Commit Graph

403 Commits

Author SHA1 Message Date
Christoph Hellwig d45d464b11 mm/hmm: merge hmm_range_snapshot into hmm_range_fault
Add a HMM_FAULT_SNAPSHOT flag so that hmm_range_snapshot can be merged
into the almost identical hmm_range_fault function.

Link: https://lore.kernel.org/r/20190726005650.2566-5-rcampbell@nvidia.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-26 11:10:53 -03:00
Christoph Hellwig 2bcbeaefde mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}
We should not have two different error codes for the same
condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry
case and signals to the caller that the mmap_sem has been unlocked.

Use EBUSY for the !valid case so that callers can get the locking right.

Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.de
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
[jgg: elaborated commit message]
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-25 16:14:39 -03:00
Jonathan Corbet 48ffc3d12b Merge branch 'pdf_fixes_v1' of https://git.linuxtv.org/mchehab/experimental into mauro
Bring in a set of post-thrashup fixes from Mauro.
2019-07-22 13:51:20 -06:00
Dan Williams a0653406a3 mm: document ZONE_DEVICE memory-model implications
Explain the general mechanisms of 'ZONE_DEVICE' pages and list the users
of 'devm_memremap_pages()'.

[dan.j.williams@intel.com: update ZONE_DEVICE memory model documentation]
  Link: http://lkml.kernel.org/r/156109575458.1409767.1885676287099277666.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/156092354985.979959.15763234410543451710.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
Mauro Carvalho Chehab 9fc3a18a94 docs: remove extra conf.py files
Now that the latex_documents are handled automatically, we can
remove those extra conf.py files.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-17 06:57:52 -03:00
Mauro Carvalho Chehab da82c92f11 docs: cgroup-v1: add it to the admin-guide book
Those files belong to the admin guide, so add them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:02 -03:00
Mauro Carvalho Chehab 5704324702 docs: admin-guide: move sysctl directory to it
The stuff under sysctl describes /sys interface from userspace
point of view. So, add it to the admin-guide and remove the
:orphan: from its index file.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:01 -03:00
Mauro Carvalho Chehab 53b9537509 docs: sysctl: convert to ReST
Rename the /proc/sys/ documentation files to ReST, using the
README file as a template for an index.rst, adding the other
files there via TOC markup.

Despite being written on different times with different
styles, try to make them somewhat coherent with a similar
look and feel, ensuring that they'll look nice as both
raw text file and as via the html output produced by the
Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 09:20:26 -03:00
Linus Torvalds fec88ab0af HMM patches for 5.3
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
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

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
  ...
2019-07-14 19:42:11 -07:00
Linus Torvalds e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Linus Torvalds 92c1d65221 Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Documentation updates and the addition of cgroup_parse_float() which
  will be used by new controllers including blk-iocost"

* 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  docs: cgroup-v1: convert docs to ReST and rename to *.rst
  cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS
  cgroup: add cgroup_parse_float()
2019-07-08 21:35:12 -07:00
Jason Gunthorpe cc5dfd59e3 Merge branch 'hmm-devmem-cleanup.4' into rdma.git hmm
Christoph Hellwig says:

====================
Below is a series that cleans up the dev_pagemap interface so that it is
more easily usable, which removes the need to wrap it in hmm and thus
allowing to kill a lot of code

Changes since v3:
 - pull in "mm/swap: Fix release_pages() when releasing devmap pages" and
   rebase the other patches on top of that
 - fold the hmm_devmem_add_resource into the DEVICE_PUBLIC memory removal
   patch
 - remove _vm_normal_page as it isn't needed without DEVICE_PUBLIC memory
 - pick up various ACKs

Changes since v2:
 - fix nvdimm kunit build
 - add a new memory type for device dax
 - fix a few issues in intermediate patches that didn't show up in the end
   result
 - incorporate feedback from Michal Hocko, including killing of
   the DEVICE_PUBLIC memory type entirely

Changes since v1:
 - rebase
 - also switch p2pdma to the internal refcount
 - add type checking for pgmap->type
 - rename the migrate method to migrate_to_ram
 - cleanup the altmap_valid flag
 - various tidbits from the reviews
====================

Conflicts resolved by:
 - Keeping Ira's version of the code in swap.c
 - Using the delete for the section in hmm.rst
 - Using the delete for the devmap code in hmm.c and .h

* branch 'hmm-devmem-cleanup.4': (24 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
  ...

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-02 15:10:45 -03:00
Christoph Hellwig eee3ae41b1 mm: remove hmm_devmem_add
There isn't really much value add in the hmm_devmem_add wrapper and
more, as using devm_memremap_pages directly now is just as simple.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-02 14:32:45 -03:00
Valentin Schneider 22aac85739 docs/vm: hwpoison.rst: Fix quote formatting
The asterisks prepended to the quoted text currently get translated to
bullet points, which gets increasingly confusing the smaller your
screen is (when viewing the sphinx output, that is).

Convert the whole quote to a literal block.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-20 14:11:32 -06:00
Mauro Carvalho Chehab d6a3b24762 docs: scheduler: convert docs to ReST and rename to *.rst
In order to prepare to add them to the Kernel API book,
convert the files to ReST format.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:32:18 -06:00
Mauro Carvalho Chehab 99c8b231ae docs: cgroup-v1: convert docs to ReST and rename to *.rst
Convert the cgroup-v1 files to ReST format, in order to
allow a later addition to the admin-guide.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-14 13:29:54 -07:00
Ralph Campbell 2076e5c045 mm/hmm: update HMM documentation
Update the HMM documentation to reflect the latest API and make a few
minor wording changes.

Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-06-06 16:31:40 -03:00
Randy Dunlap 91173c6e18 mm: fix Documentation/vm/hmm.rst Sphinx warnings
Fix Sphinx warnings in Documentation/vm/hmm.rst by using "::" notation and
inserting a blank line.  Also add a missing ';'.

  Documentation/vm/hmm.rst:292: WARNING: Unexpected indentation.
  Documentation/vm/hmm.rst:300: WARNING: Unexpected indentation.

