10 Jun, 2020
2 commits
-
Convert comments that reference mmap_sem to reference mmap_lock instead.
[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Vlastimil Babka
Reviewed-by: Daniel Jordan
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Laurent Dufour
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds -
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.The change is generated using coccinelle with the following rule:
// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .
@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Daniel Jordan
Reviewed-by: Laurent Dufour
Reviewed-by: Vlastimil Babka
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds
03 Jun, 2020
2 commits
-
Merge updates from Andrew Morton:
"A few little subsystems and a start of a lot of MM patches.Subsystems affected by this patch series: squashfs, ocfs2, parisc,
vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup,
swap, memcg, pagemap, memory-failure, vmalloc, kasan"* emailed patches from Andrew Morton : (128 commits)
kasan: move kasan_report() into report.c
mm/mm_init.c: report kasan-tag information stored in page->flags
ubsan: entirely disable alignment checks under UBSAN_TRAP
kasan: fix clang compilation warning due to stack protector
x86/mm: remove vmalloc faulting
mm: remove vmalloc_sync_(un)mappings()
x86/mm/32: implement arch_sync_kernel_mappings()
x86/mm/64: implement arch_sync_kernel_mappings()
mm/ioremap: track which page-table levels were modified
mm/vmalloc: track which page-table levels were modified
mm: add functions to track page directory modifications
s390: use __vmalloc_node in stack_alloc
powerpc: use __vmalloc_node in alloc_vm_stack
arm64: use __vmalloc_node in arch_alloc_vmap_stack
mm: remove vmalloc_user_node_flags
mm: switch the test_vmalloc module to use __vmalloc_node
mm: remove __vmalloc_node_flags_caller
mm: remove both instances of __vmalloc_node_flags
mm: remove the prot argument to __vmalloc_node
mm: remove the pgprot argument to __vmalloc
... -
Now, when reading /proc/PID/smaps, the PMD migration entry in page table
is simply ignored. To improve the accuracy of /proc/PID/smaps, its
parsing and processing is added.To test the patch, we run pmbench to eat 400 MB memory in background,
then run /usr/bin/migratepages and `cat /proc/PID/smaps` every second.
The issue as follows can be reproduced within 60 seconds.Before the patch, for the fully populated 400 MB anonymous VMA, some THP
pages under migration may be lost as below.7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0
Size: 409600 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Rss: 407552 kB
Pss: 407552 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 407552 kB
Referenced: 301056 kB
Anonymous: 407552 kB
LazyFree: 0 kB
AnonHugePages: 405504 kB
ShmemPmdMapped: 0 kB
FilePmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
Locked: 0 kB
THPeligible: 1
VmFlags: rd wr mr mw me acAfter the patch, it will be always,
7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0
Size: 409600 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Rss: 409600 kB
Pss: 409600 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 409600 kB
Referenced: 294912 kB
Anonymous: 409600 kB
LazyFree: 0 kB
AnonHugePages: 407552 kB
ShmemPmdMapped: 0 kB
FilePmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
Locked: 0 kB
THPeligible: 1
VmFlags: rd wr mr mw me acSigned-off-by: "Huang, Ying"
Signed-off-by: Andrew Morton
Reviewed-by: Zi Yan
Acked-by: Michal Hocko
Acked-by: Kirill A. Shutemov
Acked-by: Vlastimil Babka
Cc: Andrea Arcangeli
Cc: Alexey Dobriyan
Cc: Konstantin Khlebnikov
Cc: "Jérôme Glisse"
Cc: Yang Shi
Link: http://lkml.kernel.org/r/20200403123059.1846960-1-ying.huang@intel.com
Signed-off-by: Linus Torvalds
02 Jun, 2020
1 commit
-
Pull arm64 updates from Will Deacon:
"A sizeable pile of arm64 updates for 5.8.Summary below, but the big two features are support for Branch Target
Identification and Clang's Shadow Call stack. The latter is currently
arm64-only, but the high-level parts are all in core code so it could
easily be adopted by other architectures pending toolchain supportBranch Target Identification (BTI):
- Support for ARMv8.5-BTI in both user- and kernel-space. This allows
branch targets to limit the types of branch from which they can be
called and additionally prevents branching to arbitrary code,
although kernel support requires a very recent toolchain.- Function annotation via SYM_FUNC_START() so that assembly functions
are wrapped with the relevant "landing pad" instructions.- BPF and vDSO updates to use the new instructions.
