list;
|
|
|
|
|
struct hstate *hstate;
|
2011-07-26 08:11:50 +08:00
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
|
|
|
phys_addr_t phys;
|
|
|
|
|
#endif
|
2008-07-24 12:27:52 +08:00
|
|
|
};
|
|
|
|
|
|
2010-09-08 09:19:33 +08:00
|
|
|
struct page *alloc_huge_page_node(struct hstate *h, int nid);
|
2013-09-12 05:22:06 +08:00
|
|
|
struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
|
|
|
|
|
unsigned long addr, int avoid_reserve);
|
2010-09-08 09:19:33 +08:00
|
|
|
|
2008-07-24 12:27:52 +08:00
|
|
|
/* arch callback */
|
|
|
|
|
int __init alloc_bootmem_huge_page(struct hstate *h);
|
|
|
|
|
|
2008-07-24 12:27:42 +08:00
|
|
|
void __init hugetlb_add_hstate(unsigned order);
|
|
|
|
|
struct hstate *size_to_hstate(unsigned long size);
|
|
|
|
|
|
|
|
|
|
#ifndef HUGE_MAX_HSTATE
|
|
|
|
|
#define HUGE_MAX_HSTATE 1
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
extern struct hstate hstates[HUGE_MAX_HSTATE];
|
|
|
|
|
extern unsigned int default_hstate_idx;
|
|
|
|
|
|
|
|
|
|
#define default_hstate (hstates[default_hstate_idx])
|
2008-07-24 12:27:41 +08:00
|
|
|
|
2008-07-24 12:27:43 +08:00
|
|
|
static inline struct hstate *hstate_inode(struct inode *i)
|
2008-07-24 12:27:41 +08:00
|
|
|
{
|
2008-07-24 12:27:43 +08:00
|
|
|
struct hugetlbfs_sb_info *hsb;
|
|
|
|
|
hsb = HUGETLBFS_SB(i->i_sb);
|
|
|
|
|
return hsb->hstate;
|
2008-07-24 12:27:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline struct hstate *hstate_file(struct file *f)
|
|
|
|
|
{
|
2013-01-24 06:07:38 +08:00
|
|
|
return hstate_inode(file_inode(f));
|
2008-07-24 12:27:41 +08:00
|
|
|
}
|
|
|
|
|
|
2013-05-08 07:18:13 +08:00
|
|
|
static inline struct hstate *hstate_sizelog(int page_size_log)
|
|
|
|
|
{
|
|
|
|
|
if (!page_size_log)
|
|
|
|
|
return &default_hstate;
|
|
|
|
|
return size_to_hstate(1 << page_size_log);
|
|
|
|
|
}
|
|
|
|
|
|
2008-07-24 12:27:43 +08:00
|
|
|
static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
|
2008-07-24 12:27:41 +08:00
|
|
|
{
|
2008-07-24 12:27:43 +08:00
|
|
|
return hstate_file(vma->vm_file);
|
2008-07-24 12:27:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned long huge_page_size(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return (unsigned long)PAGE_SIZE << h->order;
|
|
|
|
|
}
|
|
|
|
|
|
2009-01-07 06:38:53 +08:00
|
|
|
extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma);
|
|
|
|
|
|
2009-01-07 06:38:54 +08:00
|
|
|
extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
|
|
|
|
|
|
2008-07-24 12:27:41 +08:00
|
|
|
static inline unsigned long huge_page_mask(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return h->mask;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned int huge_page_order(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return h->order;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned huge_page_shift(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return h->order + PAGE_SHIFT;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned int pages_per_huge_page(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return 1 << h->order;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned int blocks_per_huge_page(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return huge_page_size(h) / 512;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#include <asm/hugetlb.h>
