linux-stable.git/include/linux/hugetlb.h, branch v5.4.71

mm/hugetlb: fix build failure with HUGETLB_PAGE but not HUGEBTLBFS

2020-04-23T08:36:36+00:00

[ Upstream commit bb297bb2de517e41199185021f043bbc5d75b377 ]

When CONFIG_HUGETLB_PAGE is set but not CONFIG_HUGETLBFS, the following
build failure is encoutered:

  In file included from arch/powerpc/mm/fault.c:33:0:
  include/linux/hugetlb.h: In function 'hstate_inode':
  include/linux/hugetlb.h:477:9: error: implicit declaration of function 'HUGETLBFS_SB' [-Werror=implicit-function-declaration]
    return HUGETLBFS_SB(i->i_sb)->hstate;
           ^
  include/linux/hugetlb.h:477:30: error: invalid type argument of '->' (have 'int')
    return HUGETLBFS_SB(i->i_sb)->hstate;
                                ^

Gate hstate_inode() with CONFIG_HUGETLBFS instead of CONFIG_HUGETLB_PAGE.

Fixes: a137e1cc6d6e ("hugetlbfs: per mount huge page sizes")
Reported-by: kbuild test robot 
Signed-off-by: Christophe Leroy 
Signed-off-by: Andrew Morton 
Reviewed-by: Mike Kravetz 
Cc: Baoquan He 
Cc: Nishanth Aravamudan 
Cc: Nick Piggin 
Cc: Adam Litke 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr
Link: https://patchwork.ozlabs.org/patch/1255548/#2386036
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

mm: introduce page_size()

2019-09-24T22:54:08+00:00

Patch series "Make working with compound pages easier", v2.

These three patches add three helpers and convert the appropriate
places to use them.

This patch (of 3):

It's unnecessarily hard to find out the size of a potentially huge page.
Replace 'PAGE_SIZE << compound_order(page)' with page_size(page).

Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: Michal Hocko 
Reviewed-by: Andrew Morton 
Reviewed-by: Ira Weiny 
Acked-by: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move the powerpc hugepd code to mm/gup.c

2019-07-12T18:05:45+00:00

While only powerpc supports the hugepd case, the code is pretty generic
and I'd like to keep all GUP internals in one place.

Link: http://lkml.kernel.org/r/20190625143715.1689-15-hch@lst.de
Signed-off-by: Christoph Hellwig 
Cc: Andrey Konovalov 
Cc: Benjamin Herrenschmidt 
Cc: David Miller 
Cc: James Hogan 
Cc: Jason Gunthorpe 
Cc: Khalid Aziz 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Paul Burton 
Cc: Paul Mackerras 
Cc: Ralf Baechle 
Cc: Rich Felker 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make !CONFIG_HUGE_PAGE wrappers into static inlines

2019-07-12T18:05:42+00:00

Instead of using defines, which loses type safety and provokes unused
variable warnings from gcc, put the constants into static inlines.

Link: http://lkml.kernel.org/r/20190522235102.GA15370@mellanox.com
Signed-off-by: Jason Gunthorpe 
Suggested-by: Andrew Morton 
Reviewed-by: Mike Kravetz 
Cc: Jerome Glisse 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: use same fault hash key for shared and private mappings

2019-05-14T16:47:48+00:00

hugetlb uses a fault mutex hash table to prevent page faults of the
same pages concurrently.  The key for shared and private mappings is
different.  Shared keys off address_space and file index.  Private keys
off mm and virtual address.  Consider a private mappings of a populated
hugetlbfs file.  A fault will map the page from the file and if needed
do a COW to map a writable page.

Hugetlbfs hole punch uses the fault mutex to prevent mappings of file
pages.  It uses the address_space file index key.  However, private
mappings will use a different key and could race with this code to map
the file page.  This causes problems (BUG) for the page cache remove
code as it expects the page to be unmapped.  A sample stack is:

page dumped because: VM_BUG_ON_PAGE(page_mapped(page))
kernel BUG at mm/filemap.c:169!
...
RIP: 0010:unaccount_page_cache_page+0x1b8/0x200
...
Call Trace:
__delete_from_page_cache+0x39/0x220
delete_from_page_cache+0x45/0x70
remove_inode_hugepages+0x13c/0x380
? __add_to_page_cache_locked+0x162/0x380
hugetlbfs_fallocate+0x403/0x540
? _cond_resched+0x15/0x30
? __inode_security_revalidate+0x5d/0x70
? selinux_file_permission+0x100/0x130
vfs_fallocate+0x13f/0x270
ksys_fallocate+0x3c/0x80
__x64_sys_fallocate+0x1a/0x20
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9

There seems to be another potential COW issue/race with this approach
of different private and shared keys as noted in commit 8382d914ebf7
("mm, hugetlb: improve page-fault scalability").

Since every hugetlb mapping (even anon and private) is actually a file
mapping, just use the address_space index key for all mappings.  This
results in potentially more hash collisions.  However, this should not
be the common case.