- Addition of a new HWCAP and exposure of BTI capability to userspace
via ID register emulation, along with ELF loader support for the
BTI feature in .note.gnu.property.- Non-critical fixes to CFI unwind annotations in the sigreturn
trampoline.Shadow Call Stack (SCS):
- Support for Clang's Shadow Call Stack feature, which reserves
platform register x18 to point at a separate stack for each task
that holds only return addresses. This protects function return
control flow from buffer overruns on the main stack.- Save/restore of x18 across problematic boundaries (user-mode,
hypervisor, EFI, suspend, etc).- Core support for SCS, should other architectures want to use it
too.- SCS overflow checking on context-switch as part of the existing
stack limit check if CONFIG_SCHED_STACK_END_CHECK=y.CPU feature detection:
- Removed numerous "SANITY CHECK" errors when running on a system
with mismatched AArch32 support at EL1. This is primarily a concern
for KVM, which disabled support for 32-bit guests on such a system.- Addition of new ID registers and fields as the architecture has
been extended.Perf and PMU drivers:
- Minor fixes and cleanups to system PMU drivers.
Hardware errata:
- Unify KVM workarounds for VHE and nVHE configurations.
- Sort vendor errata entries in Kconfig.
Secure Monitor Call Calling Convention (SMCCC):
- Update to the latest specification from Arm (v1.2).
- Allow PSCI code to query the SMCCC version.
Software Delegated Exception Interface (SDEI):
- Unexport a bunch of unused symbols.
- Minor fixes to handling of firmware data.
Pointer authentication:
- Add support for dumping the kernel PAC mask in vmcoreinfo so that
the stack can be unwound by tools such as kdump.- Simplification of key initialisation during CPU bringup.
BPF backend:
- Improve immediate generation for logical and add/sub instructions.
vDSO:
- Minor fixes to the linker flags for consistency with other
architectures and support for LLVM's unwinder.- Clean up logic to initialise and map the vDSO into userspace.
ACPI:
- Work around for an ambiguity in the IORT specification relating to
the "num_ids" field.- Support _DMA method for all named components rather than only PCIe
root complexes.- Minor other IORT-related fixes.
Miscellaneous:
- Initialise debug traps early for KGDB and fix KDB cacheflushing
deadlock.- Minor tweaks to early boot state (documentation update, set
TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections).- Refactoring and cleanup"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits)
KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h
KVM: arm64: Check advertised Stage-2 page size capability
arm64/cpufeature: Add get_arm64_ftr_reg_nowarn()
ACPI/IORT: Remove the unused __get_pci_rid()
arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register
arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register
arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register
arm64/cpufeature: Add remaining feature bits in ID_PFR0 register
arm64/cpufeature: Introduce ID_MMFR5 CPU register
arm64/cpufeature: Introduce ID_DFR1 CPU register
arm64/cpufeature: Introduce ID_PFR2 CPU register
arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0
arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register
arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register
arm64: mm: Add asid_gen_match() helper
firmware: smccc: Fix missing prototype warning for arm_smccc_version_init
arm64: vdso: Fix CFI directives in sigreturn trampoline
arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
...
05 May, 2020
1 commit
-
Merge in user support for Branch Target Identification, which narrowly
missed the cut for 5.7 after a late ABI concern.* for-next/bti-user:
arm64: bti: Document behaviour for dynamically linked binaries
arm64: elf: Fix allnoconfig kernel build with !ARCH_USE_GNU_PROPERTY
arm64: BTI: Add Kconfig entry for userspace BTI
mm: smaps: Report arm64 guarded pages in smaps
arm64: mm: Display guarded pages in ptdump
KVM: arm64: BTI: Reset BTYPE when skipping emulated instructions
arm64: BTI: Reset BTYPE when skipping emulated instructions
arm64: traps: Shuffle code to eliminate forward declarations
arm64: unify native/compat instruction skipping
arm64: BTI: Decode BYTPE bits when printing PSTATE
arm64: elf: Enable BTI at exec based on ELF program properties
elf: Allow arch to tweak initial mmap prot flags
arm64: Basic Branch Target Identification support
ELF: Add ELF program property parsing support
ELF: UAPI and Kconfig additions for ELF program properties
23 Apr, 2020
1 commit
-
Remove MPX leftovers in generic code.
Fixes: 45fc24e89b7c ("x86/mpx: remove MPX from arch/x86")
Signed-off-by: Jimmy Assarsson
Signed-off-by: Borislav Petkov
Acked-by: Dave Hansen
Link: https://lkml.kernel.org/r/20200402172507.2786-1-jimmyassarsson@gmail.com
08 Apr, 2020
4 commits
-
It's clearer to just put this inline.
Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200317193201.9924-5-adobriyan@gmail.com
Signed-off-by: Linus Torvalds -
The ppos is a private cursor, just like m->version. Use the canonical
cursor, not a special one.Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200317193201.9924-3-adobriyan@gmail.com
Signed-off-by: Linus Torvalds -
Instead of setting m->version in the show method, set it in m_next(),
where it should be. Also remove the fallback code for failing to find a
vma, or version being zero.Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200317193201.9924-2-adobriyan@gmail.com
Signed-off-by: Linus Torvalds -
Instead of calling vma_stop() from m_start() and m_next(), do its work
in m_stop().Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200317193201.9924-1-adobriyan@gmail.com
Signed-off-by: Linus Torvalds
17 Mar, 2020
1 commit
-
The arm64 Branch Target Identification support is activated by marking
executable pages as guarded pages. Report pages mapped this way in
smaps to aid diagnostics.Signed-off-by: Mark Brown
Signed-off-by: Daniel Kiss
Reviewed-by: Kees Cook
Signed-off-by: Catalin Marinas
04 Feb, 2020
1 commit
-
The pte_hole() callback is called at multiple levels of the page tables.
