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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 04:09:35 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 04:09:35 +0300
commit3822a7c40997dc86b1458766a3f146d62393f084 (patch)
tree4473720ecbfaabeedfe58484425be77d0f89f736 /Documentation/admin-guide
parente4bc15889506723d7b93c053ad4a75cd58248d74 (diff)
parentf9366f4c2a29d14f5992b195e268240c2deb116e (diff)
downloadlinux-3822a7c40997dc86b1458766a3f146d62393f084.tar.xz
Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/cgroup-v1/memory.rst13
-rw-r--r--Documentation/admin-guide/mm/damon/reclaim.rst9
-rw-r--r--Documentation/admin-guide/mm/damon/usage.rst105
-rw-r--r--Documentation/admin-guide/mm/hugetlbpage.rst6
-rw-r--r--Documentation/admin-guide/mm/idle_page_tracking.rst2
-rw-r--r--Documentation/admin-guide/mm/numaperf.rst8
-rw-r--r--Documentation/admin-guide/mm/pagemap.rst4
7 files changed, 115 insertions, 32 deletions
diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst
index 27d89495ac88..47d1d7d932a8 100644
--- a/Documentation/admin-guide/cgroup-v1/memory.rst
+++ b/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -87,6 +87,8 @@ Brief summary of control files.
memory.swappiness set/show swappiness parameter of vmscan
(See sysctl's vm.swappiness)
memory.move_charge_at_immigrate set/show controls of moving charges
+ This knob is deprecated and shouldn't be
+ used.
memory.oom_control set/show oom controls.
memory.numa_stat show the number of memory usage per numa
node
@@ -727,8 +729,15 @@ If we want to change this to 1G, we can at any time use::
.. _cgroup-v1-memory-move-charges:
-8. Move charges at task migration
-=================================
+8. Move charges at task migration (DEPRECATED!)
+===============================================
+
+THIS IS DEPRECATED!
+
+It's expensive and unreliable! It's better practice to launch workload
+tasks directly from inside their target cgroup. Use dedicated workload
+cgroups to allow fine-grained policy adjustments without having to
+move physical pages between control domains.
Users can move charges associated with a task along with task migration, that
is, uncharge task's pages from the old cgroup and charge them to the new cgroup.
diff --git a/Documentation/admin-guide/mm/damon/reclaim.rst b/Documentation/admin-guide/mm/damon/reclaim.rst
index d2ccd9c21b9a..343e25b252f4 100644
--- a/Documentation/admin-guide/mm/damon/reclaim.rst
+++ b/Documentation/admin-guide/mm/damon/reclaim.rst
@@ -205,6 +205,15 @@ The end physical address of memory region that DAMON_RECLAIM will do work
against. That is, DAMON_RECLAIM will find cold memory regions in this region
and reclaims. By default, biggest System RAM is used as the region.
+skip_anon
+---------
+
+Skip anonymous pages reclamation.
+
+If this parameter is set as ``Y``, DAMON_RECLAIM does not reclaim anonymous
+pages. By default, ``N``.
+
+
kdamond_pid
-----------
diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 1a5b6b71efa1..9b823fec974d 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -25,10 +25,12 @@ DAMON provides below interfaces for different users.
interface provides only simple :ref:`statistics <damos_stats>` for the
monitoring results. For detailed monitoring results, DAMON provides a
:ref:`tracepoint <tracepoint>`.
-- *debugfs interface.*
+- *debugfs interface. (DEPRECATED!)*
:ref:`This <debugfs_interface>` is almost identical to :ref:`sysfs interface
- <sysfs_interface>`. This will be removed after next LTS kernel is released,
- so users should move to the :ref:`sysfs interface <sysfs_interface>`.
+ <sysfs_interface>`. This is deprecated, so users should move to the
+ :ref:`sysfs interface <sysfs_interface>`. If you depend on this and cannot
+ move, please report your usecase to damon@lists.linux.dev and
+ linux-mm@kvack.org.
- *Kernel Space Programming Interface.*
:doc:`This </mm/damon/api>` is for kernel space programmers. Using this,
users can utilize every feature of DAMON most flexibly and efficiently by
@@ -87,6 +89,8 @@ comma (","). ::
│ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms
│ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil
│ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low
+ │ │ │ │ │ │ │ filters/nr_filters
+ │ │ │ │ │ │ │ │ 0/type,matching,memcg_id
│ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds
│ │ │ │ │ │ │ tried_regions/
│ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age
@@ -151,6 +155,8 @@ number (``N``) to the file creates the number of child directories named as
moment, only one context per kdamond is supported, so only ``0`` or ``1`` can
be written to the file.
