<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arm64/include/asm/pgtable.h, branch v4.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>arm64: expose number of page table levels on Kconfig level</title>
<updated>2015-04-14T23:49:01+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2015-04-14T22:45:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f25e6ad58e1fb3b4d441e4c55635c4598a6fa94'/>
<id>9f25e6ad58e1fb3b4d441e4c55635c4598a6fa94</id>
<content type='text'>
We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before
sourcing init/Kconfig: arch/Kconfig will define default value and it's
sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before
sourcing init/Kconfig: arch/Kconfig will define default value and it's
sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: enable PTE type bit in the mask for pte_modify</title>
<updated>2015-02-26T18:30:12+00:00</updated>
<author>
<name>Feng Kan</name>
<email>fkan@apm.com</email>
</author>
<published>2015-02-24T23:40:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6910fa16dbe142f6a0fd0fd7c249f9883ff7fc8a'/>
<id>6910fa16dbe142f6a0fd0fd7c249f9883ff7fc8a</id>
<content type='text'>
Caught during Trinity testing. The pte_modify does not allow
modification for PTE type bit. This cause the test to hang
the system. It is found that the PTE can't transit from an
inaccessible page (b00) to a valid page (b11) because the mask
does not allow it. This happens when a big block of mmaped
memory is set the PROT_NONE, then the a small piece is broken
off and set to PROT_WRITE | PROT_READ cause a huge page split.

Signed-off-by: Feng Kan &lt;fkan@apm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Caught during Trinity testing. The pte_modify does not allow
modification for PTE type bit. This cause the test to hang
the system. It is found that the PTE can't transit from an
inaccessible page (b00) to a valid page (b11) because the mask
does not allow it. This happens when a big block of mmaped
memory is set the PROT_NONE, then the a small piece is broken
off and set to PROT_WRITE | PROT_READ cause a huge page split.

Signed-off-by: Feng Kan &lt;fkan@apm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2015-02-12T02:23:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-02-12T02:23:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59d53737a8640482995fea13c6e2c0fd016115d6'/>
<id>59d53737a8640482995fea13c6e2c0fd016115d6</id>
<content type='text'>
Merge second set of updates from Andrew Morton:
 "More of MM"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (83 commits)
  mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
  mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
  vmstat: Reduce time interval to stat update on idle cpu
  mm/page_owner.c: remove unnecessary stack_trace field
  Documentation/filesystems/proc.txt: describe /proc/&lt;pid&gt;/map_files
  mm: incorporate read-only pages into transparent huge pages
  vmstat: do not use deferrable delayed work for vmstat_update
  mm: more aggressive page stealing for UNMOVABLE allocations
  mm: always steal split buddies in fallback allocations
  mm: when stealing freepages, also take pages created by splitting buddy page
  mincore: apply page table walker on do_mincore()
  mm: /proc/pid/clear_refs: avoid split_huge_page()
  mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
  mempolicy: apply page table walker on queue_pages_range()
  arch/powerpc/mm/subpage-prot.c: use walk-&gt;vma and walk_page_vma()
  memcg: cleanup preparation for page table walk
  numa_maps: remove numa_maps-&gt;vma
  numa_maps: fix typo in gather_hugetbl_stats
  pagemap: use walk-&gt;vma instead of calling find_vma()
  clear_refs: remove clear_refs_private-&gt;vma and introduce clear_refs_test_walk()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge second set of updates from Andrew Morton:
 "More of MM"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (83 commits)
  mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
  mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
  vmstat: Reduce time interval to stat update on idle cpu
  mm/page_owner.c: remove unnecessary stack_trace field
  Documentation/filesystems/proc.txt: describe /proc/&lt;pid&gt;/map_files
  mm: incorporate read-only pages into transparent huge pages
  vmstat: do not use deferrable delayed work for vmstat_update
  mm: more aggressive page stealing for UNMOVABLE allocations
  mm: always steal split buddies in fallback allocations
  mm: when stealing freepages, also take pages created by splitting buddy page
  mincore: apply page table walker on do_mincore()
  mm: /proc/pid/clear_refs: avoid split_huge_page()
  mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
  mempolicy: apply page table walker on queue_pages_range()
  arch/powerpc/mm/subpage-prot.c: use walk-&gt;vma and walk_page_vma()
  memcg: cleanup preparation for page table walk
  numa_maps: remove numa_maps-&gt;vma
  numa_maps: fix typo in gather_hugetbl_stats
  pagemap: use walk-&gt;vma instead of calling find_vma()
  clear_refs: remove clear_refs_private-&gt;vma and introduce clear_refs_test_walk()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2015-02-12T02:03:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-02-12T02:03:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b00f7efb5303418c231994c91fb8239f5ada260'/>
<id>6b00f7efb5303418c231994c91fb8239f5ada260</id>
<content type='text'>
Pull arm64 updates from Catalin Marinas:
 "arm64 updates for 3.20:

