linux-stable.git/include/linux/hugetlb.h, branch v5.6.2

mm: hugetlb controller for cgroups v2

2019-12-16T20:41:40+00:00

In the effort of supporting cgroups v2 into Kubernetes, I stumped on
the lack of the hugetlb controller.

When the controller is enabled, it exposes four new files for each
hugetlb size on non-root cgroups:

- hugetlb..current
- hugetlb..max
- hugetlb..events
- hugetlb..events.local

The differences with the legacy hierarchy are in the file names and
using the value "max" instead of "-1" to disable a limit.

The file .limit_in_bytes is renamed to .max.

The file .usage_in_bytes is renamed to .current.

.failcnt is not provided as a single file anymore, but its value can
be read through the new flat-keyed files .events and .events.local,
through the "max" key.

Signed-off-by: Giuseppe Scrivano 
Signed-off-by: Tejun Heo

hugetlb: remove unused hstate in hugetlb_fault_mutex_hash()

2019-12-01T20:59:08+00:00

The first parameter hstate in function hugetlb_fault_mutex_hash() is not
used anymore.

This patch removes it.

[akpm@linux-foundation.org: various build fixes]
[cai@lca.pw: fix a GCC compilation warning]
 Link: http://lkml.kernel.org/r/1570544108-32331-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/20191005003302.785-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang 
Signed-off-by: Qian Cai 
Suggested-by: Andrew Morton 
Reviewed-by: Andrew Morton 
Cc: Mike Kravetz 
Cc: Hugh Dickins 
Cc: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: convert macros to static inline, fix sparse warning

2019-12-01T20:59:08+00:00

huge_pte_offset() produced a sparse warning due to an improper return
type when the kernel was built with !CONFIG_HUGETLB_PAGE.  Fix the bad
type and also convert all the macros in this block to static inline
wrappers.  Two existing wrappers in this block had lines in excess of 80
columns so clean those up as well.

No functional change.

Link: http://lkml.kernel.org/r/20191112194558.139389-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz 
Reported-by: Ben Dooks 
Suggested-by: Jason Gunthorpe 
Cc: Michael Ellerman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: hugetlb_fault_mutex_hash() cleanup

2019-12-01T20:59:08+00:00

A new clang diagnostic (-Wsizeof-array-div) warns about the calculation
to determine the number of u32's in an array of unsigned longs.
Suppress warning by adding parentheses.

While looking at the above issue, noticed that the 'address' parameter
to hugetlb_fault_mutex_hash is no longer used.  So, remove it from the
definition and all callers.

No functional change.

Link: http://lkml.kernel.org/r/20190919011847.18400-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz 
Reported-by: Nathan Chancellor 
Reviewed-by: Nathan Chancellor 
Reviewed-by: Davidlohr Bueso 
Reviewed-by: Andrew Morton 
Cc: Nick Desaulniers 
Cc: Ilie Halip 
Cc: David Bolvansky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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