linux.git/Documentation/admin-guide/mm, branch v5.13

memory-hotplug.rst: add a note about ZONE_MOVABLE and page pinning

2021-05-05T18:27:26+00:00

Document the special handling of page pinning when ZONE_MOVABLE present.

Link: https://lkml.kernel.org/r/20210215161349.246722-11-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin 
Suggested-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Dan Williams 
Cc: David Rientjes 
Cc: Ingo Molnar 
Cc: Ira Weiny 
Cc: James Morris 
Cc: Jason Gunthorpe 
Cc: Jason Gunthorpe 
Cc: John Hubbard 
Cc: Joonsoo Kim 
Cc: Matthew Wilcox 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Mike Kravetz 
Cc: Oscar Salvador 
Cc: Peter Zijlstra 
Cc: Sasha Levin 
Cc: Steven Rostedt (VMware) 
Cc: Tyler Hicks 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userfaultfd: update documentation to describe minor fault handling

2021-05-05T18:27:23+00:00

Reword / reorganize things a little bit into "lists", so new features /
modes / ioctls can sort of just be appended.

Describe how UFFDIO_REGISTER_MODE_MINOR and UFFDIO_CONTINUE can be used to
intercept and resolve minor faults.  Make it clear that COPY and ZEROPAGE
are used for MISSING faults, whereas CONTINUE is used for MINOR faults.

Link: https://lkml.kernel.org/r/20210301222728.176417-6-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen 
Reviewed-by: Peter Xu 
Cc: Adam Ruprecht 
Cc: Alexander Viro 
Cc: Alexey Dobriyan 
Cc: Andrea Arcangeli 
Cc: Anshuman Khandual 
Cc: Cannon Matthews 
Cc: Catalin Marinas 
Cc: Chinwen Chang 
Cc: David Rientjes 
Cc: "Dr . David Alan Gilbert" 
Cc: Huang Ying 
Cc: Ingo Molnar 
Cc: Jann Horn 
Cc: Jerome Glisse 
Cc: Kirill A. Shutemov 
Cc: Lokesh Gidra 
Cc: "Matthew Wilcox (Oracle)" 
Cc: Michael Ellerman 
Cc: "Michal Koutn" 
Cc: Michel Lespinasse 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Cc: Mina Almasry 
Cc: Nicholas Piggin 
Cc: Oliver Upton 
Cc: Shaohua Li 
Cc: Shawn Anastasio 
Cc: Steven Price 
Cc: Steven Rostedt 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_alloc: combine __alloc_pages and __alloc_pages_nodemask

2021-04-30T18:20:42+00:00

There are only two callers of __alloc_pages() so prune the thicket of
alloc_page variants by combining the two functions together.  Current
callers of __alloc_pages() simply add an extra 'NULL' parameter and
current callers of __alloc_pages_nodemask() call __alloc_pages() instead.

Link: https://lkml.kernel.org/r/20210225150642.2582252-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Cc: Mike Rapoport 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation: Add leading slash to some paths

2021-03-31T19:49:19+00:00

Change multiple sys/xyz to /sys/xyz

Signed-off-by: Mark O'Donovan 
Link: https://lore.kernel.org/r/20210328152837.73347-1-shiftee@posteo.net
Signed-off-by: Jonathan Corbet

Documentation: sysfs/memory: clarify some memory block device properties

2021-02-26T17:41:00+00:00

In commit 53cdc1cb29e8 ("drivers/base/memory.c: indicate all memory blocks
as removable") we changed the output of the "removable" property of memory
devices to return "1" if and only if the kernel supports memory offlining.

Let's update documentation, stating that the interface is legacy.  Also
update documentation of the "state" property and "valid_zones" properties.

Link: https://lkml.kernel.org/r/20210201181347.13262-3-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Reviewed-by: Oscar Salvador 
Cc: Dave Hansen 
Cc: Jonathan Corbet 
Cc: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: Jonathan Cameron 
Cc: Ilya Dryomov 
Cc: Mauro Carvalho Chehab 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/base/memory: don't store phys_device in memory blocks

2021-02-26T17:41:00+00:00

No need to store the value for each and every memory block, as we can
easily query the value at runtime.  Reshuffle the members to optimize the
memory layout.  Also, let's clarify what the interface once was used for
and why it's legacy nowadays.