+.. _sysfs_contexts:
+
contexts/<N>/
-------------
@@ -268,21 +274,32 @@ schemes/<N>/
------------
In each scheme directory, five directories (``access_pattern``, ``quotas``,
-``watermarks``, ``stats``, and ``tried_regions``) and one file (``action``)
-exist.
+``watermarks``, ``filters``, ``stats``, and ``tried_regions``) and one file
+(``action``) exist.
The ``action`` file is for setting and getting what action you want to apply to
memory regions having specific access pattern of the interest. The keywords
that can be written to and read from the file and their meaning are as below.
- - ``willneed``: Call ``madvise()`` for the region with ``MADV_WILLNEED``
- - ``cold``: Call ``madvise()`` for the region with ``MADV_COLD``
- - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT``
- - ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``
- - ``nohugepage``: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``
+Note that support of each action depends on the running DAMON operations set
+`implementation <sysfs_contexts>`.
+
+ - ``willneed``: Call ``madvise()`` for the region with ``MADV_WILLNEED``.
+ Supported by ``vaddr`` and ``fvaddr`` operations set.
+ - ``cold``: Call ``madvise()`` for the region with ``MADV_COLD``.
+ Supported by ``vaddr`` and ``fvaddr`` operations set.
+ - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT``.
+ Supported by ``vaddr``, ``fvaddr`` and ``paddr`` operations set.
+ - ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``.
+ Supported by ``vaddr`` and ``fvaddr`` operations set.
+ - ``nohugepage``: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``.
+ Supported by ``vaddr`` and ``fvaddr`` operations set.
- ``lru_prio``: Prioritize the region on its LRU lists.
+ Supported by ``paddr`` operations set.
- ``lru_deprio``: Deprioritize the region on its LRU lists.
- - ``stat``: Do nothing but count the statistics
+ Supported by ``paddr`` operations set.
+ - ``stat``: Do nothing but count the statistics.
+ Supported by all operations sets.
schemes/<N>/access_pattern/
---------------------------
@@ -347,6 +364,46 @@ as below.
The ``interval`` should written in microseconds unit.
+schemes/<N>/filters/
+--------------------
+
+Users could know something more than the kernel for specific types of memory.
+In the case, users could do their own management for the memory and hence
+doesn't want DAMOS bothers that. Users could limit DAMOS by setting the access
+pattern of the scheme and/or the monitoring regions for the purpose, but that
+can be inefficient in some cases. In such cases, users could set non-access
+pattern driven filters using files in this directory.
+
+In the beginning, this directory has only one file, ``nr_filters``. Writing a
+number (``N``) to the file creates the number of child directories named ``0``
+to ``N-1``. Each directory represents each filter. The filters are evaluated
+in the numeric order.
+
+Each filter directory contains three files, namely ``type``, ``matcing``, and
+``memcg_path``. You can write one of two special keywords, ``anon`` for
+anonymous pages, or ``memcg`` for specific memory cgroup filtering. In case of
+the memory cgroup filtering, you can specify the memory cgroup of the interest
+by writing the path of the memory cgroup from the cgroups mount point to
+``memcg_path`` file. You can write ``Y`` or ``N`` to ``matching`` file to
+filter out pages that does or does not match to the type, respectively. Then,
+the scheme's action will not be applied to the pages that specified to be
+filtered out.
+
+For example, below restricts a DAMOS action to be applied to only non-anonymous
+pages of all memory cgroups except ``/having_care_already``.::
+
+ # echo 2 > nr_filters
+ # # filter out anonymous pages
+ echo anon > 0/type
+ echo Y > 0/matching
+ # # further filter out all cgroups except one at '/having_care_already'
+ echo memcg > 1/type
+ echo /having_care_already > 1/memcg_path
+ echo N > 1/matching
+
+Note that filters are currently supported only when ``paddr``
+`implementation <sysfs_contexts>` is being used.
+
.. _sysfs_schemes_stats:
schemes/<N>/stats/
@@ -432,13 +489,17 @@ the files as above. Above is only for an example.
.. _debugfs_interface:
-debugfs Interface
-=================
+debugfs Interface (DEPRECATED!)
+===============================
.. note::
- DAMON debugfs interface will be removed after next LTS kernel is released, so
- users should move to the :ref:`sysfs interface <sysfs_interface>`.
+ THIS IS DEPRECATED!
+
+ DAMON debugfs interface is deprecated, so users should move to the
+ :ref:`sysfs interface <sysfs_interface>`. If you depend on this and cannot
+ move, please report your usecase to damon@lists.linux.dev and
+ linux-mm@kvack.org.
