linux/drivers/base/node.c, branch v6.16

Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-05-31T22:44:16Z

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 ...

mm/mempolicy: Weighted Interleave Auto-tuning

2025-05-21T16:55:15Z

On machines with multiple memory nodes, interleaving page allocations across nodes allows for better utilization of each node's bandwidth. Previous work by Gregory Price [1] introduced weighted interleave, which allowed for pages to be allocated across nodes according to user-set ratios. Ideally, these weights should be proportional to their bandwidth, so that under bandwidth pressure, each node uses its maximal efficient bandwidth and prevents latency from increasing exponentially. Previously, weighted interleave's default weights were just 1s -- which would be equivalent to the (unweighted) interleave mempolicy, which goes through the nodes in a round-robin fashion, ignoring bandwidth information. This patch has two main goals: First, it makes weighted interleave easier to use for users who wish to relieve bandwidth pressure when using nodes with varying bandwidth (CXL). By providing a set of "real" default weights that just work out of the box, users who might not have the capability (or wish to) perform experimentation to find the most optimal weights for their system can still take advantage of bandwidth-informed weighted interleave. Second, it allows for weighted interleave to dynamically adjust to hotplugged memory with new bandwidth information. Instead of manually updating node weights every time new bandwidth information is reported or taken off, weighted interleave adjusts and provides a new set of default weights for weighted interleave to use when there is a change in bandwidth information. To meet these goals, this patch introduces an auto-configuration mode for the interleave weights that provides a reasonable set of default weights, calculated using bandwidth data reported by the system. In auto mode, weights are dynamically adjusted based on whatever the current bandwidth information reports (and responds to hotplug events). This patch still supports users manually writing weights into the nodeN sysfs interface by entering into manual mode. When a user enters manual mode, the system stops dynamically updating any of the node weights, even during hotplug events that shift the optimal weight distribution. A new sysfs interface "auto" is introduced, which allows users to switch between the auto (writing 1 or Y) and manual (writing 0 or N) modes. The system also automatically enters manual mode when a nodeN interface is manually written to. There is one functional change that this patch makes to the existing weighted_interleave ABI: previously, writing 0 directly to a nodeN interface was said to reset the weight to the system default. Before this patch, the default for all weights were 1, which meant that writing 0 and 1 were functionally equivalent. With this patch, writing 0 is invalid. Link: https://lkml.kernel.org/r/20250520141236.2987309-1-joshua.hahnjy@gmail.com [joshua.hahnjy@gmail.com: wordsmithing changes, simplification, fixes] Link: https://lkml.kernel.org/r/20250511025840.2410154-1-joshua.hahnjy@gmail.com [joshua.hahnjy@gmail.com: remove auto_kobj_attr field from struct sysfs_wi_group] Link: https://lkml.kernel.org/r/20250512142511.3959833-1-joshua.hahnjy@gmail.com https://lore.kernel.org/linux-mm/20240202170238.90004-1-gregory.price@memverge.com/ [1] Link: https://lkml.kernel.org/r/20250505182328.4148265-1-joshua.hahnjy@gmail.com Co-developed-by: Gregory Price Signed-off-by: Gregory Price Signed-off-by: Joshua Hahn Suggested-by: Yunjeong Mun Suggested-by: Oscar Salvador Suggested-by: Ying Huang Suggested-by: Harry Yoo Reviewed-by: Harry Yoo Reviewed-by: Huang Ying Reviewed-by: Honggyu Kim Cc: Dan Williams Cc: Dave Jiang Cc: Greg Kroah-Hartman Cc: Joanthan Cameron Cc: Johannes Weiner Cc: Len Brown Signed-off-by: Andrew Morton

mm: remove NR_BOUNCE zone stat

2025-05-05T19:22:39Z

The stat is always 0 now, so remove it and hardwire the user visible output to 0. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250505081138.3435992-8-hch@lst.de Signed-off-by: Jens Axboe

acpi: numa: Add support to enumerate and store extended linear address mode

2025-02-26T20:45:22Z

Store the address mode as part of the cache attriutes. Export the mode attribute to sysfs as all other cache attributes. Link: https://lore.kernel.org/linux-cxl/668333b17e4b2_5639294fd@dwillia2-xfh.jf.intel.com.notmuch/ Reviewed-by: Jonathan Cameron Reviewed-by: Li Ming Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20250226162224.3633792-2-dave.jiang@intel.com Signed-off-by: Dave Jiang

driver core: Constify bin_attribute definitions

2024-11-15T18:29:16Z

Mark all 'struct bin_attribute' instances as const to protect against accidental and malicious modifications. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20241115-b4-sysfs-const-bin_attr-group-v1-2-2c9bb12dfc48@weissschuh.net Signed-off-by: Greg Kroah-Hartman

driver core: Constify attribute arguments of binary attributes

2024-11-05T13:00:28Z

As preparation for the constification of struct bin_attribute, constify the arguments of the read and write callbacks. Signed-off-by: Thomas Weißschuh Acked-by: Krzysztof Wilczyński Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-10-71110628844c@weissschuh.net Signed-off-by: Greg Kroah-Hartman