Link: http://lkml.kernel.org/r/20190328234704.27083-3-mike.kravetz@oracle.com
Link: http://lkml.kernel.org/r/20190412165235.t4sscoujczfhuiyt@linux-r8p5
Fixes: b5cec28d36f5 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Mike Kravetz 
Reviewed-by: Naoya Horiguchi 
Reviewed-by: Davidlohr Bueso 
Cc: Joonsoo Kim 
Cc: "Kirill A . Shutemov" 
Cc: Michal Hocko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

include/linux/hugetlb.h: convert to use vm_fault_t

2019-03-29T17:01:37+00:00

kbuild produces the below warning:

  tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
  head:   5453a3df2a5eb49bc24615d4cf0d66b2aae05e5f
  commit 3d3539018d2c ("mm: create the new vm_fault_t type")
  reproduce:
        # apt-get install sparse
        git checkout 3d3539018d2cbd12e5af4a132636ee7fd8d43ef0
        make ARCH=x86_64 allmodconfig
        make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

  >> mm/memory.c:3968:21: sparse: incorrect type in assignment (different
  >> base types) @@    expected restricted vm_fault_t [usertype] ret @@
  >> got e] ret @@
     mm/memory.c:3968:21:    expected restricted vm_fault_t [usertype] ret
     mm/memory.c:3968:21:    got int

This patch converts to return vm_fault_t type for hugetlb_fault() when
CONFIG_HUGETLB_PAGE=n.

Regarding the sparse warning, Luc said:

: This is the expected behaviour.  The constant 0 is magic regarding bitwise
: types but ({ ...; 0; }) is not, it is just an ordinary expression of type
: 'int'.
:
: So, IMHO, Souptick's patch is the right thing to do.

Link: http://lkml.kernel.org/r/20190318162604.GA31553@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder 
Reviewed-by: Mike Kravetz 
Cc: Matthew Wilcox 
Cc: Luc Van Oostenryck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: update get_user_pages_longterm to migrate pages allocated from CMA region

2019-03-06T05:07:19+00:00

This patch updates get_user_pages_longterm to migrate pages allocated
out of CMA region.  This makes sure that we don't keep non-movable pages
(due to page reference count) in the CMA area.

This will be used by ppc64 in a later patch to avoid pinning pages in
the CMA region.  ppc64 uses CMA region for allocation of the hardware
page table (hash page table) and not able to migrate pages out of CMA
region results in page table allocation failures.

One case where we hit this easy is when a guest using a VFIO passthrough
device.  VFIO locks all the guest's memory and if the guest memory is
backed by CMA region, it becomes unmovable resulting in fragmenting the
CMA and possibly preventing other guests from allocation a large enough
hash page table.

NOTE: We allocate the new page without using __GFP_THISNODE

Link: http://lkml.kernel.org/r/20190114095438.32470-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V 
Cc: Alexey Kardashevskiy 
Cc: Andrea Arcangeli 
Cc: David Gibson 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hugetlb: add prot_modify_start/commit sequence for hugetlb update

2019-03-06T05:07:18+00:00

Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte.  Follow the regular pte change protection
sequence for hugetlb too.  This allows the architectures to override the
update sequence.

Link: http://lkml.kernel.org/r/20190116085035.29729-5-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V 
Reviewed-by: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Martin Schwidefsky 
Cc: Nicholas Piggin 
Cc: Paul Mackerras 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hugetlb: enable arch specific huge page size support for migration

2019-03-06T05:07:15+00:00

Architectures like arm64 have HugeTLB page sizes which are different
than generic sizes at PMD, PUD, PGD level and implemented via contiguous
bits.  At present these special size HugeTLB pages cannot be identified
through macros like (PMD|PUD|PGDIR)_SHIFT and hence chosen not be
migrated.

Enabling migration support for these special HugeTLB page sizes along
with the generic ones (PMD|PUD|PGD) would require identifying all of
them on a given platform.  A platform specific hook can precisely
enumerate all huge page sizes supported for migration.  Instead of
comparing against standard huge page orders let
hugetlb_migration_support() function call a platform hook
arch_hugetlb_migration_support().  Default definition for the platform
hook maintains existing semantics which checks standard huge page order.
But an architecture can choose to override the default and provide
support for a comprehensive set of huge page sizes.

Link: http://lkml.kernel.org/r/1545121450-1663-4-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual 
Reviewed-by: Naoya Horiguchi 
Reviewed-by: Steve Capper 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hugetlb: enable PUD level huge page migration

2019-03-06T05:07:15+00:00

Architectures like arm64 have PUD level HugeTLB pages for certain configs
(1GB huge page is PUD based on ARM64_4K_PAGES base page size) that can
be enabled for migration.  It can be achieved through checking for
PUD_SHIFT order based HugeTLB pages during migration.

Link: http://lkml.kernel.org/r/1545121450-1663-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual 
Reviewed-by: Naoya Horiguchi 
Reviewed-by: Steve Capper 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds