linux.git/mm/Kconfig, branch v4.16

mm: relax deferred struct page requirements

2018-02-01T01:18:36+00:00

There is no need to have ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT, as all
the page initialization code is in common code.

Also, there is no need to depend on MEMORY_HOTPLUG, as initialization
code does not really use hotplug memory functionality.  So, we can
remove this requirement as well.

This patch allows to use deferred struct page initialization on all
platforms with memblock allocator.

Tested on x86, arm64, and sparc.  Also, verified that code compiles on
PPC with CONFIG_MEMORY_HOTPLUG disabled.

Link: http://lkml.kernel.org/r/20171117014601.31606-1-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin 
Acked-by: Heiko Carstens 	[s390]
Reviewed-by: Khalid Aziz 
Acked-by: Michael Ellerman 
Acked-by: Michal Hocko 
Cc: Steven Sistare 
Cc: Daniel Jordan 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Kirill A. Shutemov 
Cc: Reza Arbab 
Cc: Martin Schwidefsky 
Cc: Thomas Gleixner 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: add infrastructure for get_user_pages_fast() benchmarking

2017-11-18T00:10:04+00:00

Performance of get_user_pages_fast() is critical for some workloads, but
it's tricky to test it directly.

This patch provides /sys/kernel/debug/gup_benchmark that helps with
testing performance of it.

See tools/testing/selftests/vm/gup_benchmark.c for userspace
counterpart.

Link: http://lkml.kernel.org/r/20170908215603.9189-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov 
Cc: Shuah Khan 
Cc: Ingo Molnar 
Cc: Thorsten Leemhuis 
Cc: Jonathan Corbet 
Cc: Huang Ying 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hmm: avoid bloating arch that do not make use of HMM

2017-09-09T01:26:46+00:00

This moves all new code including new page migration helper behind kernel
Kconfig option so that there is no codee bloat for arch or user that do
not want to use HMM or any of its associated features.

arm allyesconfig (without all the patchset, then with and this patch):
   text	   data	    bss	    dec	    hex	filename
83721896	46511131	27582964	157815991	96814b7	../without/vmlinux
83722364	46511131	27582964	157816459	968168b	vmlinux

[jglisse@redhat.com: struct hmm is only use by HMM mirror functionality]
  Link: http://lkml.kernel.org/r/20170825213133.27286-1-jglisse@redhat.com
[sfr@canb.auug.org.au: fix build (arm multi_v7_defconfig)]
  Link: http://lkml.kernel.org/r/20170828181849.323ab81b@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170818032858.7447-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Signed-off-by: Stephen Rothwell 
Cc: Dan Williams 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/device-public-memory: device memory cache coherent with CPU

2017-09-09T01:26:46+00:00

Platform with advance system bus (like CAPI or CCIX) allow device memory
to be accessible from CPU in a cache coherent fashion.  Add a new type of
ZONE_DEVICE to represent such memory.  The use case are the same as for
the un-addressable device memory but without all the corners cases.

Link: http://lkml.kernel.org/r/20170817000548.32038-19-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Cc: Aneesh Kumar 
Cc: Paul E. McKenney 
Cc: Benjamin Herrenschmidt 
Cc: Dan Williams 
Cc: Ross Zwisler 
Cc: Balbir Singh 
Cc: David Nellans 
Cc: Evgeny Baskakov 
Cc: Johannes Weiner 
Cc: John Hubbard 
Cc: Kirill A. Shutemov 
Cc: Mark Hairgrove 
Cc: Michal Hocko 
Cc: Sherry Cheung 
Cc: Subhash Gutti 
Cc: Vladimir Davydov 
Cc: Bob Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory

2017-09-09T01:26:46+00:00

HMM (heterogeneous memory management) need struct page to support
migration from system main memory to device memory.  Reasons for HMM and
migration to device memory is explained with HMM core patch.

This patch deals with device memory that is un-addressable memory (ie CPU
can not access it).  Hence we do not want those struct page to be manage
like regular memory.  That is why we extend ZONE_DEVICE to support
different types of memory.

A persistent memory type is define for existing user of ZONE_DEVICE and a
new device un-addressable type is added for the un-addressable memory
type.  There is a clear separation between what is expected from each
memory type and existing user of ZONE_DEVICE are un-affected by new
requirement and new use of the un-addressable type.  All specific code
path are protect with test against the memory type.

Because memory is un-addressable we use a new special swap type for when a
page is migrated to device memory (this reduces the number of maximum swap
file).

The main two additions beside memory type to ZONE_DEVICE is two callbacks.
First one, page_free() is call whenever page refcount reach 1 (which
means the page is free as ZONE_DEVICE page never reach a refcount of 0).
This allow device driver to manage its memory and associated struct page.

The second callback page_fault() happens when there is a CPU access to an
address that is back by a device page (which are un-addressable by the
CPU).  This callback is responsible to migrate the page back to system
main memory.  Device driver can not block migration back to system memory,
HMM make sure that such page can not be pin into device memory.

If device is in some error condition and can not migrate memory back then
a CPU page fault to device memory should end with SIGBUS.

[arnd@arndb.de: fix warning]
  Link: http://lkml.kernel.org/r/20170823133213.712917-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170817000548.32038-8-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Signed-off-by: Arnd Bergmann 
Acked-by: Dan Williams 
Cc: Ross Zwisler 
Cc: Aneesh Kumar 
Cc: Balbir Singh 
Cc: Benjamin Herrenschmidt 
Cc: David Nellans 
Cc: Evgeny Baskakov 
Cc: Johannes Weiner 
Cc: John Hubbard 
Cc: Kirill A. Shutemov 
Cc: Mark Hairgrove 
Cc: Michal Hocko 
Cc: Paul E. McKenney 
Cc: Sherry Cheung 
Cc: Subhash Gutti 
Cc: Vladimir Davydov 
Cc: Bob Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hmm/mirror: mirror process address space on device with HMM helpers

2017-09-09T01:26:45+00:00

This is a heterogeneous memory management (HMM) process address space
mirroring.  In a nutshell this provide an API to mirror process address
space on a device.  This boils down to keeping CPU and device page table
synchronize (we assume that both device and CPU are cache coherent like
PCIe device can be).

This patch provide a simple API for device driver to achieve address space
mirroring thus avoiding each device driver to grow its own CPU page table
walker and its own CPU page table synchronization mechanism.

This is useful for NVidia GPU >= Pascal, Mellanox IB >= mlx5 and more
hardware in the future.

[jglisse@redhat.com: fix hmm for "mmu_notifier kill invalidate_page callback"]
  Link: http://lkml.kernel.org/r/20170830231955.GD9445@redhat.com
Link: http://lkml.kernel.org/r/20170817000548.32038-4-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Signed-off-by: Evgeny Baskakov 
Signed-off-by: John Hubbard 
Signed-off-by: Mark Hairgrove 
Signed-off-by: Sherry Cheung 
Signed-off-by: Subhash Gutti 
Cc: Aneesh Kumar 
Cc: Balbir Singh 
Cc: Benjamin Herrenschmidt 
Cc: Dan Williams 
Cc: David Nellans 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Paul E. McKenney 
Cc: Ross Zwisler 
Cc: Vladimir Davydov 
Cc: Bob Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hmm: heterogeneous memory management (HMM for short)

2017-09-09T01:26:45+00:00

HMM provides 3 separate types of functionality:
    - Mirroring: synchronize CPU page table and device page table
    - Device memory: allocating struct page for device memory
    - Migration: migrating regular memory to device memory

This patch introduces some common helpers and definitions to all of
those 3 functionality.

Link: http://lkml.kernel.org/r/20170817000548.32038-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Signed-off-by: Evgeny Baskakov 
Signed-off-by: John Hubbard 
Signed-off-by: Mark Hairgrove 
Signed-off-by: Sherry Cheung 
Signed-off-by: Subhash Gutti 
Cc: Aneesh Kumar 
Cc: Balbir Singh 
Cc: Benjamin Herrenschmidt 
Cc: Dan Williams 
Cc: David Nellans 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Paul E. McKenney 
Cc: Ross Zwisler 
Cc: Vladimir Davydov 
Cc: Bob Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION

2017-09-09T01:26:45+00:00

Introduce CONFIG_ARCH_ENABLE_THP_MIGRATION to limit thp migration
functionality to x86_64, which should be safer at the first step.

Link: http://lkml.kernel.org/r/20170717193955.20207-5-zi.yan@sent.com
Signed-off-by: Naoya Horiguchi 
Signed-off-by: Zi Yan 
Reviewed-by: Anshuman Khandual 
Cc: "H. Peter Anvin" 
Cc: Dave Hansen 
Cc: David Nellans 
Cc: Ingo Molnar 
Cc: Kirill A. Shutemov 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Cc: Andrea Arcangeli 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups

2017-09-07T00:27:29+00:00

devm_memremap_pages() records mapped ranges in pgmap_radix with an entry
per section's worth of memory (128MB).  The key for each of those
entries is a section number.

This leads to false positives when devm_memremap_pages() is passed a
section-unaligned range as lookups in the misalignment fail to return
NULL.  We can close this hole by using the pfn as the key for entries in
the tree.  The number of entries required to describe a remapped range
is reduced by leveraging multi-order entries.

In practice this approach usually yields just one entry in the tree if
the size and starting address are of the same power-of-2 alignment.
Previously we always needed nr_entries = mapping_size / 128MB.

Link: https://lists.01.org/pipermail/linux-nvdimm/2016-August/006666.html
Link: http://lkml.kernel.org/r/150215410565.39310.13767886055248249438.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams 
Reported-by: Toshi Kani 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/kasan: add support for memory hotplug

2017-07-10T23:32:33+00:00

KASAN doesn't happen work with memory hotplug because hotplugged memory
doesn't have any shadow memory.  So any access to hotplugged memory
would cause a crash on shadow check.

Use memory hotplug notifier to allocate and map shadow memory when the
hotplugged memory is going online and free shadow after the memory
offlined.

Link: http://lkml.kernel.org/r/20170601162338.23540-4-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin 
Cc: "H. Peter Anvin" 
Cc: Alexander Potapenko 
Cc: Catalin Marinas 
Cc: Dmitry Vyukov 
Cc: Ingo Molnar 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds