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4 daysMerge tag 'mm-stable-2026-04-13-21-45' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...
12 daysfs/resctrl: Add missing return value descriptionsReinette Chatre
Using the stricter "./tools/docs/kernel-doc -Wall -v" to verify proper formatting of documentation comments includes warnings related to return markup on functions that are omitted during the default verification checks. This stricter verification reports a couple of missing return descriptions in resctrl: Warning: .../fs/resctrl/rdtgroup.c:1536 No description found for return value of 'rdtgroup_cbm_to_size' Warning: .../fs/resctrl/rdtgroup.c:3131 No description found for return value of 'mon_get_kn_priv' Warning: .../fs/resctrl/rdtgroup.c:3523 No description found for return value of 'cbm_ensure_valid' Warning: .../fs/resctrl/monitor.c:238 No description found for return value of 'resctrl_find_cleanest_closid' Add the missing return descriptions. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/1c50b9f7c73251c007133590986f127e1af57780.1775576382.git.reinette.chatre@intel.com
14 daysmm: reintroduce vma_desc_test() as a singular flag testLorenzo Stoakes (Oracle)
Similar to vma_flags_test(), we have previously renamed vma_desc_test() to vma_desc_test_any(). Now that is in place, we can reintroduce vma_desc_test() to explicitly check for a single VMA flag. As with vma_flags_test(), this is useful as often flag tests are against a single flag, and vma_desc_test_any(flags, VMA_READ_BIT) reads oddly and potentially causes confusion. As with vma_flags_test() a combination of sparse and vma_flags_t being a struct means that users cannot misuse this function without it getting flagged. Also update the VMA tests to reflect this change. Link: https://lkml.kernel.org/r/3a65ca23defb05060333f0586428fe279a484564.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Babu Moger <babu.moger@amd.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chao Yu <chao@kernel.org> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Chunhai Guo <guochunhai@vivo.com> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hongbo Li <lihongbo22@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naohiro Aota <naohiro.aota@wdc.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sandeep Dhavale <dhavale@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Yue Hu <zbestahu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
14 daysmm: rename VMA flag helpers to be more readableLorenzo Stoakes (Oracle)
Patch series "mm: vma flag tweaks". The ongoing work around introducing non-system word VMA flags has introduced a number of helper functions and macros to make life easier when working with these flags and to make conversions from the legacy use of VM_xxx flags more straightforward. This series improves these to reduce confusion as to what they do and to improve consistency and readability. Firstly the series renames vma_flags_test() to vma_flags_test_any() to make it abundantly clear that this function tests whether any of the flags are set (as opposed to vma_flags_test_all()). It then renames vma_desc_test_flags() to vma_desc_test_any() for the same reason. Note that we drop the 'flags' suffix here, as vma_desc_test_any_flags() would be cumbersome and 'test' implies a flag test. Similarly, we rename vma_test_all_flags() to vma_test_all() for consistency. Next, we have a couple of instances (erofs, zonefs) where we are now testing for vma_desc_test_any(desc, VMA_SHARED_BIT) && vma_desc_test_any(desc, VMA_MAYWRITE_BIT). This is silly, so this series introduces vma_desc_test_all() so these callers can instead invoke vma_desc_test_all(desc, VMA_SHARED_BIT, VMA_MAYWRITE_BIT). We then observe that quite a few instances of vma_flags_test_any() and vma_desc_test_any() are in fact only testing against a single flag. Using the _any() variant here is just confusing - 'any' of single item reads strangely and is liable to cause confusion. So in these instances the series reintroduces vma_flags_test() and vma_desc_test() as helpers which test against a single flag. The fact that vma_flags_t is a struct and that vma_flag_t utilises sparse to avoid confusion with vm_flags_t makes it impossible for a user to misuse these helpers without it getting flagged somewhere. The series also updates __mk_vma_flags() and functions invoked by it to explicitly mark them always inline to match expectation and to be consistent with other VMA flag helpers. It also renames vma_flag_set() to vma_flags_set_flag() (a function only used by __mk_vma_flags()) to be consistent with other VMA flag helpers. Finally it updates the VMA tests for each of these changes, and introduces explicit tests for vma_flags_test() and vma_desc_test() to assert that they behave as expected. This patch (of 6): On reflection, it's confusing to have vma_flags_test() and vma_desc_test_flags() test whether any comma-separated VMA flag bit is set, while also having vma_flags_test_all() and vma_test_all_flags() separately test whether all flags are set. Firstly, rename vma_flags_test() to vma_flags_test_any() to eliminate this confusion. Secondly, since the VMA descriptor flag functions are becoming rather cumbersome, prefer vma_desc_test*() to vma_desc_test_flags*(), and also rename vma_desc_test_flags() to vma_desc_test_any(). Finally, rename vma_test_all_flags() to vma_test_all() to keep the VMA-specific helper consistent with the VMA descriptor naming convention and to help avoid confusion vs. vma_flags_test_all(). While we're here, also update whitespace to be consistent in helper functions. Link: https://lkml.kernel.org/r/cover.1772704455.git.ljs@kernel.org Link: https://lkml.kernel.org/r/0f9cb3c511c478344fac0b3b3b0300bb95be95e9.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Suggested-by: Pedro Falcato <pfalcato@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Babu Moger <babu.moger@amd.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chao Yu <chao@kernel.org> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Chunhai Guo <guochunhai@vivo.com> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hongbo Li <lihongbo22@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naohiro Aota <naohiro.aota@wdc.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sandeep Dhavale <dhavale@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Yue Hu <zbestahu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-02fs/resctrl: Add "*" shorthand to set io_alloc CBM for all domainsAaron Tomlin
Configuring the io_alloc_cbm interface requires an explicit domain ID for each cache domain. On systems with high core counts and numerous cache clusters, this requirement becomes cumbersome for automation and management tasks that aim to apply a uniform policy. Introduce a wildcard domain ID selector "*" for the io_alloc_cbm interface. This enables users to set the same Capacity Bitmask (CBM) across all cache domains in a single operation. Signed-off-by: Aaron Tomlin <atomlin@atomlin.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Babu Moger <babu.moger@amd.com> Tested-by: Babu Moger <babu.moger@amd.com> Link: https://patch.msgid.link/20260325001159.447075-3-atomlin@atomlin.com
2026-04-02fs/resctrl: Report invalid domain ID when parsing io_alloc_cbmAaron Tomlin
The last_cmd_status file is intended to report details about the most recent resctrl filesystem operation, specifically to aid in diagnosing failures. However, when parsing io_alloc_cbm, if a user provides a domain ID that does not exist in the resource, the operation fails with -EINVAL without updating last_cmd_status. This results in inconsistent behaviour where the system call returns an error, but last_cmd_status misleadingly reports "ok", leaving the user unaware that the failure was caused by an invalid domain ID. Write an error message to last_cmd_status when the target domain ID cannot be found. Fixes: 28fa2cce7a83 ("fs/resctrl: Introduce interface to modify io_alloc capacity bitmasks") Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Aaron Tomlin <atomlin@atomlin.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Babu Moger <babu.moger@amd.com> Tested-by: Babu Moger <babu.moger@amd.com> Link: https://patch.msgid.link/20260325001159.447075-2-atomlin@atomlin.com
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-18Merge tag 'mm-stable-2026-02-18-19-48' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a couple of issues in the demotion code - pages were failed demotion and were finding themselves demoted into disallowed nodes (Bing Jiao) - "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare mapledtree race and performs a number of cleanups (Liam Howlett) - "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them" implements a lot of cleanups following on from the conversion of the VMA flags into a bitmap (Lorenzo Stoakes) - "support batch checking of references and unmapping for large folios" implements batching to greatly improve the performance of reclaiming clean file-backed large folios (Baolin Wang) - "selftests/mm: add memory failure selftests" does as claimed (Miaohe Lin) * tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits) mm/page_alloc: clear page->private in free_pages_prepare() selftests/mm: add memory failure dirty pagecache test selftests/mm: add memory failure clean pagecache test selftests/mm: add memory failure anonymous page test mm: rmap: support batched unmapping for file large folios arm64: mm: implement the architecture-specific clear_flush_young_ptes() arm64: mm: support batch clearing of the young flag for large folios arm64: mm: factor out the address and ptep alignment into a new helper mm: rmap: support batched checks of the references for large folios tools/testing/vma: add VMA userland tests for VMA flag functions tools/testing/vma: separate out vma_internal.h into logical headers tools/testing/vma: separate VMA userland tests into separate files mm: make vm_area_desc utilise vma_flags_t only mm: update all remaining mmap_prepare users to use vma_flags_t mm: update shmem_[kernel]_file_*() functions to use vma_flags_t mm: update secretmem to use VMA flags on mmap_prepare mm: update hugetlbfs to use VMA flags on mmap_prepare mm: add basic VMA flag operation helper functions tools: bitmap: add missing bitmap_[subset(), andnot()] mm: add mk_vma_flags() bitmap flag macro helper ...
2026-02-12mm: update all remaining mmap_prepare users to use vma_flags_tLorenzo Stoakes
We will be shortly removing the vm_flags_t field from vm_area_desc so we need to update all mmap_prepare users to only use the dessc->vma_flags field. This patch achieves that and makes all ancillary changes required to make this possible. This lays the groundwork for future work to eliminate the use of vm_flags_t in vm_area_desc altogether and more broadly throughout the kernel. While we're here, we take the opportunity to replace VM_REMAP_FLAGS with VMA_REMAP_FLAGS, the vma_flags_t equivalent. No functional changes intended. Link: https://lkml.kernel.org/r/fb1f55323799f09fe6a36865b31550c9ec67c225.1769097829.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Damien Le Moal <dlemoal@kernel.org> [zonefs] Acked-by: "Darrick J. Wong" <djwong@kernel.org> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Yury Norov <ynorov@nvidia.com> Cc: Chris Mason <clm@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-10fs/resctrl: Move RMID initialization to first mountTony Luck
L3 monitor features are enumerated during resctrl initialization and rmid_ptrs[] that tracks all RMIDs and depends on the number of supported RMIDs is allocated during this time. Telemetry monitor features are enumerated during first resctrl mount and may support a different number of RMIDs compared to L3 monitor features. Delay allocation and initialization of rmid_ptrs[] until first mount. Since the number of RMIDs cannot change on later mounts, keep the same set of rmid_ptrs[] until resctrl_exit(). This is required because the limbo handler keeps running after resctrl is unmounted and needs to access rmid_ptrs[] as it keeps tracking busy RMIDs after unmount. Rename routines to match what they now do: dom_data_init() -> setup_rmid_lru_list() dom_data_exit() -> free_rmid_lru_list() Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-10x86,fs/resctrl: Compute number of RMIDs as minimum across resourcesTony Luck
resctrl assumes that only the L3 resource supports monitor events, so it simply takes the rdt_resource::num_rmid from RDT_RESOURCE_L3 as the system's number of RMIDs. The addition of telemetry events in a different resource breaks that assumption. Compute the number of available RMIDs as the minimum value across all mon_capable resources (analogous to how the number of CLOSIDs is computed across alloc_capable resources). Note that mount time enumeration of the telemetry resource means that this number can be reduced. If this happens, then some memory will be wasted as the allocations for rdt_l3_mon_domain::mbm_states[] and rdt_l3_mon_domain::rmid_busy_llc created during resctrl initialization will be larger than needed. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-10fs/resctrl: Move allocation/free of closid_num_dirty_rmid[]Tony Luck
closid_num_dirty_rmid[] and rmid_ptrs[] are allocated together during resctrl initialization and freed together during resctrl exit. Telemetry events are enumerated on resctrl mount so only at resctrl mount will the number of RMID supported by all monitoring resources and needed as size for rmid_ptrs[] be known. Separate closid_num_dirty_rmid[] and rmid_ptrs[] allocation and free in preparation for rmid_ptrs[] to be allocated on resctrl mount. Keep the rdtgroup_mutex protection around the allocation and free of closid_num_dirty_rmid[] as ARM needs this to guarantee memory ordering. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-10x86/resctrl: Handle number of RMIDs supported by RDT_RESOURCE_PERF_PKGTony Luck
There are now three meanings for "number of RMIDs": 1) The number for legacy features enumerated by CPUID leaf 0xF. This is the maximum number of distinct values that can be loaded into MSR_IA32_PQR_ASSOC. Note that systems with Sub-NUMA Cluster mode enabled will force scaling down the CPUID enumerated value by the number of SNC nodes per L3-cache. 2) The number of registers in MMIO space for each event. This is enumerated in the XML files and is the value initialized into event_group::num_rmid. 3) The number of "hardware counters" (this isn't a strictly accurate description of how things work, but serves as a useful analogy that does describe the limitations) feeding to those MMIO registers. This is enumerated in telemetry_region::num_rmids returned by intel_pmt_get_regions_by_feature(). Event groups with insufficient "hardware counters" to track all RMIDs are difficult for users to use, since the system may reassign "hardware counters" at any time. This means that users cannot reliably collect two consecutive event counts to compute the rate at which events are occurring. Disable such event groups by default. The user may override this with a command line "rdt=" option. In this case limit an under-resourced event group's number of possible monitor resource groups to the lowest number of "hardware counters". Scan all enabled event groups and assign the RDT_RESOURCE_PERF_PKG resource "num_rmid" value to the smallest of these values as this value will be used later to compare against the number of RMIDs supported by other resources to determine how many monitoring resource groups are supported. N.B. Change type of resctrl_mon::num_rmid to u32 to match its usage and the type of event_group::num_rmid so that min(r->num_rmid, e->num_rmid) won't complain about mixing signed and unsigned types. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86,fs/resctrl: Handle domain creation/deletion for RDT_RESOURCE_PERF_PKGTony Luck
The L3 resource has several requirements for domains. There are per-domain structures that hold the 64-bit values of counters, and elements to keep track of the overflow and limbo threads. None of these are needed for the PERF_PKG resource. The hardware counters are wide enough that they do not wrap around for decades. Define a new rdt_perf_pkg_mon_domain structure which just consists of the standard rdt_domain_hdr to keep track of domain id and CPU mask. Update resctrl_online_mon_domain() for RDT_RESOURCE_PERF_PKG. The only action needed for this resource is to create and populate domain directories if a domain is added while resctrl is mounted. Similarly resctrl_offline_mon_domain() only needs to remove domain directories. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09fs/resctrl: Refactor rmdir_mondata_subdir_allrdtgrp()Tony Luck
Clearing a monitor group's mon_data directory is complicated because of the support for Sub-NUMA Cluster (SNC) mode. Refactor the SNC case into a helper function to make it easier to add support for a new telemetry resource. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09fs/resctrl: Refactor mkdir_mondata_subdir()Tony Luck
Population of a monitor group's mon_data directory is unreasonably complicated because of the support for Sub-NUMA Cluster (SNC) mode. Split out the SNC code into a helper function to make it easier to add support for a new telemetry resource. Move all the duplicated code to make and set owner of domain directories into the mon_add_all_files() helper and rename to _mkdir_mondata_subdir(). Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86/resctrl: Read telemetry eventsTony Luck
Introduce intel_aet_read_event() to read telemetry events for resource RDT_RESOURCE_PERF_PKG. There may be multiple aggregators tracking each package, so scan all of them and add up all counters. Aggregators may return an invalid data indication if they have received no records for a given RMID. The user will see "Unavailable" if none of the aggregators on a package provide valid counts. Resctrl now uses readq() so depends on X86_64. Update Kconfig. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86/resctrl: Find and enable usable telemetry eventsTony Luck
Every event group has a private copy of the data of all telemetry event aggregators (aka "telemetry regions") tracking its feature type. Included may be regions that have the same feature type but tracking different GUID from the event group's. Traverse the event group's telemetry region data and mark all regions that are not usable by the event group as unusable by clearing those regions' MMIO addresses. A region is considered unusable if: 1) GUID does not match the GUID of the event group. 2) Package ID is invalid. 3) The enumerated size of the MMIO region does not match the expected value from the XML description file. Hereafter any telemetry region with an MMIO address is considered valid for the event group it is associated with. Enable all the event group's events as long as there is at least one usable region from where data for its events can be read. Enabling of an event can fail if the same event has already been enabled as part of another event group. It should never happen that the same event is described by different GUID supported by the same system so just WARN (via resctrl_enable_mon_event()) and skip the event. Note that it is architecturally possible that some telemetry events are only supported by a subset of the packages in the system. It is not expected that systems will ever do this. If they do the user will see event files in resctrl that always return "Unavailable". Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86,fs/resctrl: Add architectural event pointerTony Luck
The resctrl file system layer passes the domain, RMID, and event id to the architecture to fetch an event counter. Fetching a telemetry event counter requires additional information that is private to the architecture, for example, the offset into MMIO space from where the counter should be read. Add mon_evt::arch_priv that architecture can use for any private data related to the event. The resctrl filesystem initializes mon_evt::arch_priv when the architecture enables the event and passes it back to architecture when needing to fetch an event counter. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86,fs/resctrl: Fill in details of events for performance and energy GUIDsTony Luck
The telemetry event aggregators of the Intel Clearwater Forest CPU support two RMID-based feature types: "energy" with GUID 0x26696143¹, and "perf" with GUID 0x26557651². The event counter offsets in an aggregator's MMIO space are arranged in groups for each RMID. E.g., the "energy" counters for GUID 0x26696143 are arranged like this: MMIO offset:0x0000 Counter for RMID 0 PMT_EVENT_ENERGY MMIO offset:0x0008 Counter for RMID 0 PMT_EVENT_ACTIVITY MMIO offset:0x0010 Counter for RMID 1 PMT_EVENT_ENERGY MMIO offset:0x0018 Counter for RMID 1 PMT_EVENT_ACTIVITY ... MMIO offset:0x23F0 Counter for RMID 575 PMT_EVENT_ENERGY MMIO offset:0x23F8 Counter for RMID 575 PMT_EVENT_ACTIVITY After all counters there are three status registers that provide indications of how many times an aggregator was unable to process event counts, the time stamp for the most recent loss of data, and the time stamp of the most recent successful update. MMIO offset:0x2400 AGG_DATA_LOSS_COUNT MMIO offset:0x2408 AGG_DATA_LOSS_TIMESTAMP MMIO offset:0x2410 LAST_UPDATE_TIMESTAMP Define event_group structures for both of these aggregator types and define the events tracked by the aggregators in the file system code. PMT_EVENT_ENERGY and PMT_EVENT_ACTIVITY are produced in fixed point format. File system code must output as floating point values. ¹https://github.com/intel/Intel-PMT/blob/main/xml/CWF/OOBMSM/RMID-ENERGY/cwf_aggregator.xml ²https://github.com/intel/Intel-PMT/blob/main/xml/CWF/OOBMSM/RMID-PERF/cwf_aggregator.xml [ bp: Massage commit message. ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09fs/resctrl: Emphasize that L3 monitoring resource is required for summing ↵Tony Luck
domains The feature to sum event data across multiple domains supports systems with Sub-NUMA Cluster (SNC) mode enabled. The top-level monitoring files in each "mon_L3_XX" directory provide the sum of data across all SNC nodes sharing an L3 cache instance while the "mon_sub_L3_YY" sub-directories provide the event data of the individual nodes. SNC is only associated with the L3 resource and domains and as a result the flow handling the sum of event data implicitly assumes it is working with the L3 resource and domains. Reading of telemetry events does not require to sum event data so this feature can remain dedicated to SNC and keep the implicit assumption of working with the L3 resource and domains. Add a WARN to where the implicit assumption of working with the L3 resource is made and add comments on how the structure controlling the event sum feature is used. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86,fs/resctrl: Add and initialize a resource for package scope monitoringTony Luck
Add a new PERF_PKG resource and introduce package level scope for monitoring telemetry events so that CPU hotplug notifiers can build domains at the package granularity. Use the physical package ID available via topology_physical_package_id() to identify the monitoring domains with package level scope. This enables user space to use: /sys/devices/system/cpu/cpuX/topology/physical_package_id to identify the monitoring domain a CPU is associated with. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-09x86,fs/resctrl: Add an architectural hook called for first mountTony Luck
Enumeration of Intel telemetry events is an asynchronous process involving several mutually dependent drivers added as auxiliary devices during the device_initcall() phase of Linux boot. The process finishes after the probe functions of these drivers completes. But this happens after resctrl_arch_late_init() is executed. Tracing the enumeration process shows that it does complete a full seven seconds before the earliest possible mount of the resctrl file system (when included in /etc/fstab for automatic mount by systemd). Add a hook for use by telemetry event enumeration and initialization and run it once at the beginning of resctrl mount without any locks held. The architecture is responsible for any required locking. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20260105191711.GBaVwON5nZn-uO6Sqg@fat_crate.local
2026-01-05x86,fs/resctrl: Support binary fixed point event countersTony Luck
resctrl assumes that all monitor events can be displayed as unsigned decimal integers. Hardware architecture counters may provide some telemetry events with greater precision where the event is not a simple count, but is a measurement of some sort (e.g. Joules for energy consumed). Add a new argument to resctrl_enable_mon_event() for architecture code to inform the file system that the value for a counter is a fixed-point value with a specific number of binary places. Only allow architecture to use floating point format on events that the file system has marked with mon_evt::is_floating_point which reflects the contract with user space on how the event values are displayed. Display fixed point values with values rounded to ceil(binary_bits * log10(2)) decimal places. Special case for zero binary bits to print "{value}.0". Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05x86,fs/resctrl: Handle events that can be read from any CPUTony Luck
resctrl assumes that monitor events can only be read from a CPU in the cpumask_t set of each domain. This is true for x86 events accessed with an MSR interface, but may not be true for other access methods such as MMIO. Introduce and use flag mon_evt::any_cpu, settable by architecture, that indicates there are no restrictions on which CPU can read that event. This flag is not supported by the L3 event reading that requires to be run on a CPU that belongs to the L3 domain of the event being read. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05fs/resctrl: Make event details accessible to functions when reading eventsTony Luck
Reading monitoring event data from MMIO requires more context than the event id to be able to read the correct memory location. struct mon_evt is the appropriate place for this event specific context. Prepare for addition of extra fields to struct mon_evt by changing the calling conventions to pass a pointer to the mon_evt structure instead of just the event id. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05x86,fs/resctrl: Rename some L3 specific functionsTony Luck
With the arrival of monitor events tied to new domains associated with a different resource it would be clearer if the L3 resource specific functions are more accurately named. Rename three groups of functions: Functions that allocate/free architecture per-RMID MBM state information: arch_domain_mbm_alloc() -> l3_mon_domain_mbm_alloc() mon_domain_free() -> l3_mon_domain_free() Functions that allocate/free filesystem per-RMID MBM state information: domain_setup_mon_state() -> domain_setup_l3_mon_state() domain_destroy_mon_state() -> domain_destroy_l3_mon_state() Initialization/exit: rdt_get_mon_l3_config() -> rdt_get_l3_mon_config() resctrl_mon_resource_init() -> resctrl_l3_mon_resource_init() resctrl_mon_resource_exit() -> resctrl_l3_mon_resource_exit() Ensure kernel-doc descriptions of these functions' return values are present and correctly formatted. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05x86,fs/resctrl: Rename struct rdt_mon_domain and rdt_hw_mon_domainTony Luck
The upcoming telemetry event monitoring is not tied to the L3 resource and will have a new domain structure. Rename the L3 resource specific domain data structures to include "l3_" in their names to avoid confusion between the different resource specific domain structures: rdt_mon_domain -> rdt_l3_mon_domain rdt_hw_mon_domain -> rdt_hw_l3_mon_domain No functional change. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05x86,fs/resctrl: Use struct rdt_domain_hdr when reading countersTony Luck
Convert the whole call sequence from mon_event_read() to resctrl_arch_rmid_read() to pass resource independent struct rdt_domain_hdr instead of an L3 specific domain structure to prepare for monitoring events in other resources. This additional layer of indirection obscures which aspects of event counting depend on a valid domain. Event initialization, support for assignable counters, and normal event counting implicitly depend on a valid domain while summing of domains does not. Split summing domains from the core event counting handling to make their respective dependencies obvious. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-05fs/resctrl: Split L3 dependent parts out of __mon_event_count()Tony Luck
Carve out the L3 resource specific event reading code into a separate helper to support reading event data from a new monitoring resource. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-04x86,fs/resctrl: Refactor domain create/remove using struct rdt_domain_hdrTony Luck
Up until now, all monitoring events were associated with the L3 resource and it made sense to use the L3 specific "struct rdt_mon_domain *" argument to functions operating on domains. Telemetry events will be tied to a new resource with its instances represented by a new domain structure that, just like struct rdt_mon_domain, starts with the generic struct rdt_domain_hdr. Prepare to support domains belonging to different resources by changing the calling convention of functions operating on domains. Pass the generic header and use that to find the domain specific structure where needed. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-04x86,fs/resctrl: Improve domain type checkingTony Luck
Every resctrl resource has a list of domain structures. struct rdt_ctrl_domain and struct rdt_mon_domain both begin with struct rdt_domain_hdr with rdt_domain_hdr::type used in validity checks before accessing the domain of a particular type. Add the resource id to struct rdt_domain_hdr in preparation for a new monitoring domain structure that will be associated with a new monitoring resource. Improve existing domain validity checks with a new helper domain_header_is_valid() that checks both domain type and resource id. domain_header_is_valid() should be used before every call to container_of() that accesses a domain structure. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2025-12-05Merge tag 'mm-stable-2025-12-03-21-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki) Rework the vmalloc() code to support non-blocking allocations (GFP_ATOIC, GFP_NOWAIT) "ksm: fix exec/fork inheritance" (xu xin) Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not inherited across fork/exec "mm/zswap: misc cleanup of code and documentations" (SeongJae Park) Some light maintenance work on the zswap code "mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira) Enhance the /sys/kernel/debug/page_owner debug feature by adding unique identifiers to differentiate the various stack traces so that userspace monitoring tools can better match stack traces over time "mm/page_alloc: pcp->batch cleanups" (Joshua Hahn) Minor alterations to the page allocator's per-cpu-pages feature "Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra) Address a scalability issue in userfaultfd's UFFDIO_MOVE operation "kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov) "drivers/base/node: fold node register and unregister functions" (Donet Tom) Clean up the NUMA node handling code a little "mm: some optimizations for prot numa" (Kefeng Wang) Cleanups and small optimizations to the NUMA allocation hinting code "mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn) Address long lock hold times at boot on large machines. These were causing (harmless) softlockup warnings "optimize the logic for handling dirty file folios during reclaim" (Baolin Wang) Remove some now-unnecessary work from page reclaim "mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park) Enhance the DAMOS auto-tuning feature "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan) Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace configuration "expand mmap_prepare functionality, port more users" (Lorenzo Stoakes) Enhance the new(ish) file_operations.mmap_prepare() method and port additional callsites from the old ->mmap() over to ->mmap_prepare() "Fix stale IOTLB entries for kernel address space" (Lu Baolu) Fix a bug (and possible security issue on non-x86) in the IOMMU code. In some situations the IOMMU could be left hanging onto a stale kernel pagetable entry "mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang) Clean up and optimize the folio splitting code "mm, swap: misc cleanup and bugfix" (Kairui Song) Some cleanups and a minor fix in the swap discard code "mm/damon: misc documentation fixups" (SeongJae Park) "mm/damon: support pin-point targets removal" (SeongJae Park) Permit userspace to remove a specific monitoring target in the middle of the current targets list "mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo) A couple of cleanups related to mm header file inclusion "mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He) improve the selection of swap devices for NUMA machines "mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista) Change the memory block labels from macros to enums so they will appear in kernel debug info "ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes) Address an inefficiency when KSM unmerges an address range "mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park) Fix leaks and unhandled malloc() failures in DAMON userspace unit tests "some cleanups for pageout()" (Baolin Wang) Clean up a couple of minor things in the page scanner's writeback-for-eviction code "mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu) Move hugetlb's sysfs/sysctl handling code into a new file "introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes) Make the VMA guard regions available in /proc/pid/smaps and improves the mergeability of guarded VMAs "mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes) Reduce mmap lock contention for callers performing VMA guard region operations "vma_start_write_killable" (Matthew Wilcox) Start work on permitting applications to be killed when they are waiting on a read_lock on the VMA lock "mm/damon/tests: add more tests for online parameters commit" (SeongJae Park) Add additional userspace testing of DAMON's "commit" feature "mm/damon: misc cleanups" (SeongJae Park) "make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes) Address the possible loss of a VMA's VM_SOFTDIRTY flag when that VMA is merged with another "mm: support device-private THP" (Balbir Singh) Introduce support for Transparent Huge Page (THP) migration in zone device-private memory "Optimize folio split in memory failure" (Zi Yan) "mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang) Some more cleanups in the folio splitting code "mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes) Clean up our handling of pagetable leaf entries by introducing the concept of 'software leaf entries', of type softleaf_t "reparent the THP split queue" (Muchun Song) Reparent the THP split queue to its parent memcg. This is in preparation for addressing the long-standing "dying memcg" problem, wherein dead memcg's linger for too long, consuming memory resources "unify PMD scan results and remove redundant cleanup" (Wei Yang) A little cleanup in the hugepage collapse code "zram: introduce writeback bio batching" (Sergey Senozhatsky) Improve zram writeback efficiency by introducing batched bio writeback support "memcg: cleanup the memcg stats interfaces" (Shakeel Butt) Clean up our handling of the interrupt safety of some memcg stats "make vmalloc gfp flags usage more apparent" (Vishal Moola) Clean up vmalloc's handling of incoming GFP flags "mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang) Teach soft dirty and userfaultfd write protect tracking to use RISC-V's Svrsw60t59b extension "mm: swap: small fixes and comment cleanups" (Youngjun Park) Fix a small bug and clean up some of the swap code "initial work on making VMA flags a bitmap" (Lorenzo Stoakes) Start work on converting the vma struct's flags to a bitmap, so we stop running out of them, especially on 32-bit "mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park) Address a possible bug in the swap discard code and clean things up a little [ This merge also reverts commit ebb9aeb980e5 ("vfio/nvgrace-gpu: register device memory for poison handling") because it looks broken to me, I've asked for clarification - Linus ] * tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm: fix vma_start_write_killable() signal handling mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate mm/swapfile: fix list iteration when next node is removed during discard fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling mm/kfence: add reboot notifier to disable KFENCE on shutdown memcg: remove inc/dec_lruvec_kmem_state helpers selftests/mm/uffd: initialize char variable to Null mm: fix DEBUG_RODATA_TEST indentation in Kconfig mm: introduce VMA flags bitmap type tools/testing/vma: eliminate dependency on vma->__vm_flags mm: simplify and rename mm flags function for clarity mm: declare VMA flags by bit zram: fix a spelling mistake mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity mm/vmscan: skip increasing kswapd_failures when reclaim was boosted pagemap: update BUDDY flag documentation mm: swap: remove scan_swap_map_slots() references from comments mm: swap: change swap_alloc_slow() to void mm, swap: remove redundant comment for read_swap_cache_async mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational ...
2025-12-02Merge tag 'x86_cache_for_v6.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 resource control updates from Borislav Petkov: - Add support for AMD's Smart Data Cache Injection feature which allows for direct insertion of data from I/O devices into the L3 cache, thus bypassing DRAM and saving its bandwidth; the resctrl side of the feature allows the size of the L3 used for data injection to be controlled - Add Intel Clearwater Forest to the list of CPUs which support Sub-NUMA clustering - Other fixes and cleanups * tag 'x86_cache_for_v6.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fs/resctrl: Update bit_usage to reflect io_alloc fs/resctrl: Introduce interface to modify io_alloc capacity bitmasks fs/resctrl: Modify struct rdt_parse_data to pass mode and CLOSID fs/resctrl: Introduce interface to display io_alloc CBMs fs/resctrl: Add user interface to enable/disable io_alloc feature fs/resctrl: Introduce interface to display "io_alloc" support x86,fs/resctrl: Implement "io_alloc" enable/disable handlers x86,fs/resctrl: Detect io_alloc feature x86/resctrl: Add SDCIAE feature in the command line options x86/cpufeatures: Add support for L3 Smart Data Cache Injection Allocation Enforcement fs/resctrl: Consider sparse masks when initializing new group's allocation x86/resctrl: Support Sub-NUMA Cluster (SNC) mode on Clearwater Forest
2025-11-22fs/resctrl: Update bit_usage to reflect io_allocBabu Moger
The "shareable_bits" and "bit_usage" resctrl files associated with cache resources give insight into how instances of a cache is used. Update the annotated capacity bitmasks displayed by "bit_usage" to include the cache portions allocated for I/O via the "io_alloc" feature. "shareable_bits" is a global bitmask of shareable cache with I/O and can thus not present the per-domain I/O allocations possible with the "io_alloc" feature. Revise the "shareable_bits" documentation to direct users to "bit_usage" for accurate cache usage information. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/e02a0d424129fd7f3e45822a559b1c614ae4652a.1762995456.git.babu.moger@amd.com
2025-11-22fs/resctrl: Introduce interface to modify io_alloc capacity bitmasksBabu Moger
The io_alloc feature in resctrl enables system software to configure the portion of the cache allocated for I/O traffic. When supported, the io_alloc_cbm file in resctrl provides access to capacity bitmasks (CBMs) allocated for I/O devices. Enable users to modify io_alloc CBMs by writing to the io_alloc_cbm resctrl file when the io_alloc feature is enabled. Mirror the CBMs between CDP_CODE and CDP_DATA when CDP is enabled to present consistent I/O allocation information to user space. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/67609641b03ccfba18a8ee0bf9dbd1f3dcbecda3.1762995456.git.babu.moger@amd.com
2025-11-22fs/resctrl: Modify struct rdt_parse_data to pass mode and CLOSIDBabu Moger
parse_cbm() requires resource group mode and CLOSID to validate the capacity bitmask (CBM). It is passed via struct rdtgroup in struct rdt_parse_data. The io_alloc feature also uses CBMs to indicate which portions of cache are allocated for I/O traffic. The CBMs are provided by user space and need to be validated the same as CBMs provided for general (CPU) cache allocation. parse_cbm() cannot be used as-is since io_alloc does not have rdtgroup context. Pass the resource group mode and CLOSID directly to parse_cbm() via struct rdt_parse_data, instead of through the rdtgroup struct, to facilitate calling parse_cbm() to verify the CBM of the io_alloc feature. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/f8ec6ab5cf594d906a3fe75f56793d5fbd63f38f.1762995456.git.babu.moger@amd.com
2025-11-22fs/resctrl: Introduce interface to display io_alloc CBMsBabu Moger
Introduce the "io_alloc_cbm" resctrl file to display the capacity bitmasks (CBMs) that represent the portions of each cache instance allocated for I/O traffic on a cache resource that supports the "io_alloc" feature. io_alloc_cbm resides in the info directory of a cache resource, for example, /sys/fs/resctrl/info/L3/. Since the resource name is part of the path, it is not necessary to display the resource name as done in the schemata file. When CDP is enabled, io_alloc routes traffic using the highest CLOSID associated with the CDP_CODE resource and that CLOSID becomes unusable for the CDP_DATA resource. The highest CLOSID of CDP_CODE and CDP_DATA resources will be kept in sync to ensure consistent user interface. In preparation for this, access the CBMs for I/O traffic through highest CLOSID of either CDP_CODE or CDP_DATA resource. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/55a3ff66a70e7ce8239f022e62b334e9d64af604.1762995456.git.babu.moger@amd.com
2025-11-21fs/resctrl: Add user interface to enable/disable io_alloc featureBabu Moger
AMD's SDCIAE forces all SDCI lines to be placed into the L3 cache portions identified by the highest-supported L3_MASK_n register, where n is the maximum supported CLOSID. To support this, when io_alloc resctrl feature is enabled, reserve the highest CLOSID exclusively for I/O allocation traffic making it no longer available for general CPU cache allocation. Introduce user interface to enable/disable io_alloc feature and encourage users to enable io_alloc only when running workloads that can benefit from this functionality. On enable, initialize the io_alloc CLOSID with all usable CBMs across all the domains. Since CLOSIDs are managed by resctrl fs, it is least invasive to make "io_alloc is supported by maximum supported CLOSID" part of the initial resctrl fs support for io_alloc. Take care to minimally (only in error messages) expose this use of CLOSID for io_alloc to user space so that this is not required from other architectures that may support io_alloc differently in the future. When resctrl is mounted with "-o cdp" to enable code/data prioritization, there are two L3 resources that can support I/O allocation: L3CODE and L3DATA. From resctrl fs perspective the two resources share a CLOSID and the architecture's available CLOSID are halved to support this. The architecture's underlying CLOSID used by SDCIAE when CDP is enabled is the CLOSID associated with the CDP_CODE resource, but from resctrl's perspective there is only one CLOSID for both CDP_CODE and CDP_DATA. CDP_DATA is thus not usable for general (CPU) cache allocation nor I/O allocation. Keep the CDP_CODE and CDP_DATA I/O alloc status in sync to avoid any confusion to user space. That is, enabling io_alloc on CDP_CODE does so on CDP_DATA and vice-versa, and keep the I/O allocation CBMs of CDP_CODE and CDP_DATA in sync. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/c7d3037795e653e22b02d8fc73ca80d9b075031c.1762995456.git.babu.moger@amd.com
