Pull more MM updates from Andrew Morton: - "zram: support algorithm-specific parameters" from Sergey Senozhatsky adds infrastructure for passing algorithm-specific parameters into zram. A single parameter `winbits' is implemented at this time. - "memcg: nmi-safe kmem charging" from Shakeel Butt makes memcg charging nmi-safe, which is required by BFP, which can operate in NMI context. - "Some random fixes and cleanup to shmem" from Kemeng Shi implements small fixes and cleanups in the shmem code. - "Skip mm selftests instead when kernel features are not present" from Zi Yan fixes some issues in the MM selftest code. - "mm/damon: build-enable essential DAMON components by default" from SeongJae Park reworks DAMON Kconfig to make it easier to enable CONFIG_DAMON. - "sched/numa: add statistics of numa balance task migration" from Libo Chen adds more info into sysfs and procfs files to improve visibility into the NUMA balancer's task migration activity. - "selftests/mm: cow and gup_longterm cleanups" from Mark Brown provides various updates to some of the MM selftests to make them play better with the overall containing framework. * tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (43 commits) mm/khugepaged: clean up refcount check using folio_expected_ref_count() selftests/mm: fix test result reporting in gup_longterm selftests/mm: report unique test names for each cow test selftests/mm: add helper for logging test start and results selftests/mm: use standard ksft_finished() in cow and gup_longterm selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled sched/numa: add statistics of numa balance task sched/numa: fix task swap by skipping kernel threads tools/testing: check correct variable in open_procmap() tools/testing/vma: add missing function stub mm/gup: update comment explaining why gup_fast() disables IRQs selftests/mm: two fixes for the pfnmap test mm/khugepaged: fix race with folio split/free using temporary reference mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order mmu_notifiers: remove leftover stub macros selftests/mm: deduplicate test names in madv_populate kcov: rust: add flags for KCOV with Rust mm: rust: make CONFIG_MMU ifdefs more narrow mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables() mm/damon/Kconfig: enable CONFIG_DAMON by default ...
Problem: On large page size configurations (16KiB, 64KiB), the CMA
alignment requirement (CMA_MIN_ALIGNMENT_BYTES) increases considerably,
and this causes the CMA reservations to be larger than necessary. This
means that system will have less available MIGRATE_UNMOVABLE and
MIGRATE_RECLAIMABLE page blocks since MIGRATE_CMA can't fallback to them.
The CMA_MIN_ALIGNMENT_BYTES increases because it depends on MAX_PAGE_ORDER
which depends on ARCH_FORCE_MAX_ORDER. The value of ARCH_FORCE_MAX_ORDER
increases on 16k and 64k kernels.
For example, in ARM, the CMA alignment requirement when:
- CONFIG_ARCH_FORCE_MAX_ORDER default value is used
- CONFIG_TRANSPARENT_HUGEPAGE is set:
PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES
-----------------------------------------------------------------------
4KiB | 10 | 9 | 4KiB * (2 ^ 9) = 2MiB
16Kib | 11 | 11 | 16KiB * (2 ^ 11) = 32MiB
64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB
There are some extreme cases for the CMA alignment requirement when:
- CONFIG_ARCH_FORCE_MAX_ORDER maximum value is set
- CONFIG_TRANSPARENT_HUGEPAGE is NOT set:
- CONFIG_HUGETLB_PAGE is NOT set
PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES
------------------------------------------------------------------------
4KiB | 15 | 15 | 4KiB * (2 ^ 15) = 128MiB
16Kib | 13 | 13 | 16KiB * (2 ^ 13) = 128MiB
64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB
This affects the CMA reservations for the drivers. If a driver in a
4KiB kernel needs 4MiB of CMA memory, in a 16KiB kernel, the minimal
reservation has to be 32MiB due to the alignment requirements:
reserved-memory {
...
cma_test_reserve: cma_test_reserve {
compatible = "shared-dma-pool";
size = <0x0 0x400000>; /* 4 MiB */
...
};
};
reserved-memory {
...
cma_test_reserve: cma_test_reserve {
compatible = "shared-dma-pool";
size = <0x0 0x2000000>; /* 32 MiB */
...
};
};
Solution: Add a new config CONFIG_PAGE_BLOCK_ORDER that allows to set the
page block order in all the architectures. The maximum page block order
will be given by ARCH_FORCE_MAX_ORDER.
