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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-19 19:21:03 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-19 19:21:03 +0300
commit61307b7be41a1f1039d1d1368810a1d92cb97b44 (patch)
tree639e233e177f8618cd5f86daeb7efc6b095890f0 /Documentation/admin-guide
parent0450d2083be6bdcd18c9535ac50c55266499b2df (diff)
parent76edc534cc289308130272a2ac28694fc9b72a03 (diff)
downloadlinux-61307b7be41a1f1039d1d1368810a1d92cb97b44.tar.xz
Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/blockdev/zram.rst5
-rw-r--r--Documentation/admin-guide/cgroup-v1/memory.rst8
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt6
-rw-r--r--Documentation/admin-guide/mm/damon/usage.rst32
-rw-r--r--Documentation/admin-guide/mm/hugetlbpage.rst7
-rw-r--r--Documentation/admin-guide/mm/transhuge.rst35
-rw-r--r--Documentation/admin-guide/mm/zswap.rst29
-rw-r--r--Documentation/admin-guide/sysctl/vm.rst16
8 files changed, 86 insertions, 52 deletions
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst
index ee2b0030d416..091e8bb38887 100644
--- a/Documentation/admin-guide/blockdev/zram.rst
+++ b/Documentation/admin-guide/blockdev/zram.rst
@@ -466,6 +466,11 @@ of equal or greater size:::
#recompress idle pages larger than 2000 bytes
echo "type=idle threshold=2000" > /sys/block/zramX/recompress
+It is also possible to limit the number of pages zram re-compression will
+attempt to recompress:::
+
+ echo "type=huge_idle max_pages=42" > /sys/block/zramX/recompress
+
Recompression of idle pages requires memory tracking.
During re-compression for every page, that matches re-compression criteria,
diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst
index ca7d9402f6be..9cde26d33843 100644
--- a/Documentation/admin-guide/cgroup-v1/memory.rst
+++ b/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -300,14 +300,14 @@ When oom event notifier is registered, event will be delivered.
Lock order is as follows::
- Page lock (PG_locked bit of page->flags)
+ folio_lock
mm->page_table_lock or split pte_lock
folio_memcg_lock (memcg->move_lock)
mapping->i_pages lock
lruvec->lru_lock.
Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by
-lruvec->lru_lock; PG_lru bit of page->flags is cleared before
+lruvec->lru_lock; the folio LRU flag is cleared before
isolating a page from its LRU under lruvec->lru_lock.
.. _cgroup-v1-memory-kernel-extension:
@@ -802,8 +802,8 @@ a page or a swap can be moved only when it is charged to the task's current
| | anonymous pages, file pages (and swaps) in the range mmapped by the task |
| | will be moved even if the task hasn't done page fault, i.e. they might |
| | not be the task's "RSS", but other task's "RSS" that maps the same file. |
-| | And mapcount of the page is ignored (the page can be moved even if |
-| | page_mapcount(page) > 1). You must enable Swap Extension (see 2.4) to |
+| | The mapcount of the page is ignored (the page can be moved independent |
+| | of the mapcount). You must enable Swap Extension (see 2.4) to |
| | enable move of swap charges. |
+---+--------------------------------------------------------------------------+
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 45d95614ec44..90f79a285427 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2151,6 +2151,12 @@
Format: 0 | 1
Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
+ init_mlocked_on_free= [MM] Fill freed userspace memory with zeroes if
+ it was mlock'ed and not explicitly munlock'ed
+ afterwards.
+ Format: 0 | 1
+ Default set by CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON
+
init_pkru= [X86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 6fce035fdbf5..e58ceb89ea2a 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -153,7 +153,7 @@ Users can write below commands for the kdamond to the ``state`` file.
- ``clear_schemes_tried_regions``: Clear the DAMON-based operating scheme
action tried regions directory for each DAMON-based operation scheme of the
kdamond.
-- ``update_schemes_effective_bytes``: Update the contents of
+- ``update_schemes_effective_quotas``: Update the contents of
``effective_bytes`` files for each DAMON-based operation scheme of the
kdamond. For more details, refer to :ref:`quotas directory <sysfs_quotas>`.
