<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/mm.h, branch v4.14.41</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.41</id>
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<updated>2017-12-25T13:26:16Z</updated>
<entry>
<title>x86/mm/64: Rename the register_page_bootmem_memmap() 'size' parameter to 'nr_pages'</title>
<updated>2017-12-25T13:26:16Z</updated>
<author>
<name>Baoquan He</name>
<email>bhe@redhat.com</email>
</author>
<published>2017-10-28T01:30:38Z</published>
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<id>urn:sha1:c60238f5712ba5a7d8391914f8290ae1bf5c08c0</id>
<content type='text'>
commit 15670bfe19905b1dcbb63137f40d718b59d84479 upstream.

register_page_bootmem_memmap()'s 3rd 'size' parameter is named
in a somewhat misleading fashion - rename it to 'nr_pages' which
makes the units of it much clearer.

Meanwhile rename the existing local variable 'nr_pages' to
'nr_pmd_pages', a more expressive name, to avoid conflict with
new function parameter 'nr_pages'.

(Also clean up the unnecessary parentheses in which get_order() is called.)

Signed-off-by: Baoquan He &lt;bhe@redhat.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: akpm@linux-foundation.org
Link: http://lkml.kernel.org/r/1509154238-23250-1-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm: introduce get_user_pages_longterm</title>
<updated>2017-12-05T10:26:28Z</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2017-11-30T00:10:35Z</published>
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<id>urn:sha1:40aa9d2998ca55d9011e75a0fa526ed52e0a4bce</id>
<content type='text'>
commit 2bb6d2837083de722bfdc369cb0d76ce188dd9b4 upstream.

Patch series "introduce get_user_pages_longterm()", v2.

Here is a new get_user_pages api for cases where a driver intends to
keep an elevated page count indefinitely.  This is distinct from usages
like iov_iter_get_pages where the elevated page counts are transient.
The iov_iter_get_pages cases immediately turn around and submit the
pages to a device driver which will put_page when the i/o operation
completes (under kernel control).

In the longterm case userspace is responsible for dropping the page
reference at some undefined point in the future.  This is untenable for
filesystem-dax case where the filesystem is in control of the lifetime
of the block / page and needs reasonable limits on how long it can wait
for pages in a mapping to become idle.

Fixing filesystems to actually wait for dax pages to be idle before
blocks from a truncate/hole-punch operation are repurposed is saved for
a later patch series.

Also, allowing longterm registration of dax mappings is a future patch
series that introduces a "map with lease" semantic where the kernel can
revoke a lease and force userspace to drop its page references.

I have also tagged these for -stable to purposely break cases that might
assume that longterm memory registrations for filesystem-dax mappings
were supported by the kernel.  The behavior regression this policy
change implies is one of the reasons we maintain the "dax enabled.
Warning: EXPERIMENTAL, use at your own risk" notification when mounting
a filesystem in dax mode.

It is worth noting the device-dax interface does not suffer the same
constraints since it does not support file space management operations
like hole-punch.

This patch (of 4):

Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow long standing memory registrations against
filesytem-dax vmas.  Device-dax vmas do not have this problem and are
explicitly allowed.

This is temporary until a "memory registration with layout-lease"
mechanism can be implemented for the affected sub-systems (RDMA and
V4L2).

[akpm@linux-foundation.org: use kcalloc()]
Link: http://lkml.kernel.org/r/151068939435.7446.13560129395419350737.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Suggested-by: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Doug Ledford &lt;dledford@redhat.com&gt;
Cc: Hal Rosenstock &lt;hal.rosenstock@gmail.com&gt;
Cc: Inki Dae &lt;inki.dae@samsung.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Cc: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Cc: Joonyoung Shim &lt;jy0922.shim@samsung.com&gt;
Cc: Kyungmin Park &lt;kyungmin.park@samsung.com&gt;
Cc: Mauro Carvalho Chehab &lt;mchehab@kernel.org&gt;
Cc: Mel Gorman &lt;mgorman@suse.de&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Sean Hefty &lt;sean.hefty@intel.com&gt;
Cc: Seung-Woo Kim &lt;sw0312.kim@samsung.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm, hugetlbfs: introduce -&gt;split() to vm_operations_struct</title>
<updated>2017-12-05T10:26:28Z</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2017-11-30T00:10:28Z</published>
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<id>urn:sha1:c6c78a1d4561880c744d3ec932264b264a879e7c</id>
<content type='text'>
commit 31383c6865a578834dd953d9dbc88e6b19fe3997 upstream.

Patch series "device-dax: fix unaligned munmap handling"

When device-dax is operating in huge-page mode we want it to behave like
hugetlbfs and fail attempts to split vmas into unaligned ranges.  It
would be messy to teach the munmap path about device-dax alignment
constraints in the same (hstate) way that hugetlbfs communicates this
constraint.  Instead, these patches introduce a new -&gt;split() vm
operation.

This patch (of 2):

The device-dax interface has similar constraints as hugetlbfs in that it
requires the munmap path to unmap in huge page aligned units.  Rather
than add more custom vma handling code in __split_vma() introduce a new
vm operation to perform this vma specific check.

Link: http://lkml.kernel.org/r/151130418135.4029.6783191281930729710.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap")
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:07:57Z</published>
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<id>urn:sha1:b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>include/linux/mm.h: fix typo in VM_MPX definition</title>
<updated>2017-10-04T00:54:23Z</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2017-10-03T23:14:24Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fa87b91c94a8fd2c8502b6761be2d08a8e9bcf55'/>
<id>urn:sha1:fa87b91c94a8fd2c8502b6761be2d08a8e9bcf55</id>
<content type='text'>
There's a typo in recent change of VM_MPX definition.  We want it to be
VM_HIGH_ARCH_4, not VM_HIGH_ARCH_BIT_4.

