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
  ...

3 files changed, 0 insertions, 379 deletions

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 43f20ca95a2a..a9acf4575f4f 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -230,13 +230,6 @@ config GENERIC_ARCH_TOPOLOGY
 	  appropriate scaling, sysfs interface for reading capacity values at
 	  runtime.
 
-config GENERIC_ARCH_NUMA
-	bool
-	select NUMA_MEMBLKS
-	help
-	  Enable support for generic NUMA implementation. Currently, RISC-V
-	  and ARM64 use it.
-
 config FW_DEVLINK_SYNC_STATE_TIMEOUT
 	bool "sync_state() behavior defaults to timeout instead of strict"
 	help
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 8074a10183dc..435710f643a5 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -25,7 +25,6 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o
 obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
 obj-$(CONFIG_GENERIC_MSI_IRQ) += platform-msi.o
 obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
-obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
 obj-$(CONFIG_ACPI) += physical_location.o
 
 obj-y			+= test/
diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c
deleted file mode 100644
index 6476227b772c..000000000000
--- a/drivers/base/arch_numa.c
+++ /dev/null
@@ -1,371 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * NUMA support, based on the x86 implementation.
- *
- * Copyright (C) 2015 Cavium Inc.
- * Author: Ganapatrao Kulkarni <gkulkarni@cavium.com>
- */
-
-#define pr_fmt(fmt) "NUMA: " fmt
-
-#include <linux/acpi.h>
-#include <linux/memblock.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/numa_memblks.h>
-
-#include <asm/sections.h>
-
-static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
-
-bool numa_off;
-
-static __init int numa_parse_early_param(char *opt)
-{
-	if (!opt)
-		return -EINVAL;
-	if (str_has_prefix(opt, "off"))
-		numa_off = true;
-	if (!strncmp(opt, "fake=", 5))
-		return numa_emu_cmdline(opt + 5);
-
-	return 0;
-}
-early_param("numa", numa_parse_early_param);
-
-cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
-EXPORT_SYMBOL(node_to_cpumask_map);
-
-#ifdef CONFIG_DEBUG_PER_CPU_MAPS
-
-/*
- * Returns a pointer to the bitmask of CPUs on Node 'node'.
- */
-const struct cpumask *cpumask_of_node(int node)
-{
-
-	if (node == NUMA_NO_NODE)
-		return cpu_all_mask;
-
-	if (WARN_ON(node < 0 || node >= nr_node_ids))
-		return cpu_none_mask;
-
-	if (WARN_ON(node_to_cpumask_map[node] == NULL))
-		return cpu_online_mask;
-
-	return node_to_cpumask_map[node];
-}
-EXPORT_SYMBOL(cpumask_of_node);
-
-#endif
-
-#ifndef CONFIG_NUMA_EMU
-static void numa_update_cpu(unsigned int cpu, bool remove)
-{
-	int nid = cpu_to_node(cpu);
-
-	if (nid == NUMA_NO_NODE)
-		return;
-
-	if (remove)
-		cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
-	else
-		cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
-}
-
-void numa_add_cpu(unsigned int cpu)
-{
-	numa_update_cpu(cpu, false);
-}
-
-void numa_remove_cpu(unsigned int cpu)
-{
-	numa_update_cpu(cpu, true);
-}
-#endif
-
-void numa_clear_node(unsigned int cpu)
-{
-	numa_remove_cpu(cpu);
-	set_cpu_numa_node(cpu, NUMA_NO_NODE);
-}
-
-/*
- * Allocate node_to_cpumask_map based on number of available nodes
- * Requires node_possible_map to be valid.
- *
- * Note: cpumask_of_node() is not valid until after this is done.
- * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
- */
-static void __init setup_node_to_cpumask_map(void)
-{
-	int node;
-
-	/* setup nr_node_ids if not done yet */
-	if (nr_node_ids == MAX_NUMNODES)
-		setup_nr_node_ids();
-
-	/* allocate and clear the mapping */
-	for (node = 0; node < nr_node_ids; node++) {
-		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
-		cpumask_clear(node_to_cpumask_map[node]);
-	}
-
-	/* cpumask_of_node() will now work */
-	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
-}
-
-/*
- * Set the cpu to node and mem mapping
- */
-void numa_store_cpu_info(unsigned int cpu)
-{
-	set_cpu_numa_node(cpu, cpu_to_node_map[cpu]);
-}
-
-void __init early_map_cpu_to_node(unsigned int cpu, int nid)
-{
-	/* fallback to node 0 */
-	if (nid < 0 || nid >= MAX_NUMNODES || numa_off)
-		nid = 0;
-
-	cpu_to_node_map[cpu] = nid;
-
-	/*
-	 * We should set the numa node of cpu0 as soon as possible, because it
-	 * has already been set up online before. cpu_to_node(0) will soon be
-	 * called.
-	 */
-	if (!cpu)
-		set_cpu_numa_node(cpu, nid);
-}
-
-#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
-unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(__per_cpu_offset);
-
-int early_cpu_to_node(int cpu)
-{
-	return cpu_to_node_map[cpu];
-}
-
-static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
-{
-	return node_distance(early_cpu_to_node(from), early_cpu_to_node(to));
-}
-
-void __init setup_per_cpu_areas(void)
-{
-	unsigned long delta;
-	unsigned int cpu;
-	int rc = -EINVAL;
-
-	if (pcpu_chosen_fc != PCPU_FC_PAGE) {
-		/*
-		 * Always reserve area for module percpu variables.  That's
-		 * what the legacy allocator did.
-		 */
-		rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
-					    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
-					    pcpu_cpu_distance,
-					    early_cpu_to_node);
-#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
-		if (rc < 0)
-			pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n",
-				   pcpu_fc_names[pcpu_chosen_fc], rc);
-#endif
-	}
-
-#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
-	if (rc < 0)
-		rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, early_cpu_to_node);
-#endif
-	if (rc < 0)
-		panic("Failed to initialize percpu areas (err=%d).", rc);
-
-	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
-	for_each_possible_cpu(cpu)
-		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
-}
-#endif
-
-/*
- * Initialize NODE_DATA for a node on the local memory
- */
-static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
-{
-	if (start_pfn >= end_pfn)
-		pr_info("Initmem setup node %d [<memory-less node>]\n", nid);
-
-	alloc_node_data(nid);
-
-	NODE_DATA(nid)->node_id = nid;
-	NODE_DATA(nid)->node_start_pfn = start_pfn;
-	NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
-}
-
-static int __init numa_register_nodes(void)
-{
-	int nid;
-
-	/* Check the validity of the memblock/node mapping */
-	if (!memblock_validate_numa_coverage(0))
-		return -EINVAL;
-
-	/* Finally register nodes. */
-	for_each_node_mask(nid, numa_nodes_parsed) {
-		unsigned long start_pfn, end_pfn;
-
-		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
-		setup_node_data(nid, start_pfn, end_pfn);
-		node_set_online(nid);
-	}
-
-	return 0;
-}
-
-static int __init numa_init(int (*init_func)(void))
-{
-	int ret;
-
-	ret = numa_memblks_init(init_func, /* memblock_force_top_down */ false);
-	if (ret < 0)
-		goto out_free_distance;
-
-	if (nodes_empty(numa_nodes_parsed)) {
-		pr_info("No NUMA configuration found\n");
-		ret = -EINVAL;
-		goto out_free_distance;
-	}
-
-	ret = numa_register_nodes();
-	if (ret < 0)
-		goto out_free_distance;
-
-	setup_node_to_cpumask_map();
-
-	return 0;
-out_free_distance:
-	numa_reset_distance();
-	return ret;
-}
-
-/**
- * dummy_numa_init() - Fallback dummy NUMA init
- *
- * Used if there's no underlying NUMA architecture, NUMA initialization
- * fails, or NUMA is disabled on the command line.
- *
- * Must online at least one node (node 0) and add memory blocks that cover all
- * allowed memory. It is unlikely that this function fails.
- *
- * Return: 0 on success, -errno on failure.
- */
-static int __init dummy_numa_init(void)
-{
-	phys_addr_t start = memblock_start_of_DRAM();
-	phys_addr_t end = memblock_end_of_DRAM() - 1;
-	int ret;
-
-	if (numa_off)
-		pr_info("NUMA disabled\n"); /* Forced off on command line. */
-	pr_info("Faking a node at [mem %pap-%pap]\n", &start, &end);
-
-	ret = numa_add_memblk(0, start, end + 1);
-	if (ret) {
-		pr_err("NUMA init failed\n");
-		return ret;
-	}
-
-	numa_off = true;
-	return 0;
-}
-
-#ifdef CONFIG_ACPI_NUMA
-static int __init arch_acpi_numa_init(void)
-{
-	int ret;
-
-	ret = acpi_numa_init();
-	if (ret) {
-		pr_debug("Failed to initialise from firmware\n");
-		return ret;
-	}
-
-	return srat_disabled() ? -EINVAL : 0;
-}
-#else
-static int __init arch_acpi_numa_init(void)
-{
-	return -EOPNOTSUPP;
-}
-#endif
-
-/**
- * arch_numa_init() - Initialize NUMA
- *
- * Try each configured NUMA initialization method until one succeeds. The
- * last fallback is dummy single node config encompassing whole memory.
- */
-void __init arch_numa_init(void)
-{
-	if (!numa_off) {
-		if (!acpi_disabled && !numa_init(arch_acpi_numa_init))
-			return;
-		if (acpi_disabled && !numa_init(of_numa_init))
-			return;
-	}
-
-	numa_init(dummy_numa_init);
-}
-
-#ifdef CONFIG_NUMA_EMU
-void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
-					unsigned int nr_emu_nids)
-{
-	int i, j;
-
-	/*
-	 * Transform cpu_to_node_map table to use emulated nids by
-	 * reverse-mapping phys_nid.  The maps should always exist but fall
-	 * back to zero just in case.
-	 */
-	for (i = 0; i < ARRAY_SIZE(cpu_to_node_map); i++) {
-		if (cpu_to_node_map[i] == NUMA_NO_NODE)
-			continue;
-		for (j = 0; j < nr_emu_nids; j++)
-			if (cpu_to_node_map[i] == emu_nid_to_phys[j])
-				break;
-		cpu_to_node_map[i] = j < nr_emu_nids ? j : 0;
-	}
-}
-
-u64 __init numa_emu_dma_end(void)
-{
-	return memblock_start_of_DRAM() + SZ_4G;
-}
-
-void debug_cpumask_set_cpu(unsigned int cpu, int node, bool enable)
-{
-	struct cpumask *mask;
-
-	if (node == NUMA_NO_NODE)
-		return;
-
-	mask = node_to_cpumask_map[node];
-	if (!cpumask_available(mask)) {
-		pr_err("node_to_cpumask_map[%i] NULL\n", node);
-		dump_stack();
-		return;
-	}
-
-	if (enable)
-		cpumask_set_cpu(cpu, mask);
-	else
-		cpumask_clear_cpu(cpu, mask);
-
-	pr_debug("%s cpu %d node %d: mask now %*pbl\n",
-		 enable ? "numa_add_cpu" : "numa_remove_cpu",
-		 cpu, node, cpumask_pr_args(mask));
-}
-#endif /* CONFIG_NUMA_EMU */