   - reimplementation of the virtual remapping of UEFI Runtime Services
     in a way that is stable across kexec
   - emulation of the "setend" instruction for 32-bit tasks (user
     endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set
     accordingly)
   - compat_sys_call_table implemented in C (from asm) and made it a
     constant array together with sys_call_table
   - export CPU cache information via /sys (like other architectures)
   - DMA API implementation clean-up in preparation for IOMMU support
   - macros clean-up for KVM
   - dropped some unnecessary cache+tlb maintenance
   - CONFIG_ARM64_CPU_SUSPEND clean-up
   - defconfig update (CPU_IDLE)

  The EFI changes going via the arm64 tree have been acked by Matt
  Fleming.  There is also a patch adding sys_*stat64 prototypes to
  include/linux/syscalls.h, acked by Andrew Morton"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits)
  arm64: compat: Remove incorrect comment in compat_siginfo
  arm64: Fix section mismatch on alloc_init_p[mu]d()
  arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros
  arm64: mm: use *_sect to check for section maps
  arm64: drop unnecessary cache+tlb maintenance
  arm64:mm: free the useless initial page table
  arm64: Enable CPU_IDLE in defconfig
  arm64: kernel: remove ARM64_CPU_SUSPEND config option
  arm64: make sys_call_table const
  arm64: Remove asm/syscalls.h
  arm64: Implement the compat_sys_call_table in C
  syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64
  compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes
  arm64: uapi: expose our struct ucontext to the uapi headers
  smp, ARM64: Kill SMP single function call interrupt
  arm64: Emulate SETEND for AArch32 tasks
  arm64: Consolidate hotplug notifier for instruction emulation
  arm64: Track system support for mixed endian EL0
  arm64: implement generic IOMMU configuration
  arm64: Combine coherent and non-coherent swiotlb dma_ops
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull arm64 updates from Catalin Marinas:
 "arm64 updates for 3.20:

   - reimplementation of the virtual remapping of UEFI Runtime Services
     in a way that is stable across kexec
   - emulation of the "setend" instruction for 32-bit tasks (user
     endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set
     accordingly)
   - compat_sys_call_table implemented in C (from asm) and made it a
     constant array together with sys_call_table
   - export CPU cache information via /sys (like other architectures)
   - DMA API implementation clean-up in preparation for IOMMU support
   - macros clean-up for KVM
   - dropped some unnecessary cache+tlb maintenance
   - CONFIG_ARM64_CPU_SUSPEND clean-up
   - defconfig update (CPU_IDLE)