@@ -342,7 +342,7 @@ Based on the user-specified :ref:`goal <sysfs_schemes_quota_goals>`, the
effective size quota is further adjusted. Reading ``effective_bytes`` returns
the current effective size quota. The file is not updated in real time, so
users should ask DAMON sysfs interface to update the content of the file for
-the stats by writing a special keyword, ``update_schemes_effective_bytes`` to
+the stats by writing a special keyword, ``update_schemes_effective_quotas`` to
the relevant ``kdamonds/<N>/state`` file.
Under ``weights`` directory, three files (``sz_permil``,
@@ -410,19 +410,19 @@ in the numeric order.
Each filter directory contains six files, namely ``type``, ``matcing``,
``memcg_path``, ``addr_start``, ``addr_end``, and ``target_idx``. To ``type``
-file, you can write one of four special keywords: ``anon`` for anonymous pages,
-``memcg`` for specific memory cgroup, ``addr`` for specific address range (an
-open-ended interval), or ``target`` for specific DAMON monitoring target
-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. In case of the address range
-filtering, you can specify the start and end address of the range to
-``addr_start`` and ``addr_end`` files, respectively. For the DAMON monitoring
-target filtering, you can specify the index of the target between the list of
-the DAMON context's monitoring targets list to ``target_idx`` 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.
+file, you can write one of five special keywords: ``anon`` for anonymous pages,
+``memcg`` for specific memory cgroup, ``young`` for young pages, ``addr`` for
+specific address range (an open-ended interval), or ``target`` for specific
+DAMON monitoring target 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. In case of the
+address range filtering, you can specify the start and end address of the range
+to ``addr_start`` and ``addr_end`` files, respectively. For the DAMON
+monitoring target filtering, you can specify the index of the target between
+the list of the DAMON context's monitoring targets list to ``target_idx`` 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``.::
@@ -434,7 +434,7 @@ pages of all memory cgroups except ``/having_care_already``.::
# # 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
+ echo Y > 1/matching
Note that ``anon`` and ``memcg`` filters are currently supported only when
``paddr`` :ref:`implementation <sysfs_context>` is being used.
diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst
index e4d4b4a8dc97..f34a0d798d5b 100644
--- a/Documentation/admin-guide/mm/hugetlbpage.rst
+++ b/Documentation/admin-guide/mm/hugetlbpage.rst
@@ -376,6 +376,13 @@ Note that the number of overcommit and reserve pages remain global quantities,
as we don't know until fault time, when the faulting task's mempolicy is
applied, from which node the huge page allocation will be attempted.
+The hugetlb may be migrated between the per-node hugepages pool in the following
+scenarios: memory offline, memory failure, longterm pinning, syscalls(mbind,
+migrate_pages and move_pages), alloc_contig_range() and alloc_contig_pages().
+Now only memory offline, memory failure and syscalls allow fallbacking to allocate
+a new hugetlb on a different node if the current node is unable to allocate during
+hugetlb migration, that means these 3 cases can break the per-node hugepages pool.
+
.. _using_huge_pages:
Using Huge Pages
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index 04eb45a2f940..076443cc10a6 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -278,7 +278,8 @@ collapsed, resulting fewer pages being collapsed into
THPs, and lower memory access performance.
``max_ptes_shared`` specifies how many pages can be shared across multiple
-processes. Exceeding the number would block the collapse::
+processes. khugepaged might treat pages of THPs as shared if any page of
+that THP is shared. Exceeding the number would block the collapse::
/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_shared
@@ -369,7 +370,7 @@ monitor how successfully the system is providing huge pages for use.
thp_fault_alloc
is incremented every time a huge page is successfully
- allocated to handle a page fault.
+ allocated and charged to handle a page fault.
thp_collapse_alloc
is incremented by khugepaged when it has found
@@ -377,7 +378,7 @@ thp_collapse_alloc
successfully allocated a new huge page to store the data.
thp_fault_fallback
- is incremented if a page fault fails to allocate
+ is incremented if a page fault fails to allocate or charge
a huge page and instead falls back to using small pages.
thp_fault_fallback_charge
@@ -447,6 +448,34 @@ thp_swpout_fallback
Usually because failed to allocate some continuous swap space
for the huge page.