"phys_device" was used on s390x in older versions of lsmem[2]/chmem[3],
back when they were still part of s390x-tools.  They were later replaced
by the variants in linux-utils.  For example, RHEL6 and RHEL7 contain
lsmem/chmem from s390-utils.  RHEL8 switched to versions from util-linux
on s390x [4].

"phys_device" was added with sysfs support for memory hotplug in commit
3947be1969a9 ("[PATCH] memory hotplug: sysfs and add/remove functions") in
2005.  It always returned 0.

s390x started returning something != 0 on some setups (if sclp.rzm is set
by HW) in 2010 via commit 57b552ba0b2f ("memory hotplug/s390: set
phys_device").

For s390x, it allowed for identifying which memory block devices belong to
the same storage increment (RZM).  Only if all memory block devices
comprising a single storage increment were offline, the memory could
actually be removed in the hypervisor.

Since commit e5d709bb5fb7 ("s390/memory hotplug: provide
memory_block_size_bytes() function") in 2013 a memory block device spans
at least one storage increment - which is why the interface isn't really
helpful/used anymore (except by old lsmem/chmem tools).

There were once RFC patches to make use of "phys_device" in ACPI context;
however, the underlying problem could be solved using different interfaces
[1].

[1] https://patchwork.kernel.org/patch/2163871/
[2] https://github.com/ibm-s390-tools/s390-tools/blob/v2.1.0/zconf/lsmem
[3] https://github.com/ibm-s390-tools/s390-tools/blob/v2.1.0/zconf/chmem
[4] https://bugzilla.redhat.com/show_bug.cgi?id=1504134

Link: https://lkml.kernel.org/r/20210201181347.13262-2-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: Michal Hocko 
Reviewed-by: Oscar Salvador 
Cc: Dave Hansen 
Cc: Greg Kroah-Hartman 
Cc: Gerald Schaefer 
Cc: Jonathan Corbet 
Cc: "Rafael J. Wysocki" 
Cc: Mauro Carvalho Chehab 
Cc: Ilya Dryomov 
Cc: Vaibhav Jain 
Cc: Tom Rix 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

docs/mm: concepts.rst: Correct the threshold to low watermark

2020-12-31T22:47:34+00:00

It should be "low watermark" where we wake up kswapd daemon.

Signed-off-by: Liao Pingfang 
Link: https://lore.kernel.org/r/1609053319-3112-1-git-send-email-winndows@163.com
Signed-off-by: Jonathan Corbet

Merge branch 'akpm' (patches from Andrew)

2020-12-15T20:53:37+00:00

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton : (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

docs/vm: remove unused 3 items explanation for /proc/vmstat

2020-12-15T20:13:42+00:00

Commit 5647bc293ab1 ("mm: compaction: Move migration fail/success
stats to migrate.c"), removed 3 items in /proc/vmstat. but the docs
still has their explanation. let's remove them.

"compact_blocks_moved",
"compact_pages_moved",
"compact_pagemigrate_failed",

Link: https://lkml.kernel.org/r/1605520282-51993-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi 
Reviewed-by: Zi Yan 
Cc: Jonathan Corbet 
Cc: Yang Shi 
Cc: "Kirill A. Shutemov" 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation: fix multiple typos found in the admin-guide subdirectory

2020-12-08T17:27:56+00:00

Fix thirty five typos in dm-integrity.rst, dm-raid.rst, dm-zoned.rst,
verity.rst, writecache.rst, tsx_async_abort.rst, md.rst, bttv.rst,
dvb_references.rst, frontend-cardlist.rst, gspca-cardlist.rst, ipu3.rst,
remote-controller.rst, mm/index.rst, numaperf.rst, userfaultfd.rst,
module-signing.rst, imx-ddr.rst, intel-speed-select.rst,
intel_pstate.rst, ramoops.rst, abi.rst, kernel.rst, vm.rst

Signed-off-by: Andrew Klychkov 
Link: https://lore.kernel.org/r/20201204072848.GA49895@spblnx124.lan
Signed-off-by: Jonathan Corbet