Link: http://lkml.kernel.org/r/c5995359-7c82-4e47-c7be-b58a4dda0953@infradead.org
Fixes: 023a019a9b ("mm/hmm: add default fault flags to avoid the need to pre-fill pfns arrays")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-01 15:51:31 -07:00
Jérôme Glisse 023a019a9b mm/hmm: add default fault flags to avoid the need to pre-fill pfns arrays
The HMM mirror API can be use in two fashions.  The first one where the
HMM user coalesce multiple page faults into one request and set flags per
pfns for of those faults.  The second one where the HMM user want to
pre-fault a range with specific flags.  For the latter one it is a waste
to have the user pre-fill the pfn arrays with a default flags value.

This patch adds a default flags value allowing user to set them for a
range without having to pre-fill the pfn array.

Link: http://lkml.kernel.org/r/20190403193318.16478-8-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:48 -07:00
Jérôme Glisse a3e0d41c2b mm/hmm: improve driver API to work and wait over a range
A common use case for HMM mirror is user trying to mirror a range and
before they could program the hardware it get invalidated by some core mm
event.  Instead of having user re-try right away to mirror the range
provide a completion mechanism for them to wait for any active
invalidation affecting the range.

This also changes how hmm_range_snapshot() and hmm_range_fault() works by
not relying on vma so that we can drop the mmap_sem when waiting and
lookup the vma again on retry.

Link: http://lkml.kernel.org/r/20190403193318.16478-7-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:48 -07:00
Jérôme Glisse 73231612dc mm/hmm: improve and rename hmm_vma_fault() to hmm_range_fault()
Minor optimization around hmm_pte_need_fault().  Rename for consistency
between code, comments and documentation.  Also improves the comments on
all the possible returns values.  Improve the function by returning the
number of populated entries in pfns array.

Link: http://lkml.kernel.org/r/20190403193318.16478-6-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:48 -07:00
Jérôme Glisse 25f23a0c71 mm/hmm: improve and rename hmm_vma_get_pfns() to hmm_range_snapshot()
Rename for consistency between code, comments and documentation.  Also
improves the comments on all the possible returns values.  Improve the
function by returning the number of populated entries in pfns array.

Link: http://lkml.kernel.org/r/20190403193318.16478-5-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:48 -07:00
Ralph Campbell 41f0a9542a docs/vm: Minor editorial changes in the THP and hugetlbfs
Some minor wording changes and typo corrections.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-30 06:34:40 -06:00
Mike Rapoport 7d10bdbd6d docs/vm: add documentation of memory models
Describe what {FLAT,DISCONTIG,SPARSE}MEM are and how they manage to
maintain pfn <-> struct page correspondence.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-30 06:30:01 -06:00
Yang Shi a496696ab5 doc: mm: migration doesn't use FOLL_SPLIT anymore
When demonstrating FOLL_SPLIT in transhuge document, migration is used
as an example.  But, since commit 94723aafb9 ("mm: unclutter THP
migration"), the way of THP migration is totally changed.  FOLL_SPLIT is
not used by migration anymore due to the change.

Remove the obsolete example to avoid confusion.

Cc: Michal Hocko <mhocko@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-19 12:48:06 -06:00
Tobin C. Harding 66e9c46c5c docs: Use reference to link to rst file
Current document includes the path to an RST doc file.  Since this is an
RST file we can make this a link.  Keeps the path as the link title
since that what the original author wrote.

Use reference to link to rst file.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-09 15:21:17 -06:00
Tobin C. Harding cd7198fc95 docs: Use underscore not hyphen in label
sphinx emits warning

       WARNING: undefined label: memory-allocation ...

This seems to be caused by the use of a hyphen in the label name instead
of an underscore.  Using an underscore for the label name and the
reference clears the warning.

Use underscore not hyphen in label and reference.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-01 16:04:01 -07:00
Tobin C. Harding 11ede50059 docs: Add missing colon
sphinx emits warning

       WARNING: Inline emphasis start-string without end-string.

This is caused by a missing colon.

Add missing colon, clearing shpinx build warning.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-01 16:03:45 -07:00
Tobin C. Harding 358b6ba9be docs: Fix SLUB docs typo
There is a minor typo in SLUB documentation.

Fix typo.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-01 16:03:25 -07:00
Linus Torvalds 3868772b99 A fairly normal cycle for documentation stuff. We have a new
document on perf security, more Italian translations, more
 improvements to the memory-management docs, improvements to the
 pathname lookup documentation, and the usual array of smaller
 fixes.
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Merge tag 'docs-5.0' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "A fairly normal cycle for documentation stuff. We have a new document
  on perf security, more Italian translations, more improvements to the
  memory-management docs, improvements to the pathname lookup
  documentation, and the usual array of smaller fixes.

  As is often the case, there are a few reaches outside of
  Documentation/ to adjust kerneldoc comments"

* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
  docs: improve pathname-lookup document structure
  configfs: fix wrong name of struct in documentation
  docs/mm-api: link slab_common.c to "The Slab Cache" section
  slab: make kmem_cache_create{_usercopy} description proper kernel-doc
  doc:process: add links where missing
  docs/core-api: make mm-api.rst more structured
  x86, boot: documentation whitespace fixup
  Documentation: devres: note checking needs when converting
  doc🇮🇹 add some process/* translations
  doc🇮🇹 fixes in process/1.Intro
  Documentation: convert path-lookup from markdown to resturctured text
  Documentation/admin-guide: update admin-guide index.rst
  Documentation/admin-guide: introduce perf-security.rst file
  scripts/kernel-doc: Fix struct and struct field attribute processing
  Documentation: dev-tools: Fix typos in index.rst
  Correct gen_init_cpio tool's documentation
  Document /proc/pid PID reuse behavior
  Documentation: update path-lookup.md for parallel lookups
  Documentation: Use "while" instead of "whilst"
  dmaengine: Add mailing list address to the documentation
  ...
2018-12-29 11:21:49 -08:00
Matthew Wilcox acf0f57a2c Link the memory allocation guide from the MM docs
I just went looking for the memory allocation guide in the MM docs instead
of in the core API.  For the benefit of the next person who makes that
mistake, link to it from the MM docs.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-11-20 09:17:40 -07:00
Jani Nikula 2ac5e38ea4 Merge drm/drm-next into drm-intel-next-queued
Pull in v4.20-rc3 via drm-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2018-11-20 13:14:08 +02:00
Kuo-Hsin Yang 64e3d12f76 mm, drm/i915: mark pinned shmemfs pages as unevictable
The i915 driver uses shmemfs to allocate backing storage for gem
objects. These shmemfs pages can be pinned (increased ref count) by
shmem_read_mapping_page_gfp(). When a lot of pages are pinned, vmscan
wastes a lot of time scanning these pinned pages. In some extreme case,
all pages in the inactive anon lru are pinned, and only the inactive
anon lru is scanned due to inactive_ratio, the system cannot swap and
invokes the oom-killer. Mark these pinned pages as unevictable to speed
up vmscan.