Code dumping the kernel page tables needs to know what at what depth the
missing entry is. Add this is an extra parameter to pte_hole(). When the
depth isn't know (e.g. processing a vma) then -1 is passed.The depth that is reported is the actual level where the entry is missing
(ignoring any folding that is in place), i.e. any levels where
PTRS_PER_P?D is set to 1 are ignored.Note that depth starts at 0 for a PGD so that PUD/PMD/PTE retain their
natural numbers as levels 2/3/4.Link: http://lkml.kernel.org/r/20191218162402.45610-16-steven.price@arm.com
Signed-off-by: Steven Price
Tested-by: Zong Li
Cc: Albert Ou
Cc: Alexandre Ghiti
Cc: Andy Lutomirski
Cc: Ard Biesheuvel
Cc: Arnd Bergmann
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Catalin Marinas
Cc: Christian Borntraeger
Cc: Dave Hansen
Cc: David S. Miller
Cc: Heiko Carstens
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: James Hogan
Cc: James Morse
Cc: Jerome Glisse
Cc: "Liang, Kan"
Cc: Mark Rutland
Cc: Michael Ellerman
Cc: Paul Burton
Cc: Paul Mackerras
Cc: Paul Walmsley
Cc: Peter Zijlstra
Cc: Ralf Baechle
Cc: Russell King
Cc: Thomas Gleixner
Cc: Vasily Gorbik
Cc: Vineet Gupta
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Sep, 2019
2 commits
-
In preparation for non-shmem THP, this patch adds a few stats and exposes
them in /proc/meminfo, /sys/bus/node/devices//meminfo, and
/proc//task//smaps.This patch is mostly a rewrite of Kirill A. Shutemov's earlier version:
https://lkml.kernel.org/r/20170126115819.58875-5-kirill.shutemov@linux.intel.com/Link: http://lkml.kernel.org/r/20190801184244.3169074-5-songliubraving@fb.com
Signed-off-by: Song Liu
Acked-by: Rik van Riel
Acked-by: Kirill A. Shutemov
Acked-by: Johannes Weiner
Cc: Hillf Danton
Cc: Hugh Dickins
Cc: William Kucharski
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Replace 1 << compound_order(page) with compound_nr(page). Minor
improvements in readability.Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle)
Reviewed-by: Andrew Morton
Reviewed-by: Ira Weiny
Acked-by: Kirill A. Shutemov
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Sep, 2019
2 commits
-
The mm_walk structure currently mixed data and code. Split out the
operations vectors into a new mm_walk_ops structure, and while we are
changing the API also declare the mm_walk structure inside the
walk_page_range and walk_page_vma functions.Based on patch from Linus Torvalds.
Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de
Signed-off-by: Christoph Hellwig
Reviewed-by: Thomas Hellstrom
Reviewed-by: Steven Price
Reviewed-by: Jason Gunthorpe
Signed-off-by: Jason Gunthorpe -
Add a new header for the two handful of users of the walk_page_range /
walk_page_vma interface instead of polluting all users of mm.h with it.Link: https://lore.kernel.org/r/20190828141955.22210-2-hch@lst.de
Signed-off-by: Christoph Hellwig
Reviewed-by: Thomas Hellstrom
Reviewed-by: Steven Price
Reviewed-by: Jason Gunthorpe
Signed-off-by: Jason Gunthorpe
19 Jul, 2019
1 commit
-
Commit 7635d9cbe832 ("mm, thp, proc: report THP eligibility for each
vma") introduced THPeligible bit for processes' smaps. But, when
checking the eligibility for shmem vma, __transparent_hugepage_enabled()
is called to override the result from shmem_huge_enabled(). It may
result in the anonymous vma's THP flag override shmem's. For example,
running a simple test which create THP for shmem, but with anonymous THP
disabled, when reading the process's smaps, it may show:7fc92ec00000-7fc92f000000 rw-s 00000000 00:14 27764 /dev/shm/test
Size: 4096 kB
...
[snip]
...
ShmemPmdMapped: 4096 kB
...
[snip]
...
THPeligible: 0And, /proc/meminfo does show THP allocated and PMD mapped too:
ShmemHugePages: 4096 kB
ShmemPmdMapped: 4096 kBThis doesn't make too much sense. The shmem objects should be treated
separately from anonymous THP. Calling shmem_huge_enabled() with
checking MMF_DISABLE_THP sounds good enough. And, we could skip stack
and dax vma check since we already checked if the vma is shmem already.Also check if vma is suitable for THP by calling
transhuge_vma_suitable().And minor fix to smaps output format and documentation.