DAMON exports eight files, ``attrs``, ``target_ids``, ``init_regions``,
``schemes``, ``monitor_on``, ``kdamond_pid``, ``mk_contexts`` and
@@ -574,11 +635,15 @@ The ``<action>`` is a predefined integer for memory management actions, which
DAMON will apply to the regions having the target access pattern. The
supported numbers and their meanings are as below.
- - 0: Call ``madvise()`` for the region with ``MADV_WILLNEED``
- - 1: Call ``madvise()`` for the region with ``MADV_COLD``
- - 2: Call ``madvise()`` for the region with ``MADV_PAGEOUT``
- - 3: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``
- - 4: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``
+ - 0: Call ``madvise()`` for the region with ``MADV_WILLNEED``. Ignored if
+ ``target`` is ``paddr``.
+ - 1: Call ``madvise()`` for the region with ``MADV_COLD``. Ignored if
+ ``target`` is ``paddr``.
+ - 2: Call ``madvise()`` for the region with ``MADV_PAGEOUT``.
+ - 3: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``. Ignored if
+ ``target`` is ``paddr``.
+ - 4: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``. Ignored if
+ ``target`` is ``paddr``.
- 5: Do nothing but count the statistics
Quota
diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst
index bca00cb6f43a..e4d4b4a8dc97 100644
--- a/Documentation/admin-guide/mm/hugetlbpage.rst
+++ b/Documentation/admin-guide/mm/hugetlbpage.rst
@@ -459,13 +459,13 @@ Examples
.. _map_hugetlb:
``map_hugetlb``
- see tools/testing/selftests/vm/map_hugetlb.c
+ see tools/testing/selftests/mm/map_hugetlb.c
``hugepage-shm``
- see tools/testing/selftests/vm/hugepage-shm.c
+ see tools/testing/selftests/mm/hugepage-shm.c
``hugepage-mmap``
- see tools/testing/selftests/vm/hugepage-mmap.c
+ see tools/testing/selftests/mm/hugepage-mmap.c
The `libhugetlbfs`_ library provides a wide range of userspace tools
to help with huge page usability, environment setup, and control.
diff --git a/Documentation/admin-guide/mm/idle_page_tracking.rst b/Documentation/admin-guide/mm/idle_page_tracking.rst
index b5a285bd73fd..16fcf38dac56 100644
--- a/Documentation/admin-guide/mm/idle_page_tracking.rst
+++ b/Documentation/admin-guide/mm/idle_page_tracking.rst
@@ -63,7 +63,7 @@ workload one should:
are not reclaimable, he or she can filter them out using
``/proc/kpageflags``.
-The page-types tool in the tools/vm directory can be used to assist in this.
+The page-types tool in the tools/mm directory can be used to assist in this.
If the tool is run initially with the appropriate option, it will mark all the
queried pages as idle. Subsequent runs of the tool can then show which pages have
their idle flag cleared in the interim.
diff --git a/Documentation/admin-guide/mm/numaperf.rst b/Documentation/admin-guide/mm/numaperf.rst
index 24e63e740420..90a12b6a8bfc 100644
--- a/Documentation/admin-guide/mm/numaperf.rst
+++ b/Documentation/admin-guide/mm/numaperf.rst
@@ -1,4 +1,7 @@
-=============
+=======================
+NUMA Memory Performance
+=======================
+
NUMA Locality
=============
@@ -59,7 +62,6 @@ that are CPUs and hence suitable for generic task scheduling, and
IO initiators such as GPUs and NICs. Unlike access class 0, only
nodes containing CPUs are considered.
-================
NUMA Performance
================
@@ -94,7 +96,6 @@ for the platform.
Access class 1 takes the same form but only includes values for CPU to
memory activity.
-==========
NUMA Cache
==========
@@ -168,7 +169,6 @@ The "size" is the number of bytes provided by this cache level.
The "write_policy" will be 0 for write-back, and non-zero for
write-through caching.
-========
See Also
========
diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst
index 1a22674ab18e..b5f970dc91e7 100644
--- a/Documentation/admin-guide/mm/pagemap.rst
+++ b/Documentation/admin-guide/mm/pagemap.rst
@@ -44,7 +44,7 @@ There are four components to pagemap:
* ``/proc/kpagecount``. This file contains a 64-bit count of the number of
times each page is mapped, indexed by PFN.
-The page-types tool in the tools/vm directory can be used to query the
+The page-types tool in the tools/mm directory can be used to query the
number of times a page is mapped.
* ``/proc/kpageflags``. This file contains a 64-bit set of flags for each
@@ -170,7 +170,7 @@ LRU related page flags
14 - SWAPBACKED
The page is backed by swap/RAM.
-The page-types tool in the tools/vm directory can be used to query the
+The page-types tool in the tools/mm directory can be used to query the
above flags.
Using pagemap to do something useful