|
|
|
|
|
|
2012-04-02 02:01:34 +08:00
|
|
|
#ifndef arch_make_huge_pte
|
|
|
|
|
static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
|
|
|
|
|
struct page *page, int writable)
|
|
|
|
|
{
|
|
|
|
|
return entry;
|
|
|
|
|
}
|
|
|
|
|
#endif
|
|
|
|
|
|
2008-07-24 12:27:42 +08:00
|
|
|
static inline struct hstate *page_hstate(struct page *page)
|
|
|
|
|
{
|
|
|
|
|
return size_to_hstate(PAGE_SIZE << compound_order(page));
|
|
|
|
|
}
|
|
|
|
|
|
2010-10-07 03:45:00 +08:00
|
|
|
static inline unsigned hstate_index_to_shift(unsigned index)
|
|
|
|
|
{
|
|
|
|
|
return hstates[index].order + PAGE_SHIFT;
|
|
|
|
|
}
|
|
|
|
|
|
2012-08-01 07:42:00 +08:00
|
|
|
static inline int hstate_index(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return h - hstates;
|
|
|
|
|
}
|
|
|
|
|
|
2013-06-25 21:19:31 +08:00
|
|
|
pgoff_t __basepage_index(struct page *page);
|
|
|
|
|
|
|
|
|
|
/* Return page->index in PAGE_SIZE units */
|
|
|
|
|
static inline pgoff_t basepage_index(struct page *page)
|
|
|
|
|
{
|
|
|
|
|
if (!PageCompound(page))
|
|
|
|
|
return page->index;
|
|
|
|
|
|
|
|
|
|
return __basepage_index(page);
|
|
|
|
|
}
|
|
|
|
|
|
2013-05-08 07:18:13 +08:00
|
|
|
#else /* CONFIG_HUGETLB_PAGE */
|
2008-07-24 12:27:41 +08:00
|
|
|
struct hstate {};
|
2010-09-08 09:19:33 +08:00
|
|
|
#define alloc_huge_page_node(h, nid) NULL
|
2013-09-12 05:22:06 +08:00
|
|
|
#define alloc_huge_page_noerr(v, a, r) NULL
|
2008-07-24 12:27:52 +08:00
|
|
|
#define alloc_bootmem_huge_page(h) NULL
|
2008-07-24 12:27:41 +08:00
|
|
|
#define hstate_file(f) NULL
|
2013-05-08 07:18:13 +08:00
|
|
|
#define hstate_sizelog(s) NULL
|
2008-07-24 12:27:41 +08:00
|
|
|
#define hstate_vma(v) NULL
|
|
|
|
|
#define hstate_inode(i) NULL
|
|
|
|
|
#define huge_page_size(h) PAGE_SIZE
|
|
|
|
|
#define huge_page_mask(h) PAGE_MASK
|
2009-01-07 06:38:53 +08:00
|
|
|
#define vma_kernel_pagesize(v) PAGE_SIZE
|
2009-01-07 06:38:54 +08:00
|
|
|
#define vma_mmu_pagesize(v) PAGE_SIZE
|
2008-07-24 12:27:41 +08:00
|
|
|
#define huge_page_order(h) 0
|
|
|
|
|
#define huge_page_shift(h) PAGE_SHIFT
|
2008-07-27 06:22:27 +08:00
|
|
|
static inline unsigned int pages_per_huge_page(struct hstate *h)
|
|
|
|
|
{
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
2010-10-07 03:45:00 +08:00
|
|
|
#define hstate_index_to_shift(index) 0
|
2012-08-01 07:42:00 +08:00
|
|
|
#define hstate_index(h) 0
|
2013-06-25 21:19:31 +08:00
|
|
|
|
|
|
|
|
static inline pgoff_t basepage_index(struct page *page)
|
|
|
|
|
{
|
|
|
|
|
return page->index;
|
|
|
|
|
}
|
2013-05-08 07:18:13 +08:00
|
|
|
#endif /* CONFIG_HUGETLB_PAGE */
|
2008-07-24 12:27:41 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
#endif /* _LINUX_HUGETLB_H */
|