  The EFI changes going via the arm64 tree have been acked by Matt
  Fleming.  There is also a patch adding sys_*stat64 prototypes to
  include/linux/syscalls.h, acked by Andrew Morton"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits)
  arm64: compat: Remove incorrect comment in compat_siginfo
  arm64: Fix section mismatch on alloc_init_p[mu]d()
  arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros
  arm64: mm: use *_sect to check for section maps
  arm64: drop unnecessary cache+tlb maintenance
  arm64:mm: free the useless initial page table
  arm64: Enable CPU_IDLE in defconfig
  arm64: kernel: remove ARM64_CPU_SUSPEND config option
  arm64: make sys_call_table const
  arm64: Remove asm/syscalls.h
  arm64: Implement the compat_sys_call_table in C
  syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64
  compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes
  arm64: uapi: expose our struct ucontext to the uapi headers
  smp, ARM64: Kill SMP single function call interrupt
  arm64: Emulate SETEND for AArch32 tasks
  arm64: Consolidate hotplug notifier for instruction emulation
  arm64: Track system support for mixed endian EL0
  arm64: implement generic IOMMU configuration
  arm64: Combine coherent and non-coherent swiotlb dma_ops
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: make FIRST_USER_ADDRESS unsigned long on all archs</title>
<updated>2015-02-12T01:06:03+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2015-02-11T23:26:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d016bf7ece53b2b947bfd769e0842fd2feb7556b'/>
<id>d016bf7ece53b2b947bfd769e0842fd2feb7556b</id>
<content type='text'>
LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":

    mm/mmap.c: In function 'exit_mmap':
 &gt;&gt; mm/mmap.c:2857:2: warning: right shift count &gt;= width of type [enabled by default]

The code:

 &gt; 2857                WARN_ON(mm_nr_pmds(mm) &gt;
   2858                                round_up(FIRST_USER_ADDRESS, PUD_SIZE) &gt;&gt; PUD_SHIFT);

In this, on tile, we have FIRST_USER_ADDRESS defined as 0.  round_up() has
the same type -- int.  PUD_SHIFT.

I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long.  On every arch for consistency.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reported-by: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":

    mm/mmap.c: In function 'exit_mmap':
 &gt;&gt; mm/mmap.c:2857:2: warning: right shift count &gt;= width of type [enabled by default]

The code:

 &gt; 2857                WARN_ON(mm_nr_pmds(mm) &gt;
   2858                                round_up(FIRST_USER_ADDRESS, PUD_SIZE) &gt;&gt; PUD_SHIFT);

In this, on tile, we have FIRST_USER_ADDRESS defined as 0.  round_up() has
the same type -- int.  PUD_SHIFT.

I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long.  On every arch for consistency.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reported-by: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: drop PTE_FILE and pte_file()-related helpers</title>
<updated>2015-02-10T22:30:31+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2015-02-10T22:10:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9b3e661e58b90b0c2d5c2168c23408f1e59e9e35'/>
<id>9b3e661e58b90b0c2d5c2168c23408f1e59e9e35</id>
<content type='text'>
We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.

This patch also adjust __SWP_TYPE_SHIFT and increase number of bits
availble for swap offset.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.

This patch also adjust __SWP_TYPE_SHIFT and increase number of bits
availble for swap offset.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64:mm: free the useless initial page table</title>
<updated>2015-01-28T12:07:28+00:00</updated>
<author>
<name>zhichang.yuan</name>
<email>zhichang.yuan@linaro.org</email>
</author>
<published>2014-12-09T07:26:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=523d6e9fae9333a0e2a7baf4d11c8bcca544790e'/>
<id>523d6e9fae9333a0e2a7baf4d11c8bcca544790e</id>
<content type='text'>
For 64K page system, after mapping a PMD section, the corresponding initial
page table is not needed any more. That page can be freed.

Signed-off-by: Zhichang Yuan &lt;zhichang.yuan@linaro.org&gt;
[catalin.marinas@arm.com: added BUG_ON() to catch late memblock freeing]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For 64K page system, after mapping a PMD section, the corresponding initial
page table is not needed any more. That page can be freed.

Signed-off-by: Zhichang Yuan &lt;zhichang.yuan@linaro.org&gt;
[catalin.marinas@arm.com: added BUG_ON() to catch late memblock freeing]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64/mm: add create_pgd_mapping() to create private page tables</title>
<updated>2015-01-12T08:16:52+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2014-10-20T13:42:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8ce837cee8f51fb0eacb32c85461ea2f0fafc9f8'/>
<id>8ce837cee8f51fb0eacb32c85461ea2f0fafc9f8</id>
<content type='text'>
For UEFI, we need to install the memory mappings used for Runtime Services
in a dedicated set of page tables. Add create_pgd_mapping(), which allows
us to allocate and install those page table entries early.

Reviewed-by: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Leif Lindholm &lt;leif.lindholm@linaro.org&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For UEFI, we need to install the memory mappings used for Runtime Services
in a dedicated set of page tables. Add create_pgd_mapping(), which allows
us to allocate and install those page table entries early.

Reviewed-by: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Leif Lindholm &lt;leif.lindholm@linaro.org&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Add pgd_page to support RCU fast_gup</title>
<updated>2014-12-23T16:39:17+00:00</updated>
<author>
<name>Jungseok Lee</name>
<email>jungseoklee85@gmail.com</email>
</author>
<published>2014-12-20T00:49:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d96e0cba26323c3daeb9f7cdfd4efe70985e2c6'/>
<id>5d96e0cba26323c3daeb9f7cdfd4efe70985e2c6</id>
<content type='text'>
This patch adds pgd_page definition in order to keep supporting
HAVE_GENERIC_RCU_GUP configuration. In addition, it changes pud_page
expression to align with pmd_page for readability.

An introduction of pgd_page resolves the following build breakage
under 4KB + 4Level memory management combo.

mm/gup.c: In function 'gup_huge_pgd':
mm/gup.c:889:2: error: implicit declaration of function 'pgd_page' [-Werror=implicit-function-declaration]
  head = pgd_page(orig);
  ^
mm/gup.c:889:7: warning: assignment makes pointer from integer without a cast
  head = pgd_page(orig);

Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Steve Capper &lt;steve.capper@linaro.org&gt;
Signed-off-by: Jungseok Lee &lt;jungseoklee85@gmail.com&gt;
[catalin.marinas@arm.com: remove duplicate pmd_page definition]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch adds pgd_page definition in order to keep supporting
HAVE_GENERIC_RCU_GUP configuration. In addition, it changes pud_page
expression to align with pmd_page for readability.

An introduction of pgd_page resolves the following build breakage
under 4KB + 4Level memory management combo.

mm/gup.c: In function 'gup_huge_pgd':
mm/gup.c:889:2: error: implicit declaration of function 'pgd_page' [-Werror=implicit-function-declaration]
  head = pgd_page(orig);
  ^
mm/gup.c:889:7: warning: assignment makes pointer from integer without a cast
  head = pgd_page(orig);

Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Steve Capper &lt;steve.capper@linaro.org&gt;
Signed-off-by: Jungseok Lee &lt;jungseoklee85@gmail.com&gt;
[catalin.marinas@arm.com: remove duplicate pmd_page definition]
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: fix huge zero page accounting in smaps report</title>
<updated>2014-12-11T01:41:08+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill@shutemov.name</email>
</author>
<published>2014-12-10T23:44:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c164e038eee805147e95789dddb88ae3b3aca11c'/>
<id>c164e038eee805147e95789dddb88ae3b3aca11c</id>
<content type='text'>
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.

For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds.  We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.

Let's add separate codepath to handle pmds.  follow_trans_huge_pmd() will
detect huge zero page for us.

We would need pmd_dirty() helper to do this properly.  The patch adds it
to THP-enabled architectures which don't yet have one.

[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" &lt;kirill@shutemov.name&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Tested-by: Fengwei Yin &lt;yfw.kernel@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
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<pre>
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.

For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds.  We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.

Let's add separate codepath to handle pmds.  follow_trans_huge_pmd() will
detect huge zero page for us.

We would need pmd_dirty() helper to do this properly.  The patch adds it
to THP-enabled architectures which don't yet have one.

[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" &lt;kirill@shutemov.name&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Tested-by: Fengwei Yin &lt;yfw.kernel@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
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