Link: http://lkml.kernel.org/r/1560401041-32207-3-git-send-email-yang.shi@linux.alibaba.com
Fixes: 7635d9cbe832 ("mm, thp, proc: report THP eligibility for each vma")
Signed-off-by: Yang Shi
Acked-by: Hugh Dickins
Cc: Kirill A. Shutemov
Cc: Michal Hocko
Cc: Vlastimil Babka
Cc: David Rientjes
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jul, 2019
1 commit
-
Pull HMM updates from Jason Gunthorpe:
"Improvements and bug fixes for the hmm interface in the kernel:- Improve clarity, locking and APIs related to the 'hmm mirror'
feature merged last cycle. In linux-next we now see AMDGPU and
nouveau to be using this API.- Remove old or transitional hmm APIs. These are hold overs from the
past with no users, or APIs that existed only to manage cross tree
conflicts. There are still a few more of these cleanups that didn't
make the merge window cut off.- Improve some core mm APIs:
- export alloc_pages_vma() for driver use
- refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
- refactor duplicative driver code into the core dev_pagemap
struct- Remove hmm wrappers of improved core mm APIs, instead have drivers
use the simplified API directly- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
mm: remove the HMM config option
mm: sort out the DEVICE_PRIVATE Kconfig mess
mm: simplify ZONE_DEVICE page private data
mm: remove hmm_devmem_add
mm: remove hmm_vma_alloc_locked_page
nouveau: use devm_memremap_pages directly
nouveau: use alloc_page_vma directly
PCI/P2PDMA: use the dev_pagemap internal refcount
device-dax: use the dev_pagemap internal refcount
memremap: provide an optional internal refcount in struct dev_pagemap
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
memremap: remove the data field in struct dev_pagemap
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
memremap: lift the devmap_enable manipulation into devm_memremap_pages
memremap: pass a struct dev_pagemap to ->kill and ->cleanup
memremap: move dev_pagemap callbacks into a separate structure
memremap: validate the pagemap type passed to devm_memremap_pages
mm: factor out a devm_request_free_mem_region helper
mm: export alloc_pages_vma
...
13 Jul, 2019
5 commits
-
Report separate components (anon, file, and shmem) for PSS in
smaps_rollup.This helps understand and tune the memory manager behavior in consumer
devices, particularly mobile devices. Many of them (e.g. chromebooks and
Android-based devices) use zram for anon memory, and perform disk reads
for discarded file pages. The difference in latency is large (e.g.
reading a single page from SSD is 30 times slower than decompressing a
zram page on one popular device), thus it is useful to know how much of
the PSS is anon vs. file.All the information is already present in /proc/pid/smaps, but much more
expensive to obtain because of the large size of that procfs entry.This patch also removes a small code duplication in smaps_account, which
would have gotten worse otherwise.Also updated Documentation/filesystems/proc.txt (the smaps section was a
bit stale, and I added a smaps_rollup section) and
Documentation/ABI/testing/procfs-smaps_rollup.[semenzato@chromium.org: v5]
Link: http://lkml.kernel.org/r/20190626234333.44608-1-semenzato@chromium.org
Link: http://lkml.kernel.org/r/20190626180429.174569-1-semenzato@chromium.org
Signed-off-by: Luigi Semenzato
Acked-by: Yu Zhao
Cc: Sonny Rao
Cc: Yu Zhao
Cc: Brian Geffon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do not remain stuck forever if something goes wrong. Using a killable
lock permits cleanup of stuck tasks and simplifies investigation.Replace the only unkillable mmap_sem lock in clear_refs_write().
Link: http://lkml.kernel.org/r/156007493826.3335.5424884725467456239.stgit@buzz
Signed-off-by: Konstantin Khlebnikov
Reviewed-by: Roman Gushchin
Reviewed-by: Cyrill Gorcunov
Reviewed-by: Kirill Tkhai
Acked-by: Michal Hocko
Cc: Alexey Dobriyan
Cc: Al Viro
Cc: Matthew Wilcox
Cc: Michal Koutný
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do not remain stuck forever if something goes wrong. Using a killable
lock permits cleanup of stuck tasks and simplifies investigation.Link: http://lkml.kernel.org/r/156007493638.3335.4872164955523928492.stgit@buzz
Signed-off-by: Konstantin Khlebnikov
Reviewed-by: Roman Gushchin
Reviewed-by: Cyrill Gorcunov
Reviewed-by: Kirill Tkhai
Acked-by: Michal Hocko
Cc: Alexey Dobriyan
Cc: Al Viro
Cc: Matthew Wilcox
Cc: Michal Koutný
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do not remain stuck forever if something goes wrong. Using a killable
lock permits cleanup of stuck tasks and simplifies investigation.Link: http://lkml.kernel.org/r/156007493429.3335.14666825072272692455.stgit@buzz
Signed-off-by: Konstantin Khlebnikov
Reviewed-by: Roman Gushchin
Reviewed-by: Cyrill Gorcunov
Reviewed-by: Kirill Tkhai
Acked-by: Michal Hocko
Cc: Alexey Dobriyan
Cc: Al Viro
Cc: Matthew Wilcox
Cc: Michal Koutný
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do not remain stuck forever if something goes wrong. Using a killable
lock permits cleanup of stuck tasks and simplifies investigation.This function is also used for /proc/pid/smaps.
Link: http://lkml.kernel.org/r/156007493160.3335.14447544314127417266.stgit@buzz
Signed-off-by: Konstantin Khlebnikov
Reviewed-by: Roman Gushchin
Reviewed-by: Cyrill Gorcunov
Reviewed-by: Kirill Tkhai
Acked-by: Michal Hocko
Cc: Alexey Dobriyan
Cc: Al Viro
Cc: Matthew Wilcox
Cc: Michal Koutný
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Jul, 2019
1 commit
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The code hasn't been used since it was added to the tree, and doesn't
appear to actually be usable.Signed-off-by: Christoph Hellwig
Reviewed-by: Jason Gunthorpe
Acked-by: Michal Hocko
Reviewed-by: Dan Williams
Tested-by: Dan Williams
Signed-off-by: Jason Gunthorpe
15 May, 2019
2 commits
-
This updates each existing invalidation to use the correct mmu notifier
event that represent what is happening to the CPU page table. See the
patch which introduced the events to see the rational behind this.Link: http://lkml.kernel.org/r/20190326164747.24405-7-jglisse@redhat.com
Signed-off-by: Jérôme Glisse
Reviewed-by: Ralph Campbell
Reviewed-by: Ira Weiny
Cc: Christian König
Cc: Joonas Lahtinen
Cc: Jani Nikula
Cc: Rodrigo Vivi
Cc: Jan Kara
Cc: Andrea Arcangeli
Cc: Peter Xu
Cc: Felix Kuehling
Cc: Jason Gunthorpe
Cc: Ross Zwisler
Cc: Dan Williams
Cc: Paolo Bonzini
Cc: Radim Krcmar
Cc: Michal Hocko
Cc: Christian Koenig
Cc: John Hubbard
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CPU page table update can happens for many reasons, not only as a result
of a syscall (munmap(), mprotect(), mremap(), madvise(), ...) but also as
a result of kernel activities (memory compression, reclaim, migration,
...).Users of mmu notifier API track changes to the CPU page table and take
specific action for them. While current API only provide range of virtual
address affected by the change, not why the changes is happening.This patchset do the initial mechanical convertion of all the places that
calls mmu_notifier_range_init to also provide the default MMU_NOTIFY_UNMAP
event as well as the vma if it is know (most invalidation happens against
a given vma). Passing down the vma allows the users of mmu notifier to
inspect the new vma page protection.The MMU_NOTIFY_UNMAP is always the safe default as users of mmu notifier
should assume that every for the range is going away when that event
happens. A latter patch do convert mm call path to use a more appropriate
events for each call.This is done as 2 patches so that no call site is forgotten especialy
as it uses this following coccinelle patch:%vm_mm, E3, E4)
...>@@
expression E1, E2, E3, E4;
identifier FN, VMA;
@@
FN(..., struct vm_area_struct *VMA, ...) {
}@@
expression E1, E2, E3, E4;
identifier FN, VMA;
@@
FN(...) {
struct vm_area_struct *VMA;
}@@
expression E1, E2, E3, E4;
identifier FN;
@@
FN(...) {
}
---------------------------------------------------------------------->%Applied with:
spatch --all-includes --sp-file mmu-notifier.spatch fs/proc/task_mmu.c --in-place
spatch --sp-file mmu-notifier.spatch --dir kernel/events/ --in-place
spatch --sp-file mmu-notifier.spatch --dir mm --in-placeLink: http://lkml.kernel.org/r/20190326164747.24405-6-jglisse@redhat.com
Signed-off-by: Jérôme Glisse
Reviewed-by: Ralph Campbell
Reviewed-by: Ira Weiny
Cc: Christian König
Cc: Joonas Lahtinen
Cc: Jani Nikula
Cc: Rodrigo Vivi
Cc: Jan Kara
Cc: Andrea Arcangeli
Cc: Peter Xu
Cc: Felix Kuehling
Cc: Jason Gunthorpe
Cc: Ross Zwisler
Cc: Dan Williams
Cc: Paolo Bonzini
Cc: Radim Krcmar
Cc: Michal Hocko
Cc: Christian Koenig
Cc: John Hubbard
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Apr, 2019
1 commit
-
The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it. Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier. For example in Hugh's post from Jul 2017:https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils
"Not strictly relevant here, but a related note: I was very surprised
to discover, only quite recently, how handle_mm_fault() may be called
without down_read(mmap_sem) - when core dumping. That seems a
misguided optimization to me, which would also be nice to correct"In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs. Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.In order to facilitate the backporting I added "Fixes: 86039bd3b4e6"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm(). The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli
Reported-by: Jann Horn
Suggested-by: Oleg Nesterov
Acked-by: Peter Xu
Reviewed-by: Mike Rapoport
Reviewed-by: Oleg Nesterov
Reviewed-by: Jann Horn
Acked-by: Jason Gunthorpe
Acked-by: Michal Hocko
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Mar, 2019
1 commit
-
Pull rdma updates from Jason Gunthorpe:
"This has been a slightly more active cycle than normal with ongoing
core changes and quite a lot of collected driver updates.- Various driver fixes for bnxt_re, cxgb4, hns, mlx5, pvrdma, rxe
- A new data transfer mode for HFI1 giving higher performance
- Significant functional and bug fix update to the mlx5
On-Demand-Paging MR feature- A chip hang reset recovery system for hns
- Change mm->pinned_vm to an atomic64
- Update bnxt_re to support a new 57500 chip
- A sane netlink 'rdma link add' method for creating rxe devices and
fixing the various unregistration race conditions in rxe's
unregister flow- Allow lookup up objects by an ID over netlink
- Various reworking of the core to driver interface:
- drivers should not assume umem SGLs are in PAGE_SIZE chunks
- ucontext is accessed via udata not other means
- start to make the core code responsible for object memory
allocation
- drivers should convert struct device to struct ib_device via a
helper
- drivers have more tools to avoid use after unregister problems"* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (280 commits)
net/mlx5: ODP support for XRC transport is not enabled by default in FW
IB/hfi1: Close race condition on user context disable and close
RDMA/umem: Revert broken 'off by one' fix
RDMA/umem: minor bug fix in error handling path
RDMA/hns: Use GFP_ATOMIC in hns_roce_v2_modify_qp
cxgb4: kfree mhp after the debug print
IB/rdmavt: Fix concurrency panics in QP post_send and modify to error
IB/rdmavt: Fix loopback send with invalidate ordering
IB/iser: Fix dma_nents type definition
IB/mlx5: Set correct write permissions for implicit ODP MR
bnxt_re: Clean cq for kernel consumers only
RDMA/uverbs: Don't do double free of allocated PD
RDMA: Handle ucontext allocations by IB/core
RDMA/core: Fix a WARN() message
bnxt_re: fix the regression due to changes in alloc_pbl
IB/mlx4: Increase the timeout for CM cache
IB/core: Abort page fault handler silently during owning process exit
IB/mlx5: Validate correct PD before prefetch MR
IB/mlx5: Protect against prefetch of invalid MR
RDMA/uverbs: Store PR pointer before it is overwritten
...
06 Mar, 2019
2 commits
-
Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte. Enable that by passing old pte value as
the arg.Link: http://lkml.kernel.org/r/20190116085035.29729-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V
Cc: Benjamin Herrenschmidt
Cc: Heiko Carstens
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Nicholas Piggin
Cc: Paul Mackerras
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "NestMMU pte upgrade workaround for mprotect", v5.
We can upgrade pte access (R -> RW transition) via mprotect. We need to
make sure we follow the recommended pte update sequence as outlined in
commit bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to
handle nest MMU hang") for such updates. This patch series does that.This patch (of 5):
Some architectures may want to call flush_tlb_range from these helpers.
Link: http://lkml.kernel.org/r/20190116085035.29729-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V
Cc: Nicholas Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Michael Ellerman
Cc: Heiko Carstens
Cc: Martin Schwidefsky
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2019
1 commit
-
The 'pss_locked' field of smaps_rollup was being calculated incorrectly.
It accumulated the current pss everytime a locked VMA was found. Fix
that by adding to 'pss_locked' the same time as that of 'pss' if the vma
being walked is locked.Link: http://lkml.kernel.org/r/20190203065425.14650-1-sspatil@android.com
Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup")
Signed-off-by: Sandeep Patil
Acked-by: Vlastimil Babka
Reviewed-by: Joel Fernandes (Google)
Cc: Alexey Dobriyan
Cc: Daniel Colascione
Cc: [4.14.x, 4.19.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Feb, 2019
1 commit
-
Taking a sleeping lock to _only_ increment a variable is quite the
overkill, and pretty much all users do this. Furthermore, some drivers
(ie: infiniband and scif) that need pinned semantics can go to quite
some trouble to actually delay via workqueue (un)accounting for pinned
pages when not possible to acquire it.By making the counter atomic we no longer need to hold the mmap_sem and
can simply some code around it for pinned_vm users. The counter is 64-bit
such that we need not worry about overflows such as rdma user input
controlled from userspace.Reviewed-by: Ira Weiny
Reviewed-by: Christoph Lameter
Reviewed-by: Daniel Jordan
Reviewed-by: Jan Kara
Signed-off-by: Davidlohr Bueso
Signed-off-by: Jason Gunthorpe
29 Dec, 2018
2 commits
-
Userspace falls short when trying to find out whether a specific memory
range is eligible for THP. There are usecases that would like to know
that
http://lkml.kernel.org/r/alpine.DEB.2.21.1809251248450.50347@chino.kir.corp.google.com