Export pagevec API check_move_unevictable_pages().

This patch was inspired by Chris Wilson's change [1].

[1]: https://patchwork.kernel.org/patch/9768741/

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Kuo-Hsin Yang <vovoy@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com> # mm part
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181106132324.17390-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2018-11-07 15:28:32 +00:00
Aaron Tomlin c5fd3ca06b slub: extend slub debug to handle multiple slabs
Extend the slub_debug syntax to "slub_debug=<flags>[,<slub>]*", where
<slub> may contain an asterisk at the end.  For example, the following
would poison all kmalloc slabs:

	slub_debug=P,kmalloc*

and the following would apply the default flags to all kmalloc and all
block IO slabs:

	slub_debug=,bio*,kmalloc*

Please note that a similar patch was posted by Iliyan Malchev some time
ago but was never merged:

	https://marc.info/?l=linux-mm&m=131283905330474&w=2

Link: http://lkml.kernel.org/r/20180928111139.27962-1-atomlin@redhat.com
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Iliyan Malchev <malchev@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:19 -07:00
Henrik Austad a7ddcea58a Drop all 00-INDEX files from Documentation/
This is a respin with a wider audience (all that get_maintainer returned)
and I know this spams a *lot* of people. Not sure what would be the correct
way, so my apologies for ruining your inbox.

The 00-INDEX files are supposed to give a summary of all files present
in a directory, but these files are horribly out of date and their
usefulness is brought into question. Often a simple "ls" would reveal
the same information as the filenames are generally quite descriptive as
a short introduction to what the file covers (it should not surprise
anyone what Documentation/sched/sched-design-CFS.txt covers)

A few years back it was mentioned that these files were no longer really
needed, and they have since then grown further out of date, so perhaps
it is time to just throw them out.

A short status yields the following _outdated_ 00-INDEX files, first
counter is files listed in 00-INDEX but missing in the directory, last
is files present but not listed in 00-INDEX.

List of outdated 00-INDEX:
Documentation: (4/10)
Documentation/sysctl: (0/1)
Documentation/timers: (1/0)
Documentation/blockdev: (3/1)
Documentation/w1/slaves: (0/1)
Documentation/locking: (0/1)
Documentation/devicetree: (0/5)
Documentation/power: (1/1)
Documentation/powerpc: (0/5)
Documentation/arm: (1/0)
Documentation/x86: (0/9)
Documentation/x86/x86_64: (1/1)
Documentation/scsi: (4/4)
Documentation/filesystems: (2/9)
Documentation/filesystems/nfs: (0/2)
Documentation/cgroup-v1: (0/2)
Documentation/kbuild: (0/4)
Documentation/spi: (1/0)
Documentation/virtual/kvm: (1/0)
Documentation/scheduler: (0/2)
Documentation/fb: (0/1)
Documentation/block: (0/1)
Documentation/networking: (6/37)
Documentation/vm: (1/3)

Then there are 364 subdirectories in Documentation/ with several files that
are missing 00-INDEX alltogether (and another 120 with a single file and no
00-INDEX).

I don't really have an opinion to whether or not we /should/ have 00-INDEX,
but the above 00-INDEX should either be removed or be kept up to date. If
we should keep the files, I can try to keep them updated, but I rather not
if we just want to delete them anyway.

As a starting point, remove all index-files and references to 00-INDEX and
see where the discussion is going.

Signed-off-by: Henrik Austad <henrik@austad.us>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Just-do-it-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: [Almost everybody else]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-09 15:08:58 -06:00
Baoquan He 74f0fc936c docs/vm/hmm.rst: Add missed space
This space missing caused the colour scheme in vim editor messy
after that line. Add it to fix.

Signed-off-by: Baoquan He <bhe@redhat.com>
[ jc: fixed alignment after the changed line ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-31 16:22:12 -06:00
Mike Rapoport ba22931235 docs/vm: move ksm and transhuge from "user" to "internals" section.
After the userspace interface description for KSM and THP was split to
Documentation/admin-guide/mm, the remaining parts belong to the section
describing MM internals.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-29 06:45:55 -06:00
Mike Rapoport 45c9a74f64 docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge
Now that the administrative information for transparent huge pages is
nicely separated, move it to its own page under the admin guide.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-21 09:30:58 -06:00
Mike Rapoport aa00eaa9af docs/vm: transhuge: minor updates
Some formatting changes and addition of a sentence introducing khugepaged

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-21 09:30:51 -06:00
Mike Rapoport 07a83038a3 docs/vm: transhuge: change sections order
so that userspace interface and implementation description will be grouped
together

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-21 09:30:44 -06:00
Huang Ying 8d420f6c27 mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback
Add document for newly added thp_swpout, thp_swpout_fallback fields in
/proc/vmstat.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-10 15:42:42 -06:00
Mike Rapoport 3ecf53e41a docs/vm: move numa_memory_policy.rst to Documentation/admin-guide/mm
The document describes userspace API and as such it belongs to
Documentation/admin-guide/mm