+In /sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/stats, There are
+also individual counters for each huge page size, which can be utilized to
+monitor the system's effectiveness in providing huge pages for usage. Each
+counter has its own corresponding file.
+
+anon_fault_alloc
+ is incremented every time a huge page is successfully
+ allocated and charged to handle a page fault.
+
+anon_fault_fallback
+ is incremented if a page fault fails to allocate or charge
+ a huge page and instead falls back to using huge pages with
+ lower orders or small pages.
+
+anon_fault_fallback_charge
+ is incremented if a page fault fails to charge a huge page and
+ instead falls back to using huge pages with lower orders or
+ small pages even though the allocation was successful.
+
+anon_swpout
+ is incremented every time a huge page is swapped out in one
+ piece without splitting.
+
+anon_swpout_fallback
+ is incremented if a huge page has to be split before swapout.
+ Usually because failed to allocate some continuous swap space
+ for the huge page.
+
As the system ages, allocating huge pages may be expensive as the
system uses memory compaction to copy data around memory to free a
huge page for use. There are some counters in ``/proc/vmstat`` to help
diff --git a/Documentation/admin-guide/mm/zswap.rst b/Documentation/admin-guide/mm/zswap.rst
index 13632671adae..3598dcd7dbe7 100644
--- a/Documentation/admin-guide/mm/zswap.rst
+++ b/Documentation/admin-guide/mm/zswap.rst
@@ -111,35 +111,6 @@ checked if it is a same-value filled page before compressing it. If true, the
compressed length of the page is set to zero and the pattern or same-filled
value is stored.
-Same-value filled pages identification feature is enabled by default and can be
-disabled at boot time by setting the ``same_filled_pages_enabled`` attribute
-to 0, e.g. ``zswap.same_filled_pages_enabled=0``. It can also be enabled and
-disabled at runtime using the sysfs ``same_filled_pages_enabled``
-attribute, e.g.::
-
- echo 1 > /sys/module/zswap/parameters/same_filled_pages_enabled
-
-When zswap same-filled page identification is disabled at runtime, it will stop
-checking for the same-value filled pages during store operation.
-In other words, every page will be then considered non-same-value filled.
-However, the existing pages which are marked as same-value filled pages remain
-stored unchanged in zswap until they are either loaded or invalidated.
-
-In some circumstances it might be advantageous to make use of just the zswap
-ability to efficiently store same-filled pages without enabling the whole
-compressed page storage.
-In this case the handling of non-same-value pages by zswap (enabled by default)
-can be disabled by setting the ``non_same_filled_pages_enabled`` attribute
-to 0, e.g. ``zswap.non_same_filled_pages_enabled=0``.
-It can also be enabled and disabled at runtime using the sysfs
-``non_same_filled_pages_enabled`` attribute, e.g.::
-
- echo 1 > /sys/module/zswap/parameters/non_same_filled_pages_enabled
-
-Disabling both ``zswap.same_filled_pages_enabled`` and
-``zswap.non_same_filled_pages_enabled`` effectively disables accepting any new
-pages by zswap.
-
To prevent zswap from shrinking pool when zswap is full and there's a high
pressure on swap (this will result in flipping pages in and out zswap pool
without any real benefit but with a performance drop for the system), a
diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index c59889de122b..e86c968a7a0e 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -43,6 +43,7 @@ Currently, these files are in /proc/sys/vm:
- legacy_va_layout
- lowmem_reserve_ratio
- max_map_count
+- mem_profiling (only if CONFIG_MEM_ALLOC_PROFILING=y)
- memory_failure_early_kill
- memory_failure_recovery
- min_free_kbytes
@@ -425,6 +426,21 @@ e.g., up to one or two maps per allocation.
The default value is 65530.
+mem_profiling
+==============
+
+Enable memory profiling (when CONFIG_MEM_ALLOC_PROFILING=y)
+
+1: Enable memory profiling.
+
+0: Disable memory profiling.
+
+Enabling memory profiling introduces a small performance overhead for all
+memory allocations.
+
+The default value depends on CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT.
+
+
memory_failure_early_kill:
==========================