2025-11-21fs/resctrl: Introduce interface to display "io_alloc" supportBabu Moger
Introduce the "io_alloc" resctrl file to the "info" area of a cache resource, for example /sys/fs/resctrl/info/L3/io_alloc. "io_alloc" indicates support for the "io_alloc" feature that allows direct insertion of data from I/O devices into the cache. Restrict exposing support for "io_alloc" to the L3 resource that is the only resource where this feature can be backed by AMD's L3 Smart Data Cache Injection Allocation Enforcement (SDCIAE). With that, the "io_alloc" file is only visible to user space if the L3 resource supports "io_alloc". Doing so makes the file visible for all cache resources though, for example also L2 cache (if it supports cache allocation). As a consequence, add capability for file to report expected "enabled" and "disabled", as well as "not supported". Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/e8b116a8f424128b227734bb1d433c14af478d90.1762995456.git.babu.moger@amd.com
2025-11-18fs/resctrl: Consider sparse masks when initializing new group's allocationReinette Chatre
A new resource group is intended to be created with sane defaults. For a cache resource this means all cache portions the new group could possibly allocate into. This includes unused cache portions and shareable cache portions used by other groups and hardware. New resource group creation does not take sparse masks into account. After determining the bitmask reflecting the new group's possible allocations the bitmask is forced to be contiguous even if the system supports sparse masks. For example, a new group could by default allocate into a large portion of cache represented by 0xff0f, but it is instead created with a mask of 0xf. Do not force a contiguous allocation range if the system supports sparse masks. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/abbbb008bc09d982d715e79d3b885c10f92c64e0.1763426240.git.reinette.chatre@intel.com
2025-11-16mm: update resctl to use mmap_prepareLorenzo Stoakes
Make use of the ability to specify a remap action within mmap_prepare to update the resctl pseudo-lock to use mmap_prepare in favour of the deprecated mmap hook. Link: https://lkml.kernel.org/r/95b28b066f37ca25f56fa9460a9367f1a866f88b.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-20x86,fs/resctrl: Fix NULL pointer dereference with events force-disabled in ↵Babu Moger
mbm_event mode The following NULL pointer dereference is encountered on mount of resctrl fs after booting a system that supports assignable counters with the "rdt=!mbmtotal,!mbmlocal" kernel parameters: BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:mbm_cntr_get Call Trace: rdtgroup_assign_cntr_event rdtgroup_assign_cntrs rdt_get_tree Specifying the kernel parameter "rdt=!mbmtotal,!mbmlocal" effectively disables the legacy X86_FEATURE_CQM_MBM_TOTAL and X86_FEATURE_CQM_MBM_LOCAL features and the MBM events they represent. This results in the per-domain MBM event related data structures to not be allocated during early initialization. resctrl fs initialization follows by implicitly enabling both MBM total and local events on a system that supports assignable counters (mbm_event mode), but this enabling occurs after the per-domain data structures have been created. After booting, resctrl fs assumes that an enabled event can access all its state. This results in NULL pointer dereference when resctrl attempts to access the un-allocated structures of an enabled event. Remove the late MBM event enabling from resctrl fs. This leaves a problem where the X86_FEATURE_CQM_MBM_TOTAL and X86_FEATURE_CQM_MBM_LOCAL features may be disabled while assignable counter (mbm_event) mode is enabled without any events to support. Switching between the "default" and "mbm_event" mode without any events is not practical. Create a dependency between the X86_FEATURE_{CQM_MBM_TOTAL,CQM_MBM_LOCAL} and X86_FEATURE_ABMC (assignable counter) hardware features. An x86 system that supports assignable counters now requires support of X86_FEATURE_CQM_MBM_TOTAL or X86_FEATURE_CQM_MBM_LOCAL. This ensures all needed MBM related data structures are created before use and that it is only possible to switch between "default" and "mbm_event" mode when the same events are available in both modes. This dependency does not exist in the hardware but this usage of these feature settings work for known systems. [ bp: Massage commit message. ] Fixes: 13390861b426e ("x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details") Co-developed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/a62e6ac063d0693475615edd213d5be5e55443e6.1760560934.git.babu.moger@amd.com
2025-09-17fs/resctrl: Fix counter auto-assignment on mkdir with mbm_event enabledBabu Moger
rdt_resource::resctrl_mon::mbm_assign_on_mkdir determines if a counter will automatically be assigned to an RMID, MBM event pair when its associated monitor group is created via mkdir. Testing shows that counters are always automatically assigned to new monitor groups, whether mbm_assign_on_mkdir is set or not. To support automatic counter assignment the check for mbm_assign_on_mkdir should be in rdtgroup_assign_cntrs() that assigns counters during monitor group creation. Instead, the check for mbm_assign_on_mkdir is in rdtgroup_unassign_cntrs() that is called on monitor group deletion from where counters should always be unassigned, whether mbm_assign_on_mkdir is set or not. Fix automatic counter assignment by moving the mbm_assign_on_mkdir check from rdtgroup_unassign_cntrs() to rdtgroup_assign_cntrs(). [ bp: Replace commit message with Reinette's version. ] Fixes: ef712fe97ec57 ("fs/resctrl: Auto assign counters on mkdir and clean up on group removal") Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Reinette Chatre <reinette.chatre@intel.com>
