Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes)

   Index MAP_PRIVATE file-backed folios by their anonymous page offset
   to resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.

   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.

 - "promote mapped executable folios after first usage for MGLRU"
   (Baolin Wang)

   Make MGLRU's protection of mapped executable file folios more
   reliable. Follow the classical LRU's logic, promoting mapped
   executable file folios after their first usage to give executable
   code a better chance to stay in memory and improve workload
   performance.

 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
   Chen)

   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating
   sc_swappiness() into a single function that checks
   proactive_swappiness regardless of kernel configuration.

 - "mm/vmscan: reduce lru_lock contention via vmstat-derived
   scan-balance cost" (Usama Arif)

   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.

   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over
   60% without impacting scan throughput.

 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)

   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.

 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan)

   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray
   node memory accounting.

 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)

   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.

 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)

   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.

 - "zram: fix zstd error paths and add parameter validation" (Haoqin
   Huang)

   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.

 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia)

   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in
   writeback_store() and read_block_state().

 - "add anon mTHP collapse test cases" (Baolin Wang)

   Extend selftests helper functions to support arbitrary page orders
   and add new test cases and options for mTHP collapse in khugepaged.

 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum)

   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.

 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)

   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.

 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
   Baghdasaryan)

   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.

   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.

 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig)

   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving
   faster swap throughput during kernel builds.

 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas)

   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.

 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao)

   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
   confirming scan.

 - "swap_ops updates" (Christoph Hellwig)

   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead. This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly
   export their own swap_ops.

 - "mm/khugepaged: several cleanups" (Nico Pache)

   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration. Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.

 - "maple_tree: lock checking and clean ups" (Liam Howlett)

   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.

   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to
   GFP_KERNEL | GFP_NOFAIL.

* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
  selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
  memcg: move LRU size accounting on reparenting instead of copying it
  mm/vmscan: fix comment logic in balance_pgdat
  maple_tree: add helper mas_make_walkable()
  maple_tree: avoid extra gap calculation
  maple_tree: fix argument name in header
  maple_tree: change two GFP flags in tests
  maple_tree: document erase and allocations better
  maple_tree: avoid mas_erase() and mtree_erase() failures
  maple_tree: document that erase may use GFP_KERNEL for allocations
  maple_tree: catch race in mas_alloc_cyclic()
  maple_tree: add bulk parent set helper
  maple_tree: micro optimisation of mas_wr_store_type()
  maple_tree: optimise mas_wr_node_store() when not in rcu mode
  maple_tree: use prefetched value in mas_wr_store_type()
  maple_tree: clarify comments on mas_nomem()
  maple_tree: drop MAPLE_ALLOC_SLOTS
  maple_tree: drop dead code from mas_extend_spanning_null()
  maple_tree: documentation fix
  maple_tree: add write lock checking with lockdep sequence numbers
  ...

1 files changed, 99 insertions, 0 deletions

diff --git a/include/uapi/linux/alloc_tag.h b/include/uapi/linux/alloc_tag.h
new file mode 100644
index 000000000000..e3ad94444864
--- /dev/null
+++ b/include/uapi/linux/alloc_tag.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * alloc_tag IOCTL API definition
+ *
+ * Copyright (C) 2026 Google, LLC.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _UAPI_ALLOC_TAG_H
+#define _UAPI_ALLOC_TAG_H
+
+#include <linux/types.h>
+
+/*
+ * Function, file and module names often have the same prefixes, therefore
+ * when filtering by these criteria, we compare the last 64 characters to
+ * minimize the chances of name collisions
+ */
+#define ALLOCINFO_STR_SIZE	64
+
+struct allocinfo_content_id {
+	__u64 id;
+};
+
+struct allocinfo_tag {
+	/* Longer names are trimmed */
+	char modname[ALLOCINFO_STR_SIZE];
+	char function[ALLOCINFO_STR_SIZE];
+	char filename[ALLOCINFO_STR_SIZE];
+	__u64 lineno;
+};
+
+/* The alignment ensures 32-bit compatible interfaces are not broken */
+struct allocinfo_counter {
+	__u64 bytes;
+	__u64 calls;
+	__u8 accurate;
+} __attribute__((aligned(8)));
+
+struct allocinfo_tag_data {
+	struct allocinfo_tag tag;
+	struct allocinfo_counter counter;
+};
+
+enum {
+	ALLOCINFO_FILTER_MODNAME,
+	ALLOCINFO_FILTER_FUNCTION,
+	ALLOCINFO_FILTER_FILENAME,
+	ALLOCINFO_FILTER_LINENO,
+	ALLOCINFO_FILTER_INACCURATE,
+	ALLOCINFO_FILTER_MIN_SIZE,
+	ALLOCINFO_FILTER_MAX_SIZE,
+	__ALLOCINFO_FILTER_LAST = ALLOCINFO_FILTER_MAX_SIZE
+};
+
+#define ALLOCINFO_FILTER_MASK_MODNAME		(1 << ALLOCINFO_FILTER_MODNAME)
+#define ALLOCINFO_FILTER_MASK_FUNCTION		(1 << ALLOCINFO_FILTER_FUNCTION)
+#define ALLOCINFO_FILTER_MASK_FILENAME		(1 << ALLOCINFO_FILTER_FILENAME)
+#define ALLOCINFO_FILTER_MASK_LINENO		(1 << ALLOCINFO_FILTER_LINENO)
+#define ALLOCINFO_FILTER_MASK_INACCURATE	(1 << ALLOCINFO_FILTER_INACCURATE)
+#define ALLOCINFO_FILTER_MASK_MIN_SIZE		(1 << ALLOCINFO_FILTER_MIN_SIZE)
+#define ALLOCINFO_FILTER_MASK_MAX_SIZE		(1 << ALLOCINFO_FILTER_MAX_SIZE)
+
+#define ALLOCINFO_FILTER_MASKS \
+	((1 << (__ALLOCINFO_FILTER_LAST + 1)) - 1)
+
+struct allocinfo_filter {
+	__u64 mask; /* bitmask of the filter fields used */
+	struct allocinfo_tag fields;
+	__u64 min_size;
+	__u64 max_size;
+	/* filter criteria only; see allocinfo_counter.accurate for actual accuracy */
+	__u64 inaccurate;
+};
+
+struct allocinfo_get_at {
+	/* inputs */
+	__u64 pos;
+	struct allocinfo_filter filter;
+	/* output */
+	struct allocinfo_tag_data data;
+};
+
+#define _ALLOCINFO_IOC_CONTENT_ID	0
+#define _ALLOCINFO_IOC_GET_AT		1
+#define _ALLOCINFO_IOC_GET_NEXT		2
+
+#define ALLOCINFO_IOC_BASE		0xA6
+#define ALLOCINFO_IOC_CONTENT_ID	_IOR(ALLOCINFO_IOC_BASE, _ALLOCINFO_IOC_CONTENT_ID,	\
+					     struct allocinfo_content_id)
+#define ALLOCINFO_IOC_GET_AT		_IOWR(ALLOCINFO_IOC_BASE, _ALLOCINFO_IOC_GET_AT,	\
+					      struct allocinfo_get_at)
+#define ALLOCINFO_IOC_GET_NEXT		_IOR(ALLOCINFO_IOC_BASE, _ALLOCINFO_IOC_GET_NEXT,	\
+					     struct allocinfo_tag_data)
+
+#endif /* _UAPI_ALLOC_TAG_H */