By default, CONFIG_PAGE_BLOCK_ORDER will have the same value that
ARCH_FORCE_MAX_ORDER. This will make sure that current kernel
configurations won't be affected by this change. It is a opt-in change.
This patch will allow to have the same CMA alignment requirements for
large page sizes (16KiB, 64KiB) as that in 4kb kernels by setting a lower
pageblock_order.
Tests:
- Verified that HugeTLB pages work when pageblock_order is 1, 7, 10 on
4k and 16k kernels.
- Verified that Transparent Huge Pages work when pageblock_order is 1,
7, 10 on 4k and 16k kernels.
- Verified that dma-buf heaps allocations work when pageblock_order is
1, 7, 10 on 4k and 16k kernels.
Benchmarks:
The benchmarks compare 16kb kernels with pageblock_order 10 and 7. The
reason for the pageblock_order 7 is because this value makes the min CMA
alignment requirement the same as that in 4kb kernels (2MB).
- Perform 100K dma-buf heaps (/dev/dma_heap/system) allocations of
SZ_8M, SZ_4M, SZ_2M, SZ_1M, SZ_64, SZ_8, SZ_4. Use simpleperf
(https://developer.android.com/ndk/guides/simpleperf) to measure the #
of instructions and page-faults on 16k kernels. The benchmark was
executed 10 times. The averages are below:
# instructions | #page-faults
order 10 | order 7 | order 10 | order 7
--------------------------------------------------------
13,891,765,770 | 11,425,777,314 | 220 | 217
14,456,293,487 | 12,660,819,302 | 224 | 219
13,924,261,018 | 13,243,970,736 | 217 | 221
13,910,886,504 | 13,845,519,630 | 217 | 221
14,388,071,190 | 13,498,583,098 | 223 | 224
13,656,442,167 | 12,915,831,681 | 216 | 218
13,300,268,343 | 12,930,484,776 | 222 | 218
13,625,470,223 | 14,234,092,777 | 219 | 218
13,508,964,965 | 13,432,689,094 | 225 | 219
13,368,950,667 | 13,683,587,37 | 219 | 225
-------------------------------------------------------------------
13,803,137,433 | 13,131,974,268 | 220 | 220 Averages
There were 4.85% #instructions when order was 7, in comparison with order
10.
13,803,137,433 - 13,131,974,268 = -671,163,166 (-4.86%)
The number of page faults in order 7 and 10 were the same.
These results didn't show any significant regression when the
pageblock_order is set to 7 on 16kb kernels.
- Run speedometer 3.1 (https://browserbench.org/Speedometer3.1/) 5 times
on the 16k kernels with pageblock_order 7 and 10.
order 10 | order 7 | order 7 - order 10 | (order 7 - order 10) %
-------------------------------------------------------------------
15.8 | 16.4 | 0.6 | 3.80%
16.4 | 16.2 | -0.2 | -1.22%
16.6 | 16.3 | -0.3 | -1.81%
16.8 | 16.3 | -0.5 | -2.98%
16.6 | 16.8 | 0.2 | 1.20%
-------------------------------------------------------------------
16.44 16.4 -0.04 -0.24% Averages
The results didn't show any significant regression when the
pageblock_order is set to 7 on 16kb kernels.
Link: https://lkml.kernel.org/r/20250521215807.1860663-1-jyescas@google.com
Signed-off-by: Juan Yescas <jyescas@google.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ...
Implement for_each_valid_pfn() based on two helper functions. The first_valid_pfn() function largely mirrors pfn_valid(), calling into a pfn_section_first_valid() helper which is trivial for the !VMEMMAP case, and in the VMEMMAP case will skip to the next subsection as needed. Since next_valid_pfn() knows that its argument *is* a valid PFN, it doesn't need to do any checking at all while iterating over the low bits within a (sub)section mask; the whole (sub)section is either present or not. Note that the VMEMMAP version of pfn_section_first_valid() may return a value *higher* than end_pfn when skipping to the next subsection, and first_valid_pfn() happily returns that higher value. This is fine. [dwmw2@infradead.org: fix next_valid_pfn() for sparsemem] Link: https://lkml.kernel.org/r/c15100fcf6781a60b852c4dbb43bdc98a678fcf0.camel@infradead.org Link: https://lkml.kernel.org/r/20250423133821.789413-4-dwmw2@infradead.org Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Ruihan Li <lrh2000@pku.edu.cn> Cc: Will Deacon <will@kernel.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: Introduce for_each_valid_pfn()", v4.
There are cases where a naïve loop over a PFN range, calling pfn_valid()
on each one, is horribly inefficient. Ruihan Li reported the case where
memmap_init() iterates all the way from zero to a potentially large value
of ARCH_PFN_OFFSET, and we at Amazon found the reserve_bootmem_region()
one as it affects hypervisor live update. Others are more cosmetic.
By introducing a for_each_valid_pfn() helper it can optimise away a lot of
pointless calls to pfn_valid(), skipping immediately to the next valid PFN
and also skipping *all* checks within a valid (sub)region according to the
granularity of the memory model in use.
This patch (of 7)
Especially since commit 9092d4f7a1f8 ("memblock: update initialization of
reserved pages"), the reserve_bootmem_region() function can spend a
significant amount of time iterating over every 4KiB PFN in a range,
calling pfn_valid() on each one, and ultimately doing absolutely nothing.
On a platform used for virtualization, with large NOMAP regions that
eventually get used for guest RAM, this leads to a significant increase in
steal time experienced during kexec for a live update.
Introduce for_each_valid_pfn() and use it from reserve_bootmem_region().
This implementation is precisely the same naïve loop that the functio
used to have, but subsequent commits will provide optimised versions for
FLATMEM and SPARSEMEM, and this version will remain for those
architectures which provide their own pfn_valid() implementation,
until/unless they also provide a matching for_each_valid_pfn().
Link: https://lkml.kernel.org/r/20250423133821.789413-1-dwmw2@infradead.org
Link: https://lkml.kernel.org/r/20250423133821.789413-2-dwmw2@infradead.org
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Ruihan Li <lrh2000@pku.edu.cn>
Cc: Will Deacon <will@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The stat is always 0 now, so remove it and hardwire the user visible output to 0. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250505081138.3435992-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Vlastimil points out that commit a211c6550efc ("mm: page_alloc:
defrag_mode kswapd/kcompactd watermarks") switched kswapd from
zone_watermark_ok_safe() to the standard, percpu-cached version of reading
free pages, thus dropping the watermark safety precautions for systems
with high CPU counts (e.g. >212 cpus on 64G). Restore them.
Since zone_watermark_ok_safe() is no longer the right interface, and this
was the last caller of the function anyway, open-code the
zone_page_state_snapshot() conditional and delete the function.
Link: https://lkml.kernel.org/r/20250416135142.778933-2-hannes@cmpxchg.org
Fixes: a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When the last page in the zone is accepted, __accept_page() calls
static_branch_dec(). This function takes cpu_hotplug_lock, which can lead
to a deadlock if the allocation occurs during CPU bringup path as
_cpu_up() also takes the lock.
To prevent this deadlock, defer static_branch_dec() to a workqueue.
Call static_branch_dec() only when the workqueue is not yet initialized.
Workqueues are initialized before CPU bring up, so this will not conflict
with the first scenario.
Link: https://lkml.kernel.org/r/20250329171030.3942298-1-kirill.shutemov@linux.intel.com
Fixes: 55ad43e8ba0f ("mm: add a helper to accept page")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Srikanth Aithal <sraithal@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
Patch series "Adding Proactive Memory Reclaim Statistics". These two patches are related to proactive memory reclaim. Patch 1 Split proactive reclaim statistics from direct reclaim counters and introduces new counters: pgsteal_proactive, pgdemote_proactive, and pgscan_proactive. Patch 2 Adds pswpin and pswpout items to the cgroup-v2 documentation. This patch (of 2): In proactive memory reclaim scenarios, it is necessary to accurately track proactive reclaim statistics to dynamically adjust the frequency and amount of memory being reclaimed proactively. Currently, proactive reclaim is included in direct reclaim statistics, which can make these direct reclaim statistics misleading. Therefore, separate proactive reclaim memory from the direct reclaim counters by introducing new counters: pgsteal_proactive, pgdemote_proactive, and pgscan_proactive, to avoid confusion with direct reclaim. Link: https://lkml.kernel.org/r/20250318075833.90615-1-jiahao.kernel@gmail.com Link: https://lkml.kernel.org/r/20250318075833.90615-2-jiahao.kernel@gmail.com Signed-off-by: Hao Jia <jiahao1@lixiang.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>