This bug does cause visible regressions.  In arch_vma_name the vmflags
are tested against VM_MPX.  With the incorrect value of VM_MPX, a number
of vmas (such as the stack) test positive and end up being marked as
"[mpx]" in /proc/N/maps instead of their correct names.

This confuses tools like rr which expect to be able to find familiar
vmas.

Fixes: df3735c5b40f ("x86,mpx: make mpx depend on x86-64 to free up VMA flag")
Link: http://lkml.kernel.org/r/20170918140253.36856-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Kyle Huey &lt;me@kylehuey.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[4.14+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>lib/interval_tree: fast overlap detection</title>
<updated>2017-09-09T01:26:49Z</updated>
<author>
<name>Davidlohr Bueso</name>
<email>dave@stgolabs.net</email>
</author>
<published>2017-09-08T23:15:08Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=f808c13fd3738948e10196496959871130612b61'/>
<id>urn:sha1:f808c13fd3738948e10196496959871130612b61</id>
<content type='text'>
Allow interval trees to quickly check for overlaps to avoid unnecesary
tree lookups in interval_tree_iter_first().

As of this patch, all interval tree flavors will require using a
'rb_root_cached' such that we can have the leftmost node easily
available.  While most users will make use of this feature, those with
special functions (in addition to the generic insert, delete, search
calls) will avoid using the cached option as they can do funky things
with insertions -- for example, vma_interval_tree_insert_after().

[jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()]
  Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso &lt;dbueso@suse.de&gt;
Signed-off-by: Jérôme Glisse &lt;jglisse@redhat.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Doug Ledford &lt;dledford@redhat.com&gt;
Acked-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Jason Wang &lt;jasowang@redhat.com&gt;
Cc: Christian Benvenuti &lt;benve@cisco.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/hmm: avoid bloating arch that do not make use of HMM</title>
<updated>2017-09-09T01:26:46Z</updated>
<author>
<name>Jérôme Glisse</name>
<email>jglisse@redhat.com</email>
</author>
<published>2017-09-08T23:12:32Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6b368cd4a44ce95b33f1d31f2f932e6ae707f319'/>
<id>urn:sha1:6b368cd4a44ce95b33f1d31f2f932e6ae707f319</id>
<content type='text'>
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 &lt;jglisse@redhat.com&gt;
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/device-public-memory: device memory cache coherent with CPU</title>
<updated>2017-09-09T01:26:46Z</updated>
<author>
<name>Jérôme Glisse</name>
<email>jglisse@redhat.com</email>
</author>
<published>2017-09-08T23:12:24Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=df6ad69838fc9dcdbee0dcf2fc2c6f1113f8d609'/>
<id>urn:sha1:df6ad69838fc9dcdbee0dcf2fc2c6f1113f8d609</id>
<content type='text'>
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 &lt;jglisse@redhat.com&gt;
Cc: Aneesh Kumar &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Balbir Singh &lt;bsingharora@gmail.com&gt;
Cc: David Nellans &lt;dnellans@nvidia.com&gt;
Cc: Evgeny Baskakov &lt;ebaskakov@nvidia.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Mark Hairgrove &lt;mhairgrove@nvidia.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Sherry Cheung &lt;SCheung@nvidia.com&gt;
Cc: Subhash Gutti &lt;sgutti@nvidia.com&gt;
Cc: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Cc: Bob Liu &lt;liubo95@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/ZONE_DEVICE: special case put_page() for device private pages</title>
<updated>2017-09-09T01:26:46Z</updated>
<author>
<name>Jérôme Glisse</name>
<email>jglisse@redhat.com</email>
</author>
<published>2017-09-08T23:11:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7b2d55d2c8961ae9d456d3133f4ae2f0fbd3e14f'/>
<id>urn:sha1:7b2d55d2c8961ae9d456d3133f4ae2f0fbd3e14f</id>
<content type='text'>
A ZONE_DEVICE page that reach a refcount of 1 is free ie no longer have
any user.  For device private pages this is important to catch and thus we
need to special case put_page() for this.

Link: http://lkml.kernel.org/r/20170817000548.32038-9-jglisse@redhat.com
Signed-off-by: Jérôme Glisse &lt;jglisse@redhat.com&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Aneesh Kumar &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Balbir Singh &lt;bsingharora@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: David Nellans &lt;dnellans@nvidia.com&gt;
Cc: Evgeny Baskakov &lt;ebaskakov@nvidia.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Mark Hairgrove &lt;mhairgrove@nvidia.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Sherry Cheung &lt;SCheung@nvidia.com&gt;
Cc: Subhash Gutti &lt;sgutti@nvidia.com&gt;
Cc: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Cc: Bob Liu &lt;liubo95@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory</title>
<updated>2017-09-09T01:26:46Z</updated>
<author>
<name>Jérôme Glisse</name>
<email>jglisse@redhat.com</email>
</author>
<published>2017-09-08T23:11:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5042db43cc26f51eed51c56192e2c2317e44315f'/>
<id>urn:sha1:5042db43cc26f51eed51c56192e2c2317e44315f</id>
<content type='text'>
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 &lt;jglisse@redhat.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Aneesh Kumar &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Balbir Singh &lt;bsingharora@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: David Nellans &lt;dnellans@nvidia.com&gt;
Cc: Evgeny Baskakov &lt;ebaskakov@nvidia.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Mark Hairgrove &lt;mhairgrove@nvidia.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Sherry Cheung &lt;SCheung@nvidia.com&gt;
Cc: Subhash Gutti &lt;sgutti@nvidia.com&gt;
Cc: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Cc: Bob Liu &lt;liubo95@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