cxl/region: Deal with numa nodes not enumerated by SRAT

2024-03-12T21:54:03Z

For the numa nodes that are not created by SRAT, no memory_target is allocated and is not managed by the HMAT_REPORTING code. Therefore hmat_callback() memory hotplug notifier will exit early on those NUMA nodes. The CXL memory hotplug notifier will need to call node_set_perf_attrs() directly in order to setup the access sysfs attributes. In acpi_numa_init(), the last proximity domain (pxm) id created by SRAT is stored. Add a helper function acpi_node_backed_by_real_pxm() in order to check if a NUMA node id is defined by SRAT or created by CFMWS. node_set_perf_attrs() symbol is exported to allow update of perf attribs for a node. The sysfs path of /sys/devices/system/node/nodeX/access0/initiators/* is created by node_set_perf_attrs() for the various attributes where nodeX is matched to the NUMA node of the CXL region. Cc: Rafael J. Wysocki Reviewed-by: Alison Schofield Reviewed-by: Jonathan Cameron Tested-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/20240308220055.2172956-13-dave.jiang@intel.com Signed-off-by: Dan Williams

base/node / ACPI: Enumerate node access class for 'struct access_coordinate'

2024-03-12T19:34:11Z

Both generic node and HMAT handling code have been using magic numbers to indicate access classes for 'struct access_coordinate'. Introduce enums to enumerate the access0 and access1 classes shared by the two subsystems. Update the function parameters and callers as appropriate to utilize the new enum. Access0 is named to ACCESS_COORDINATE_LOCAL in order to indicate that the access class is for 'struct access_coordinate' between a target node and the nearest initiator node. Access1 is named to ACCESS_COORDINATE_CPU in order to indicate that the access class is for 'struct access_coordinate' between a target node and the nearest CPU node. Cc: Greg Kroah-Hartman Cc: Rafael J. Wysocki Reviewed-by: Jonathan Cameron Tested-by: Jonathan Cameron Acked-by: Greg Kroah-Hartman Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/20240308220055.2172956-3-dave.jiang@intel.com Signed-off-by: Dan Williams

Merge tag 'cxl-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2024-01-19T00:22:43Z

Pull CXL (Compute Express Link) updates from Dan Williams: "The bulk of this update is support for enumerating the performance capabilities of CXL memory targets and connecting that to a platform CXL memory QoS class. Some follow-on work remains to hook up this data into core-mm policy, but that is saved for v6.9. The next significant update is unifying how CXL event records (things like background scrub errors) are processed between so called "firmware first" and native error record retrieval. The CXL driver handler that processes the record retrieved from the device mailbox is now the handler for that same record format coming from an EFI/ACPI notification source. This also contains miscellaneous feature updates, like Get Timestamp, and other fixups. Summary: - Add support for parsing the Coherent Device Attribute Table (CDAT) - Add support for calculating a platform CXL QoS class from CDAT data - Unify the tracing of EFI CXL Events with native CXL Events. - Add Get Timestamp support - Miscellaneous cleanups and fixups" * tag 'cxl-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (41 commits) cxl/core: use sysfs_emit() for attr's _show() cxl/pci: Register for and process CPER events PCI: Introduce cleanup helpers for device reference counts and locks acpi/ghes: Process CXL Component Events cxl/events: Create a CXL event union cxl/events: Separate UUID from event structures cxl/events: Remove passing a UUID to known event traces cxl/events: Create common event UUID defines cxl/events: Promote CXL event structures to a core header cxl: Refactor to use __free() for cxl_root allocation in cxl_endpoint_port_probe() cxl: Refactor to use __free() for cxl_root allocation in cxl_find_nvdimm_bridge() cxl: Fix device reference leak in cxl_port_perf_data_calculate() cxl: Convert find_cxl_root() to return a 'struct cxl_root *' cxl: Introduce put_cxl_root() helper cxl/port: Fix missing target list lock cxl/port: Fix decoder initialization when nr_targets > interleave_ways cxl/region: fix x9 interleave typo cxl/trace: Pass UUID explicitly to event traces cxl/region: use %pap format to print resource_size_t cxl/region: Add dev_dbg() detail on failure to allocate HPA space ...

base/node / acpi: Change 'node_hmem_attrs' to 'access_coordinates'

2023-12-22T22:23:13Z

Dan Williams suggested changing the struct 'node_hmem_attrs' to 'access_coordinates' [1]. The struct is a container of r/w-latency and r/w-bandwidth numbers. Moving forward, this container will also be used by CXL to store the performance characteristics of each link hop in the PCIE/CXL topology. So, where node_hmem_attrs is just the access parameters of a memory-node, access_coordinates applies more broadly to hardware topology characteristics. The observation is that seemed like an exercise in having the application identify "where" it falls on a spectrum of bandwidth and latency needs. For the tuple of read/write-latency and read/write-bandwidth, "coordinates" is not a perfect fit. Sometimes it is just conveying values in isolation and not a "location" relative to other performance points, but in the end this data is used to identify the performance operation point of a given memory-node. [2] Link: http://lore.kernel.org/r/64471313421f7_1b66294d5@dwillia2-xfh.jf.intel.com.notmuch/ Link: https://lore.kernel.org/linux-cxl/645e6215ee0de_1e6f2945e@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams Reviewed-by: Dan Williams Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/170319615734.2212653.15319394025985499185.stgit@djiang5-mobl3 Signed-off-by: Dan Williams