: This is used to identify heap mappings that should be able to fault thp
: but do not, and they normally point to a low-on-memory or fragmentation
: issue.The only way to deduce this now is to query for hg resp. nh flags and
confronting the state with the global setting. Except that there is also
PR_SET_THP_DISABLE that might change the picture. So the final logic is
not trivial. Moreover the eligibility of the vma depends on the type of
VMA as well. In the past we have supported only anononymous memory VMAs
but things have changed and shmem based vmas are supported as well these
days and the query logic gets even more complicated because the
eligibility depends on the mount option and another global configuration
knob.Simplify the current state and report the THP eligibility in
/proc//smaps for each existing vma. Reuse
transparent_hugepage_enabled for this purpose. The original
implementation of this function assumes that the caller knows that the vma
itself is supported for THP so make the core checks into
__transparent_hugepage_enabled and use it for existing callers.
__show_smap just use the new transparent_hugepage_enabled which also
checks the vma support status (please note that this one has to be out of
line due to include dependency issues).[mhocko@kernel.org: fix oops with NULL ->f_mapping]
Link: http://lkml.kernel.org/r/20181224185106.GC16738@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20181211143641.3503-3-mhocko@kernel.org
Signed-off-by: Michal Hocko
Acked-by: Vlastimil Babka
Cc: Dan Williams
Cc: David Rientjes
Cc: Jan Kara
Cc: Mike Rapoport
Cc: Paul Oppenheimer
Cc: William Kucharski
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To avoid having to change many call sites everytime we want to add a
parameter use a structure to group all parameters for the mmu_notifier
invalidate_range_start/end cakks. No functional changes with this patch.[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/20181205053628.3210-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse
Acked-by: Christian König
Acked-by: Jan Kara
Cc: Matthew Wilcox
Cc: Ross Zwisler
Cc: Dan Williams
Cc: Paolo Bonzini
Cc: Radim Krcmar
Cc: Michal Hocko
Cc: Felix Kuehling
Cc: Ralph Campbell
Cc: John Hubbard
From: Jérôme Glisse
Subject: mm/mmu_notifier: use structure for invalidate_range_start/end calls v3fix build warning in migrate.c when CONFIG_MMU_NOTIFIER=n
Link: http://lkml.kernel.org/r/20181213171330.8489-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2018
1 commit
-
Pull XArray conversion from Matthew Wilcox:
"The XArray provides an improved interface to the radix tree data
structure, providing locking as part of the API, specifying GFP flags
at allocation time, eliminating preloading, less re-walking the tree,
more efficient iterations and not exposing RCU-protected pointers to
its users.This patch set
1. Introduces the XArray implementation
2. Converts the pagecache to use it
3. Converts memremap to use it
The page cache is the most complex and important user of the radix
tree, so converting it was most important. Converting the memremap
code removes the only other user of the multiorder code, which allows
us to remove the radix tree code that supported it.I have 40+ followup patches to convert many other users of the radix
tree over to the XArray, but I'd like to get this part in first. The
other conversions haven't been in linux-next and aren't suitable for
applying yet, but you can see them in the xarray-conv branch if you're
interested"* 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits)
radix tree: Remove multiorder support
radix tree test: Convert multiorder tests to XArray
radix tree tests: Convert item_delete_rcu to XArray
radix tree tests: Convert item_kill_tree to XArray
radix tree tests: Move item_insert_order
radix tree test suite: Remove multiorder benchmarking
radix tree test suite: Remove __item_insert
memremap: Convert to XArray
xarray: Add range store functionality
xarray: Move multiorder_check to in-kernel tests
xarray: Move multiorder_shrink to kernel tests
xarray: Move multiorder account test in-kernel
radix tree test suite: Convert iteration test to XArray
radix tree test suite: Convert tag_tagged_items to XArray
radix tree: Remove radix_tree_clear_tags
radix tree: Remove radix_tree_maybe_preload_order
radix tree: Remove split/join code
radix tree: Remove radix_tree_update_node_t
page cache: Finish XArray conversion
dax: Convert page fault handlers to XArray
...