2025-09-15fs/resctrl: Introduce the interface to switch between monitor modesBabu Moger
Resctrl subsystem can support two monitoring modes, "mbm_event" or "default". In mbm_event mode, monitoring event can only accumulate data while it is backed by a hardware counter. In "default" mode, resctrl assumes there is a hardware counter for each event within every CTRL_MON and MON group. Introduce mbm_assign_mode resctrl file to switch between mbm_event and default modes. Example: To list the MBM monitor modes supported: $ cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode [mbm_event] default To enable the "mbm_event" counter assignment mode: $ echo "mbm_event" > /sys/fs/resctrl/info/L3_MON/mbm_assign_mode To enable the "default" monitoring mode: $ echo "default" > /sys/fs/resctrl/info/L3_MON/mbm_assign_mode Reset MBM event counters automatically as part of changing the mode. Clear both architectural and non-architectural event states to prevent overflow conditions during the next event read. Clear assignable counter configuration on all the domains. Also, enable auto assignment when switching to "mbm_event" mode. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
2025-09-15fs/resctrl: Disable BMEC event configuration when mbm_event mode is enabledBabu Moger
The BMEC (Bandwidth Monitoring Event Configuration) feature enables per-domain event configuration. With BMEC the MBM events are configured using the mbm_total_bytes_config or mbm_local_bytes_config files in /sys/fs/resctrl/info/L3_MON/ and the per-domain event configuration affects all monitor resource groups. The mbm_event counter assignment mode enables counters to be assigned to RMID (i.e. a monitor resource group), event pairs, with potentially unique event configurations associated with every counter. There may be systems that support both BMEC and mbm_event counter assignment mode, but resctrl supporting both concurrently will present a conflicting interface to the user with both per-domain and per RMID, event configurations active at the same time. The mbm_event counter assignment provides most flexibility to user space and aligns with Arm's counter support. On systems that support both, disable BMEC event configuration when mbm_event mode is enabled by hiding the mbm_total_bytes_config or mbm_local_bytes_config files when mbm_event mode is enabled. Ensure mon_features always displays accurate information about monitor features. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
2025-09-15fs/resctrl: Introduce the interface to modify assignments in a groupBabu Moger
Enable the mbm_l3_assignments resctrl file to be used to modify counter assignments of CTRL_MON and MON groups when the "mbm_event" counter assignment mode is enabled. Process the assignment modifications in the following format: <Event>:<Domain id>=<Assignment state>;<Domain id>=<Assignment state> Event: A valid MBM event in the /sys/fs/resctrl/info/L3_MON/event_configs directory. Domain ID: A valid domain ID. When writing, '*' applies the changes to all domains. Assignment states: _ : Unassign a counter. e : Assign a counter exclusively. Examples: $ cd /sys/fs/resctrl $ cat /sys/fs/resctrl/mbm_L3_assignments mbm_total_bytes:0=e;1=e mbm_local_bytes:0=e;1=e To unassign the counter associated with the mbm_total_bytes event on domain 0: $ echo "mbm_total_bytes:0=_" > mbm_L3_assignments $ cat /sys/fs/resctrl/mbm_L3_assignments mbm_total_bytes:0=_;1=e mbm_local_bytes:0=e;1=e To unassign the counter associated with the mbm_total_bytes event on all the domains: $ echo "mbm_total_bytes:*=_" > mbm_L3_assignments $ cat /sys/fs/resctrl/mbm_L3_assignments mbm_total_bytes:0=_;1=_ mbm_local_bytes:0=e;1=e Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
2025-09-15fs/resctrl: Introduce mbm_L3_assignments to list assignments in a groupBabu Moger
Introduce the mbm_L3_assignments resctrl file associated with CTRL_MON and MON resource groups to display the counter assignment states of the resource group when "mbm_event" counter assignment mode is enabled. Display the list in the following format: <Event>:<Domain id>=<Assignment state>;<Domain id>=<Assignment state> Event: A valid MBM event listed in /sys/fs/resctrl/info/L3_MON/event_configs directory. Domain ID: A valid domain ID. The assignment state can be one of the following: _ : No counter assigned. e : Counter assigned exclusively. Example: To list the assignment states for the default group $ cd /sys/fs/resctrl $ cat /sys/fs/resctrl/mbm_L3_assignments mbm_total_bytes:0=e;1=e mbm_local_bytes:0=e;1=e Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
2025-09-15fs/resctrl: Auto assign counters on mkdir and clean up on group removalBabu Moger
Resctrl provides a user-configurable option mbm_assign_on_mkdir that determines if a counter will automatically be assigned to an RMID, event pair when its associated monitor group is created via mkdir. Enable mbm_assign_on_mkdir by default to automatically assign counters to the two default events (MBM total and MBM local) of a new monitoring group created via mkdir. This maintains backward compatibility with original resctrl support for these two events. Unassign and free counters belonging to a monitoring group when the group is deleted. Monitor group creation does not fail if a counter cannot be assigned to one or both events. There may be limited counters and users have the flexibility to modify counter assignments at a later time. Log the error message "Failed to allocate counter for <event> in domain <id>" in /sys/fs/resctrl/info/last_cmd_status when a new monitoring group is created but counter assignment failed. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com