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-08 09:31:31 -06:00
Mike Rapoport 1174bd849c docs/vm: numa_memory_policy: s/Linux memory policy/NUMA memory policy/
The document describes NUMA memory policy and as it is a part of the Linux
documentation it's obvious that this is Linux memory policy. Besides,
"Linux memory policy" may refer to other policies, e.g. memory hotplug
policy, and using term NUMA makes the documentation less ambiguous.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-08 09:31:27 -06:00
Mike Rapoport 42f44d124e docs/vm: numa_memory_policy: formatting and spelling updates
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-05-08 09:31:20 -06:00
Mike Rapoport c9161088e5 docs/vm: ksm: split userspace interface to admin-guide/mm/ksm.rst
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:49 -06:00
Mike Rapoport 8b898fd114 docs/vm: ksm: udpate description of stable_node_{dups,chains}
Remove implementation details from sysfs parameter descriptions.
Also move the paragraph discussing fragmentation issues and their possible
solution to the "Design" section.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:44 -06:00
Mike Rapoport 2a695ca412 docs/vm: ksm: update stable_node_chains_prune_millisecs description
Make the description of stable_node_chains_prune_millisecs sysfs parameter
less implementation aware and add a few words about this parameter in the
"Design" section.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:40 -06:00
Mike Rapoport 6570c785ea docs/vm: ksm: reshuffle text between "sysfs" and "design" sections
The description of "max_page_sharing" sysfs attribute includes lots of
implementation details that more naturally belong in the "Design"
section.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:37 -06:00
Mike Rapoport 064fca37bc docs/vm: ksm: add "Design" section
Include the KSM description from the source code comment, add a subsection
about reverse mapping and include kernel-doc references for KSM data
structures.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:33 -06:00
Mike Rapoport db12c00f13 docs/vm: ksm: (mostly) formatting updates
Aside from the formatting:
* fixed typos
* added section and sub-section headers
* moved ksmd overview after the description of KSM origins

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:19:29 -06:00
Mike Rapoport 1ad1335dc5 docs/admin-guide/mm: start moving here files from Documentation/vm
Several documents in Documentation/vm fit quite well into the "admin/user
guide" category. The documents that don't overload the reader with lots of
implementation details and provide coherent description of certain feature
can be moved to Documentation/admin-guide/mm.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:02:48 -06:00
Mike Rapoport 41ea9dd36b docs/vm: pagemap: change document title
"pagemap from the Userspace Perspective" is not very descriptive for
unaware readers. Since the document describes how to examine a process page
tables, let's title it "Examining Process Page Tables"

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:02:41 -06:00
Mike Rapoport 86207d9a90 docs/vm: pagemap: formatting and spelling updates
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:02:37 -06:00
Mike Rapoport 946280cdfc docs/vm: hugetlbpage: move section about kernel development to hugetlbfs_reserv
The hugetlbpage describes hugetlbfs from the user perspective and newer
hugetlbfs_reserv document targets kernel developers. Hence the section
about hugetlbfs kernel development naturally belongs there.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:02:33 -06:00
Mike Rapoport fde7917fbd docs/vm: hugetlbpage: minor improvements
* fixed mistypes
* added internal cross-references for sections

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:02:28 -06:00
Jonathan Corbet 24844fd339 Merge branch 'mm-rst' into docs-next
Mike Rapoport says:

  These patches convert files in Documentation/vm to ReST format, add an
  initial index and link it to the top level documentation.

  There are no contents changes in the documentation, except few spelling
  fixes. The relatively large diffstat stems from the indentation and
  paragraph wrapping changes.

  I've tried to keep the formatting as consistent as possible, but I could
  miss some places that needed markup and add some markup where it was not
  necessary.

[jc: significant conflicts in vm/hmm.rst]
2018-04-16 14:25:08 -06:00
Mike Rapoport 82381918c4 docs/vm: add index.rst and link MM documentation to top level index
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:15 -06:00
Mike Rapoport ad56b738c5 docs/vm: rename documentation files to .rst
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:15 -06:00
Mike Rapoport 3406bb5c64 docs/vm: zswap.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport 2a05c58bf9 docs/vm: zsmalloc.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport 44bc09eb3e docs/vm: z3fold.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport f9451df221 docs/vm: userfaultfd.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport a5e4da91e0 docs/vm: unevictable-lru.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport 44f380fe90 docs/vm: transhuge.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport 5431998233 docs/vm: swap_numa.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:14 -06:00
Mike Rapoport d18edf52f4 docs/vm: split_page_table_lock: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 0015190af2 docs/vm: soft-dirty.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 0c14398bf2 docs/vm: slub.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport acc9f3a35c docs/vm: remap_file_pages.txt: conert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport f227e04e90 docs/vm: page_owner: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 1b7599b5de docs/vm: page_migration: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 25c3bf8aaf docs/vm: pagemap.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 137b45527e docs/vm: numa: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 4a832588f4 docs/vm: page_frags convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport 8d83d826c2 docs/vm: overcommit-accounting: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:13 -06:00
Mike Rapoport cb5e4376e5 docs/vm: numa_memory_policy.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport 16f9f7f924 docs/vm: mmu_notifier.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport 2fcbc41380 docs/vm: ksm.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport e3f2025a57 docs/vm: idle_page_tracking.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport b53ba58845 docs/vm: hwpoison.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport 88ececc23c docs/vm: hugetlbfs_reserv.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport 148723f711 docs/vm: hugetlbpage.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport aa9f34e5da docs/vm: hmm.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport eeb8a6426e docs/vm: highmem.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:12 -06:00
Mike Rapoport 76b387bd3c docs/vm: frontswap.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:11 -06:00
Mike Rapoport 5ef829e056 docs/vm: cleancache.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:11 -06:00
Mike Rapoport d04f9f5a78 docs/vm: balance: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:11 -06:00
Mike Rapoport 438b8e24d1 docs/vm: active_mm.txt convert to ReST format
Just add a label for cross-referencing and indent the text to make it
``literal``

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:18:11 -06:00
Matthew Wilcox b93b016313 page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root.  Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.

[willy@infradead.org: fix nds32, fs/dax.c]
  Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Jérôme Glisse e8eddfd2d9 Documentation/vm/hmm.txt: typos and syntaxes fixes
This fix typos and syntaxes, thanks to Randy Dunlap for pointing them out
(they were all my faults).

Link: http://lkml.kernel.org/r/20180409151859.4713-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:31 -07:00
Ralph Campbell 76ea470ce4 mm/hmm: documentation editorial update to HMM documentation
Update the documentation for HMM to fix minor typos and phrasing to be a
bit more readable.

Link: http://lkml.kernel.org/r/20180323005527.758-2-jglisse@redhat.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Stephen  Bates <sbates@raithlin.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:30 -07:00
Mike Rapoport 5a5d1a7708 docs/vm: update 00-INDEX
Several files were added to Documentation/vm without updates to 00-INDEX.
Fill in the missing documents

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-03-21 09:10:23 -06:00
Linus Torvalds 255442c938 Documentation updates for 4.16. New stuff includes refcount_t
documentation, errseq documentation, kernel-doc support for nested
 structure definitions, the removal of lots of crufty kernel-doc support for
 unused formats, SPDX tag documentation, the beginnings of a manual for
 subsystem maintainers, and lots of fixes and updates.
 
 As usual, some of the changesets reach outside of Documentation/ to effect
 kerneldoc comment fixes.  It also adds the new LICENSES directory, of which
 Thomas promises I do not need to be the maintainer.
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Merge tag 'docs-4.16' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "Documentation updates for 4.16.

  New stuff includes refcount_t documentation, errseq documentation,
  kernel-doc support for nested structure definitions, the removal of
  lots of crufty kernel-doc support for unused formats, SPDX tag
  documentation, the beginnings of a manual for subsystem maintainers,
  and lots of fixes and updates.

  As usual, some of the changesets reach outside of Documentation/ to
  effect kerneldoc comment fixes. It also adds the new LICENSES
  directory, of which Thomas promises I do not need to be the
  maintainer"

* tag 'docs-4.16' of git://git.lwn.net/linux: (65 commits)
  linux-next: docs-rst: Fix typos in kfigure.py
  linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt
  Documentation: Fix misconversion of #if
  docs: add index entry for networking/msg_zerocopy
  Documentation: security/credentials.rst: explain need to sort group_list
  LICENSES: Add MPL-1.1 license
  LICENSES: Add the GPL 1.0 license
  LICENSES: Add Linux syscall note exception
  LICENSES: Add the MIT license
  LICENSES: Add the BSD-3-clause "Clear" license
  LICENSES: Add the BSD 3-clause "New" or "Revised" License
  LICENSES: Add the BSD 2-clause "Simplified" license
  LICENSES: Add the LGPL-2.1 license
  LICENSES: Add the LGPL 2.0 license
  LICENSES: Add the GPL 2.0 license
  Documentation: Add license-rules.rst to describe how to properly identify file licenses
  scripts: kernel_doc: better handle show warnings logic
  fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at
  doc: md: Fix a file name to md-fault.c in fault-injection.txt
  errseq: Add to documentation tree
  ...
2018-01-31 19:25:25 -08:00
Roman Gushchin fcb2b0c577 mm: show total hugetlb memory consumption in /proc/meminfo
Currently we display some hugepage statistics (total, free, etc) in
/proc/meminfo, but only for default hugepage size (e.g.  2Mb).

If hugepages of different sizes are used (like 2Mb and 1Gb on x86-64),
/proc/meminfo output can be confusing, as non-default sized hugepages
are not reflected at all, and there are no signs that they are existing
and consuming system memory.

To solve this problem, let's display the total amount of memory,
consumed by hugetlb pages of all sized (both free and used).  Let's call
it "Hugetlb", and display size in kB to match generic /proc/meminfo
style.

For example, (1024 2Mb pages and 2 1Gb pages are pre-allocated):
  $ cat /proc/meminfo
  MemTotal:        8168984 kB
  MemFree:         3789276 kB
  <...>
  CmaFree:               0 kB
  HugePages_Total:    1024
  HugePages_Free:     1024
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:       2048 kB
  Hugetlb:         4194304 kB
  DirectMap4k:       32632 kB
  DirectMap2M:     4161536 kB
  DirectMap1G:     6291456 kB

Also, this patch updates corresponding docs to reflect Hugetlb entry
meaning and difference between Hugetlb and HugePages_Total * Hugepagesize.

Link: http://lkml.kernel.org/r/20171115231409.12131-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:36 -08:00
Masanari Iida 5d87a33782 linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt
This patch fixes an incorrect path for debugfs in hwpoison.txt

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-01-17 16:48:29 -07:00
Srividya Desireddy 51f73fffbf Documentation/vm/zswap.txt: update with same-value filled page feature
Update zswap document with details on same-value filled pages
identification feature.  The usage of zswap.same_filled_pages_enabled
module parameter is explained.

Link: http://lkml.kernel.org/r/20171206114852epcms5p6973b02a9f455d5d3c765eafda0fe2631@epcms5p6
Signed-off-by: Srividya Desireddy <srividya.dr@samsung.com>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14 16:00:48 -08:00
Jérôme Glisse 0f10851ea4 mm/mmu_notifier: avoid double notification when it is useless
This patch only affects users of mmu_notifier->invalidate_range callback
which are device drivers related to ATS/PASID, CAPI, IOMMUv2, SVM ...
and it is an optimization for those users.  Everyone else is unaffected
by it.

When clearing a pte/pmd we are given a choice to notify the event under
the page table lock (notify version of *_clear_flush helpers do call the
mmu_notifier_invalidate_range).  But that notification is not necessary
in all cases.

This patch removes almost all cases where it is useless to have a call
to mmu_notifier_invalidate_range before
mmu_notifier_invalidate_range_end.  It also adds documentation in all
those cases explaining why.

Below is a more in depth analysis of why this is fine to do this:

For secondary TLB (non CPU TLB) like IOMMU TLB or device TLB (when
device use thing like ATS/PASID to get the IOMMU to walk the CPU page
table to access a process virtual address space).  There is only 2 cases
when you need to notify those secondary TLB while holding page table
lock when clearing a pte/pmd:

  A) page backing address is free before mmu_notifier_invalidate_range_end
  B) a page table entry is updated to point to a new page (COW, write fault
     on zero page, __replace_page(), ...)

Case A is obvious you do not want to take the risk for the device to write
to a page that might now be used by something completely different.

Case B is more subtle. For correctness it requires the following sequence
to happen:
  - take page table lock
  - clear page table entry and notify (pmd/pte_huge_clear_flush_notify())
  - set page table entry to point to new page

If clearing the page table entry is not followed by a notify before setting
the new pte/pmd value then you can break memory model like C11 or C++11 for
the device.

Consider the following scenario (device use a feature similar to ATS/
PASID):

Two address addrA and addrB such that |addrA - addrB| >= PAGE_SIZE we
assume they are write protected for COW (other case of B apply too).

[Time N] -----------------------------------------------------------------
CPU-thread-0  {try to write to addrA}
CPU-thread-1  {try to write to addrB}
CPU-thread-2  {}
CPU-thread-3  {}
DEV-thread-0  {read addrA and populate device TLB}
DEV-thread-2  {read addrB and populate device TLB}
[Time N+1] ---------------------------------------------------------------
CPU-thread-0  {COW_step0: {mmu_notifier_invalidate_range_start(addrA)}}
CPU-thread-1  {COW_step0: {mmu_notifier_invalidate_range_start(addrB)}}
CPU-thread-2  {}
CPU-thread-3  {}
DEV-thread-0  {}
DEV-thread-2  {}
[Time N+2] ---------------------------------------------------------------
CPU-thread-0  {COW_step1: {update page table point to new page for addrA}}
CPU-thread-1  {COW_step1: {update page table point to new page for addrB}}
CPU-thread-2  {}
CPU-thread-3  {}
DEV-thread-0  {}
DEV-thread-2  {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0  {preempted}
CPU-thread-1  {preempted}
CPU-thread-2  {write to addrA which is a write to new page}
CPU-thread-3  {}
DEV-thread-0  {}
DEV-thread-2  {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0  {preempted}
CPU-thread-1  {preempted}
CPU-thread-2  {}
CPU-thread-3  {write to addrB which is a write to new page}
DEV-thread-0  {}
DEV-thread-2  {}
[Time N+4] ---------------------------------------------------------------
CPU-thread-0  {preempted}
CPU-thread-1  {COW_step3: {mmu_notifier_invalidate_range_end(addrB)}}
CPU-thread-2  {}
CPU-thread-3  {}
DEV-thread-0  {}
DEV-thread-2  {}
[Time N+5] ---------------------------------------------------------------
CPU-thread-0  {preempted}
CPU-thread-1  {}
CPU-thread-2  {}
CPU-thread-3  {}
DEV-thread-0  {read addrA from old page}
DEV-thread-2  {read addrB from new page}

So here because at time N+2 the clear page table entry was not pair with a
notification to invalidate the secondary TLB, the device see the new value
for addrB before seing the new value for addrA.  This break total memory
ordering for the device.

When changing a pte to write protect or to point to a new write protected
page with same content (KSM) it is ok to delay invalidate_range callback
to mmu_notifier_invalidate_range_end() outside the page table lock.  This
is true even if the thread doing page table update is preempted right
after releasing page table lock before calling
mmu_notifier_invalidate_range_end

Thanks to Andrea for thinking of a problematic scenario for COW.

[jglisse@redhat.com: v2]
  Link: http://lkml.kernel.org/r/20171017031003.7481-2-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170901173011.10745-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:03 -08:00
Jérôme Glisse bffc33ec53 hmm: heterogeneous memory management documentation
Patch series "HMM (Heterogeneous Memory Management)", v25.

Heterogeneous Memory Management (HMM) (description and justification)

Today device driver expose dedicated memory allocation API through their
device file, often relying on a combination of IOCTL and mmap calls.
The device can only access and use memory allocated through this API.
This effectively split the program address space into object allocated
for the device and useable by the device and other regular memory
(malloc, mmap of a file, share memory, â) only accessible by
CPU (or in a very limited way by a device by pinning memory).

Allowing different isolated component of a program to use a device thus
require duplication of the input data structure using device memory
allocator.  This is reasonable for simple data structure (array, grid,
image, â) but this get extremely complex with advance data
structure (list, tree, graph, â) that rely on a web of memory
pointers.  This is becoming a serious limitation on the kind of work
load that can be offloaded to device like GPU.

New industry standard like C++, OpenCL or CUDA are pushing to remove
this barrier.  This require a shared address space between GPU device
and CPU so that GPU can access any memory of a process (while still
obeying memory protection like read only).  This kind of feature is also
appearing in various other operating systems.

HMM is a set of helpers to facilitate several aspects of address space
sharing and device memory management.  Unlike existing sharing mechanism
that rely on pining pages use by a device, HMM relies on mmu_notifier to
propagate CPU page table update to device page table.

Duplicating CPU page table is only one aspect necessary for efficiently
using device like GPU.  GPU local memory have bandwidth in the TeraBytes/
second range but they are connected to main memory through a system bus
like PCIE that is limited to 32GigaBytes/second (PCIE 4.0 16x).  Thus it
is necessary to allow migration of process memory from main system memory
to device memory.  Issue is that on platform that only have PCIE the
device memory is not accessible by the CPU with the same properties as
main memory (cache coherency, atomic operations, ...).

To allow migration from main memory to device memory HMM provides a set of
helper to hotplug device memory as a new type of ZONE_DEVICE memory which
is un-addressable by CPU but still has struct page representing it.  This
allow most of the core kernel logic that deals with a process memory to
stay oblivious of the peculiarity of device memory.

When page backing an address of a process is migrated to device memory the
CPU page table entry is set to a new specific swap entry.  CPU access to
such address triggers a migration back to system memory, just like if the
page was swap on disk.  HMM also blocks any one from pinning a ZONE_DEVICE
page so that it can always be migrated back to system memory if CPU access
it.  Conversely HMM does not migrate to device memory any page that is pin
in system memory.

To allow efficient migration between device memory and main memory a new
migrate_vma() helpers is added with this patchset.  It allows to leverage
device DMA engine to perform the copy operation.

This feature will be use by upstream driver like nouveau mlx5 and probably
other in the future (amdgpu is next suspect in line).  We are actively
working on nouveau and mlx5 support.  To test this patchset we also worked
with NVidia close source driver team, they have more resources than us to
test this kind of infrastructure and also a bigger and better userspace
eco-system with various real industry workload they can be use to test and
profile HMM.

The expected workload is a program builds a data set on the CPU (from
disk, from network, from sensors, â).  Program uses GPU API (OpenCL,
CUDA, ...) to give hint on memory placement for the input data and also
for the output buffer.  Program call GPU API to schedule a GPU job, this
happens using device driver specific ioctl.  All this is hidden from
programmer point of view in case of C++ compiler that transparently
offload some part of a program to GPU.  Program can keep doing other stuff
on the CPU while the GPU is crunching numbers.

It is expected that CPU will not access the same data set as the GPU while
GPU is working on it, but this is not mandatory.  In fact we expect some
small memory object to be actively access by both GPU and CPU concurrently
as synchronization channel and/or for monitoring purposes.  Such object
will stay in system memory and should not be bottlenecked by system bus
bandwidth (rare write and read access from both CPU and GPU).

As we are relying on device driver API, HMM does not introduce any new
syscall nor does it modify any existing ones.  It does not change any
POSIX semantics or behaviors.  For instance the child after a fork of a
process that is using HMM will not be impacted in anyway, nor is there any
data hazard between child COW or parent COW of memory that was migrated to
device prior to fork.

HMM assume a numbers of hardware features.  Device must allow device page
table to be updated at any time (ie device job must be preemptable).
Device page table must provides memory protection such as read only.
Device must track write access (dirty bit).  Device must have a minimum
granularity that match PAGE_SIZE (ie 4k).

Reviewer (just hint):
Patch 1  HMM documentation
Patch 2  introduce core infrastructure and definition of HMM, pretty
         small patch and easy to review
Patch 3  introduce the mirror functionality of HMM, it relies on
         mmu_notifier and thus someone familiar with that part would be
         in better position to review
Patch 4  is an helper to snapshot CPU page table while synchronizing with
         concurrent page table update. Understanding mmu_notifier makes
         review easier.
Patch 5  is mostly a wrapper around handle_mm_fault()
Patch 6  add new add_pages() helper to avoid modifying each arch memory
         hot plug function
Patch 7  add a new memory type for ZONE_DEVICE and also add all the logic
         in various core mm to support this new type. Dan Williams and
         any core mm contributor are best people to review each half of
         this patchset
Patch 8  special case HMM ZONE_DEVICE pages inside put_page() Kirill and
         Dan Williams are best person to review this
Patch 9  allow to uncharge a page from memory group without using the lru
         list field of struct page (best reviewer: Johannes Weiner or
         Vladimir Davydov or Michal Hocko)
Patch 10 Add support to uncharge ZONE_DEVICE page from a memory cgroup (best
         reviewer: Johannes Weiner or Vladimir Davydov or Michal Hocko)
Patch 11 add helper to hotplug un-addressable device memory as new type
         of ZONE_DEVICE memory (new type introducted in patch 3 of this
         serie). This is boiler plate code around memory hotplug and it
         also pick a free range of physical address for the device memory.
         Note that the physical address do not point to anything (at least
         as far as the kernel knows).
Patch 12 introduce a new hmm_device class as an helper for device driver
         that want to expose multiple device memory under a common fake
         device driver. This is usefull for multi-gpu configuration.
         Anyone familiar with device driver infrastructure can review
         this. Boiler plate code really.
Patch 13 add a new migrate mode. Any one familiar with page migration is
         welcome to review.
Patch 14 introduce a new migration helper (migrate_vma()) that allow to
         migrate a range of virtual address of a process using device DMA
         engine to perform the copy. It is not limited to do copy from and
         to device but can also do copy between any kind of source and
         destination memory. Again anyone familiar with migration code
         should be able to verify the logic.
Patch 15 optimize the new migrate_vma() by unmapping pages while we are
         collecting them. This can be review by any mm folks.
Patch 16 add unaddressable memory migration to helper introduced in patch
         7, this can be review by anyone familiar with migration code
Patch 17 add a feature that allow device to allocate non-present page on
         the GPU when migrating a range of address to device memory. This
         is an helper for device driver to avoid having to first allocate
         system memory before migration to device memory
Patch 18 add a new kind of ZONE_DEVICE memory for cache coherent device
         memory (CDM)
Patch 19 add an helper to hotplug CDM memory

Previous patchset posting :
v1 http://lwn.net/Articles/597289/
v2 https://lkml.org/lkml/2014/6/12/559
v3 https://lkml.org/lkml/2014/6/13/633
v4 https://lkml.org/lkml/2014/8/29/423
v5 https://lkml.org/lkml/2014/11/3/759
v6 http://lwn.net/Articles/619737/
v7 http://lwn.net/Articles/627316/
v8 https://lwn.net/Articles/645515/
v9 https://lwn.net/Articles/651553/
v10 https://lwn.net/Articles/654430/
v11 http://www.gossamer-threads.com/lists/linux/kernel/2286424
v12 http://www.kernelhub.org/?msg=972982&p=2
v13 https://lwn.net/Articles/706856/
v14 https://lkml.org/lkml/2016/12/8/344
v15 http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1304107.html
v16 http://www.spinics.net/lists/linux-mm/msg119814.html
v17 https://lkml.org/lkml/2017/1/27/847
v18 https://lkml.org/lkml/2017/3/16/596
v19 https://lkml.org/lkml/2017/4/5/831
v20 https://lwn.net/Articles/720715/
v21 https://lkml.org/lkml/2017/4/24/747
v22 http://lkml.iu.edu/hypermail/linux/kernel/1705.2/05176.html
v23 https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1404788.html
v24 https://lwn.net/Articles/726691/

This patch (of 19):

This adds documentation for HMM (Heterogeneous Memory Management).  It
presents the motivation behind it, the features necessary for it to be
useful and and gives an overview of how this is implemented.

Link: http://lkml.kernel.org/r/20170817000548.32038-2-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sherry Cheung <SCheung@nvidia.com>
Cc: Subhash Gutti <sgutti@nvidia.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Bob Liu <liubo95@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:45 -07:00
Aaron Lu a2468cc9bf swap: choose swap device according to numa node
If the system has more than one swap device and swap device has the node
information, we can make use of this information to decide which swap
device to use in get_swap_pages() to get better performance.

The current code uses a priority based list, swap_avail_list, to decide
which swap device to use and if multiple swap devices share the same
priority, they are used round robin.  This patch changes the previous
single global swap_avail_list into a per-numa-node list, i.e.  for each
numa node, it sees its own priority based list of available swap
devices.  Swap device's priority can be promoted on its matching node's
swap_avail_list.

The current swap device's priority is set as: user can set a >=0 value,
or the system will pick one starting from -1 then downwards.  The
priority value in the swap_avail_list is the negated value of the swap
device's due to plist being sorted from low to high.  The new policy
doesn't change the semantics for priority >=0 cases, the previous
starting from -1 then downwards now becomes starting from -2 then
downwards and -1 is reserved as the promoted value.

Take 4-node EX machine as an example, suppose 4 swap devices are
available, each sit on a different node:
swapA on node 0
swapB on node 1
swapC on node 2
swapD on node 3

After they are all swapped on in the sequence of ABCD.

Current behaviour:
their priorities will be:
swapA: -1
swapB: -2
swapC: -3
swapD: -4
And their position in the global swap_avail_list will be:
swapA   -> swapB   -> swapC   -> swapD
prio:1     prio:2     prio:3     prio:4

New behaviour:
their priorities will be(note that -1 is skipped):
swapA: -2
swapB: -3
swapC: -4
swapD: -5
And their positions in the 4 swap_avail_lists[nid] will be:
swap_avail_lists[0]: /* node 0's available swap device list */
swapA   -> swapB   -> swapC   -> swapD
prio:1     prio:3     prio:4     prio:5
swap_avali_lists[1]: /* node 1's available swap device list */
swapB   -> swapA   -> swapC   -> swapD
prio:1     prio:2     prio:4     prio:5
swap_avail_lists[2]: /* node 2's available swap device list */
swapC   -> swapA   -> swapB   -> swapD
prio:1     prio:2     prio:3     prio:5
swap_avail_lists[3]: /* node 3's available swap device list */
swapD   -> swapA   -> swapB   -> swapC
prio:1     prio:2     prio:3     prio:4

To see the effect of the patch, a test that starts N process, each mmap
a region of anonymous memory and then continually write to it at random
position to trigger both swap in and out is used.

On a 2 node Skylake EP machine with 64GiB memory, two 170GB SSD drives
are used as swap devices with each attached to a different node, the
result is:

runtime=30m/processes=32/total test size=128G/each process mmap region=4G
kernel         throughput
vanilla        13306
auto-binding   15169 +14%

runtime=30m/processes=64/total test size=128G/each process mmap region=2G
kernel         throughput
vanilla        11885
auto-binding   14879 +25%

[aaron.lu@intel.com: v2]
  Link: http://lkml.kernel.org/r/20170814053130.GD2369@aaronlu.sh.intel.com
  Link: http://lkml.kernel.org/r/20170816024439.GA10925@aaronlu.sh.intel.com
[akpm@linux-foundation.org: use kmalloc_array()]
Link: http://lkml.kernel.org/r/20170814053130.GD2369@aaronlu.sh.intel.com
Link: http://lkml.kernel.org/r/20170816024439.GA10925@aaronlu.sh.intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06 17:27:30 -07:00
Michal Hocko c9bff3eebc mm, page_alloc: rip out ZONELIST_ORDER_ZONE
Patch series "cleanup zonelists initialization", v1.

This is aimed at cleaning up the zonelists initialization code we have
but the primary motivation was bug report [2] which got resolved but the
usage of stop_machine is just too ugly to live.  Most patches are
straightforward but 3 of them need a special consideration.

Patch 1 removes zone ordered zonelists completely.  I am CCing linux-api
because this is a user visible change.  As I argue in the patch
description I do not think we have a strong usecase for it these days.
I have kept sysctl in place and warn into the log if somebody tries to
configure zone lists ordering.  If somebody has a real usecase for it we
can revert this patch but I do not expect anybody will actually notice
runtime differences.  This patch is not strictly needed for the rest but
it made patch 6 easier to implement.

Patch 7 removes stop_machine from build_all_zonelists without adding any
special synchronization between iterators and updater which I _believe_
is acceptable as explained in the changelog.  I hope I am not missing
anything.

Patch 8 then removes zonelists_mutex which is kind of ugly as well and
not really needed AFAICS but a care should be taken when double checking
my thinking.

This patch (of 9):

Supporting zone ordered zonelists costs us just a lot of code while the
usefulness is arguable if existent at all.  Mel has already made node
ordering default on 64b systems.  32b systems are still using
ZONELIST_ORDER_ZONE because it is considered better to fallback to a
different NUMA node rather than consume precious lowmem zones.

This argument is, however, weaken by the fact that the memory reclaim
has been reworked to be node rather than zone oriented.  This means that
lowmem requests have to skip over all highmem pages on LRUs already and
so zone ordering doesn't save the reclaim time much.  So the only
advantage of the zone ordering is under a light memory pressure when
highmem requests do not ever hit into lowmem zones and the lowmem
pressure doesn't need to reclaim.

Considering that 32b NUMA systems are rather suboptimal already and it
is generally advisable to use 64b kernel on such a HW I believe we
should rather care about the code maintainability and just get rid of
ZONELIST_ORDER_ZONE altogether.  Keep systcl in place and warn if
somebody tries to set zone ordering either from kernel command line or
the sysctl.

[mhocko@suse.com: reading vm.numa_zonelist_order will never terminate]
Link: http://lkml.kernel.org/r/20170721143915.14161-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06 17:27:25 -07:00