27 Oct, 2018
1 commit
-
Leonardo reports an apparent regression in 4.19-rc7:
BUG: unable to handle kernel NULL pointer dereference at 00000000000000f0
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 3 PID: 6032 Comm: python Not tainted 4.19.0-041900rc7-lowlatency #201810071631
Hardware name: LENOVO 80UG/Toronto 4A2, BIOS 0XCN45WW 08/09/2018
RIP: 0010:smaps_pte_range+0x32d/0x540
Code: 80 00 00 00 00 74 a9 48 89 de 41 f6 40 52 40 0f 85 04 02 00 00 49 2b 30 48 c1 ee 0c 49 03 b0 98 00 00 00 49 8b 80 a0 00 00 00 8b b8 f0 00 00 00 e8 b7 ef ec ff 48 85 c0 0f 84 71 ff ff ff a8
RSP: 0018:ffffb0cbc484fb88 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000560ddb9e9000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000560ddb9e9 RDI: 0000000000000001
RBP: ffffb0cbc484fbc0 R08: ffff94a5a227a578 R09: ffff94a5a227a578
R10: 0000000000000000 R11: 0000560ddbbe7000 R12: ffffe903098ba728
R13: ffffb0cbc484fc78 R14: ffffb0cbc484fcf8 R15: ffff94a5a2e9cf48
FS: 00007f6dfb683740(0000) GS:ffff94a5aaf80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000f0 CR3: 000000011c118001 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__walk_page_range+0x3c2/0x6f0
walk_page_vma+0x42/0x60
smap_gather_stats+0x79/0xe0
? gather_pte_stats+0x320/0x320
? gather_hugetlb_stats+0x70/0x70
show_smaps_rollup+0xcd/0x1c0
seq_read+0x157/0x400
__vfs_read+0x3a/0x180
? security_file_permission+0x93/0xc0
? security_file_permission+0x93/0xc0
vfs_read+0x8f/0x140
ksys_read+0x55/0xc0
__x64_sys_read+0x1a/0x20
do_syscall_64+0x5a/0x110
entry_SYSCALL_64_after_hwframe+0x44/0xa9Decoded code matched to local compilation+disassembly points to
smaps_pte_entry():} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
&& pte_none(*pte))) {
page = find_get_entry(vma->vm_file->f_mapping,
linear_page_index(vma, addr));Here, vma->vm_file is NULL. mss->check_shmem_swap should be false in that
case, however for smaps_rollup, smap_gather_stats() can set the flag true
for one vma and leave it true for subsequent vma's where it should be
false.To fix, reset the check_shmem_swap flag to false. There's also related
bug which sets mss->swap to shmem_swapped, which in the context of
smaps_rollup overwrites any value accumulated from previous vma's. Fix
that as well.Note that the report suggests a regression between 4.17.19 and 4.19-rc7,
which makes the 4.19 series ending with commit 258f669e7e88 ("mm:
/proc/pid/smaps_rollup: convert to single value seq_file") suspicious.
But the mss was reused for rollup since 493b0e9d945f ("mm: add
/proc/pid/smaps_rollup") so let's play it safe with the stable backport.Link: http://lkml.kernel.org/r/555fbd1f-4ac9-0b58-dcd4-5dc4380ff7ca@suse.cz
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201377
Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup")
Signed-off-by: Vlastimil Babka
Reported-by: Leonardo Soares Müller
Tested-by: Leonardo Soares Müller
Cc: Greg Kroah-Hartman
Cc: Daniel Colascione
Cc: Alexey Dobriyan
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Sep, 2018
1 commit
-
Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries. This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry). It is also a change in emphasis; exceptional entries are
intimidating and different. As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.Signed-off-by: Matthew Wilcox
Reviewed-by: Josef Bacik
23 Aug, 2018
2 commits
-
The /proc/pid/smaps_rollup file is currently implemented via the
m_start/m_next/m_stop seq_file iterators shared with the other maps files,
that iterate over vma's. However, the rollup file doesn't print anything
for each vma, only accumulate the stats.There are some issues with the current code as reported in [1] - the
accumulated stats can get skewed if seq_file start()/stop() op is called
multiple times, if show() is called multiple times, and after seeks to
non-zero position.Patch [1] fixed those within existing design, but I believe it is
fundamentally wrong to expose the vma iterators to the seq_file mechanism
when smaps_rollup shows logically a single set of values for the whole
address space.This patch thus refactors the code to provide a single "value" at offset
0, with vma iteration to gather the stats done internally. This fixes the
situations where results are skewed, and simplifies the code, especially
in show_smap(), at the expense of somewhat less code reuse.[1] https://marc.info/?l=linux-mm&m=151927723128134&w=2
[vbabka@suse.c: use seq_file infrastructure]
Link: http://lkml.kernel.org/r/bf4525b0-fd5b-4c4c-2cb3-adee3dd95a48@suse.cz
Link: http://lkml.kernel.org/r/20180723111933.15443-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka
Reported-by: Daniel Colascione
Reviewed-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To prepare for handling /proc/pid/smaps_rollup differently from
/proc/pid/smaps factor out from show_smap() printing the parts of output
that are common for both variants, which is the bulk of the gathered
memory stats.[vbabka@suse.cz: add const, per Alexey]
Link: http://lkml.kernel.org/r/b45f319f-cd04-337b-37f8-77f99786aa8a@suse.cz
Link: http://lkml.kernel.org/r/20180723111933.15443-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka
Reviewed-by: Alexey Dobriyan
Cc: Daniel Colascione
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds