kernel/linux.git/arch/microblaze/include, branch v7.0-rc7

treewide: provide a generic clear_user_page() variant

2026-01-21T03:24:39+00:00

Patch series "mm: folio_zero_user: clear page ranges", v11. This series adds clearing of contiguous page ranges for hugepages. The series improves on the current discontiguous clearing approach in two ways: - clear pages in a contiguous fashion. - use batched clearing via clear_pages() wherever exposed. The first is useful because it allows us to make much better use of hardware prefetchers. The second, enables advertising the real extent to the processor. Where specific instructions support it (ex. string instructions on x86; "mops" on arm64 etc), a processor can optimize based on this because, instead of seeing a sequence of 8-byte stores, or a sequence of 4KB pages, it sees a larger unit being operated on. For instance, AMD Zen uarchs (for extents larger than LLC-size) switch to a mode where they start eliding cacheline allocation. This is helpful not just because it results in higher bandwidth, but also because now the cache is not evicting useful cachelines and replacing them with zeroes. Demand faulting a 64GB region shows performance improvement: $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5 baseline +series (GBps +- %stdev) (GBps +- %stdev) pg-sz=2MB 11.76 +- 1.10% 25.34 +- 1.18% [*] +115.47% preempt=* pg-sz=1GB 24.85 +- 2.41% 39.22 +- 2.32% + 57.82% preempt=none|voluntary pg-sz=1GB (similar) 52.73 +- 0.20% [#] +112.19% preempt=full|lazy [*] This improvement is because switching to sequential clearing allows the hardware prefetchers to do a much better job. [#] For pg-sz=1GB a large part of the improvement is because of the cacheline elision mentioned above. preempt=full|lazy improves upon that because, not needing explicit invocations of cond_resched() to ensure reasonable preemption latency, it can clear the full extent as a single unit. In comparison the maximum extent used for preempt=none|voluntary is PROCESS_PAGES_NON_PREEMPT_BATCH (32MB). When provided the full extent the processor forgoes allocating cachelines on this path almost entirely. (The hope is that eventually, in the fullness of time, the lazy preemption model will be able to do the same job that none or voluntary models are used for, allowing us to do away with cond_resched().) Raghavendra also tested previous version of the series on AMD Genoa and sees similar improvement [1] with preempt=lazy. $ perf bench mem map -p $page-size -f populate -s 64GB -l 10 base patched change pg-sz=2MB 12.731939 GB/sec 26.304263 GB/sec 106.6% pg-sz=1GB 26.232423 GB/sec 61.174836 GB/sec 133.2% This patch (of 8): Let's drop all variants that effectively map to clear_page() and provide it in a generic variant instead. We'll use the macro clear_user_page to indicate whether an architecture provides it's own variant. Also, clear_user_page() is only called from the generic variant of clear_user_highpage(), so define it only if the architecture does not provide a clear_user_highpage(). And, for simplicity define it in linux/highmem.h. Note that for parisc, clear_page() and clear_user_page() map to clear_page_asm(), so we can just get rid of the custom clear_user_page() implementation. There is a clear_user_page_asm() function on parisc, that seems to be unused. Not sure what's up with that. Link: https://lkml.kernel.org/r/20260107072009.1615991-1-ankur.a.arora@oracle.com Link: https://lkml.kernel.org/r/20260107072009.1615991-2-ankur.a.arora@oracle.com Signed-off-by: David Hildenbrand Co-developed-by: Ankur Arora Signed-off-by: Ankur Arora Cc: Andy Lutomirski Cc: Ankur Arora Cc: "Borislav Petkov (AMD)" Cc: Boris Ostrovsky Cc: David Hildenbrand Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Konrad Rzessutek Wilk Cc: Lance Yang Cc: "Liam R. Howlett" Cc: Li Zhe Cc: Lorenzo Stoakes Cc: Mateusz Guzik Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Suren Baghdasaryan Cc: Thomas Gleixner Cc: Vlastimil Babka Signed-off-by: Andrew Morton

Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2025-10-03T18:37:50+00:00

Pull misc non-vfs updates from Al Viro: "Assorted dead code removal around asm/pgtable.h" * tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: alpha: unobfuscate _PAGE_P() definition kill FIRST_USER_PGD_NR alpha: get rid of the remnants of BAD_PAGE and friends SET_PAGE_DIR() users had been gone since 2.3.12pre1 PAGE_PTR() had been last used outside of arch/* in 1.1.94 csky: remove BS check for FAULT_FLAG_ALLOW_RETRY

kill FIRST_USER_PGD_NR

2025-09-16T01:11:39+00:00

dead since 2005, time to bury the body... Reviewed-by: Michal Simek # microblaze Reviewed-by: Max Filippov Signed-off-by: Al Viro

microblaze: Replace ASSEMBLY with ASSEMBLER in non-uapi headers

2025-09-12T11:12:42+00:00

While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembly code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This can be very confusing when switching between userspace and kernelspace coding, or when dealing with uapi headers that rather should use __ASSEMBLER__ instead. So let's standardize on the __ASSEMBLER__ macro that is provided by the compilers now. This is a completely mechanical patch (done with a simple "sed -i" statement). Cc: Michal Simek Signed-off-by: Thomas Huth Link: https://lore.kernel.org/r/20250314071013.1575167-19-thuth@redhat.com Signed-off-by: Michal Simek

microblaze: Replace ASSEMBLY with ASSEMBLER in uapi headers

2025-09-12T11:12:41+00:00

__ASSEMBLY__ is only defined by the Makefile of the kernel, so this is not really useful for uapi headers (unless the userspace Makefile defines it, too). Let's switch to __ASSEMBLER__ which gets set automatically by the compiler when compiling assembly code. This is a completely mechanical patch (done with a simple "sed -i" statement). Cc: Michal Simek Signed-off-by: Thomas Huth Link: https://lore.kernel.org/r/20250314071013.1575167-18-thuth@redhat.com Signed-off-by: Michal Simek

mm: pgtable: fix pte_swp_exclusive

2025-06-11T21:52:08+00:00

Make pte_swp_exclusive return bool instead of int. This will better reflect how pte_swp_exclusive is actually used in the code. This fixes swap/swapoff problems on Alpha due pte_swp_exclusive not returning correct values when _PAGE_SWP_EXCLUSIVE bit resides in upper 32-bits of PTE (like on alpha). Suggested-by: Al Viro Signed-off-by: Magnus Lindholm Cc: Sam James Link: https://lore.kernel.org/lkml/20250218175735.19882-2-linmag7@gmail.com/ Link: https://lore.kernel.org/lkml/20250602041118.GA2675383@ZenIV/ [ Applied as the 'sed' script Al suggested - Linus ] Signed-off-by: Linus Torvalds

syscall.h: introduce syscall_set_nr()

2025-05-12T00:48:15+00:00

Similar to syscall_set_arguments() that complements syscall_get_arguments(), introduce syscall_set_nr() that complements syscall_get_nr(). syscall_set_nr() is going to be needed along with syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io Signed-off-by: Dmitry V. Levin Tested-by: Charlie Jenkins Reviewed-by: Charlie Jenkins Acked-by: Helge Deller # parisc Reviewed-by: Maciej W. Rozycki # mips Cc: Alexander Gordeev Cc: Alexey Gladkov (Intel) Cc: Andreas Larsson Cc: anton ivanov Cc: Arnd Bergmann Cc: Borislav Betkov Cc: Brian Cain Cc: Christian Borntraeger Cc: Christian Zankel Cc: Christophe Leroy Cc: Dave Hansen Cc: Davide Berardi Cc: David S. Miller Cc: Dinh Nguyen Cc: Eugene Syromiatnikov Cc: Eugene Syromyatnikov Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Jonas Bonn Cc: Madhavan Srinivasan Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Frysinger Cc: Naveen N Rao Cc: Nicholas Piggin Cc: Oleg Nesterov Cc: Renzo Davoi Cc: Richard Weinberger Cc: Rich Felker Cc: Russel King Cc: Shuah Khan Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mm: introduce a common definition of mk_pte()

2025-05-12T00:48:02+00:00

Most architectures simply call pfn_pte(). Centralise that as the normal definition and remove the definition of mk_pte() from the architectures which have either that exact definition or something similar. Link: https://lkml.kernel.org/r/20250402181709.2386022-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Geert Uytterhoeven # m68k Acked-by: David Hildenbrand Reviewed-by: Alexander Gordeev # s390 Cc: Zi Yan Cc: Andreas Larsson Cc: Anton Ivanov Cc: Dave Hansen Cc: "David S. Miller" Cc: Johannes Berg Cc: Muchun Song Cc: Richard Weinberger Cc: Signed-off-by: Andrew Morton

asm-generic: pgalloc: provide generic __pgd_{alloc,free}

2025-01-26T04:22:24+00:00

We already have a generic implementation of alloc/free up to P4D level, as well as pgd_free(). Let's finish the work and add a generic PGD-level alloc helper as well. Unlike at lower levels, almost all architectures need some specific magic at PGD level (typically initialising PGD entries), so introducing a generic pgd_alloc() isn't worth it. Instead we introduce two new helpers, __pgd_alloc() and __pgd_free(), and make use of them in the arch-specific pgd_alloc() and pgd_free() wherever possible. To accommodate as many arch as possible, __pgd_alloc() takes a page allocation order. Because pagetable_alloc() allocates zeroed pages, explicit zeroing in pgd_alloc() becomes redundant and we can get rid of it. Some trivial implementations of pgd_free() also become unnecessary once __pgd_alloc() is used; remove them. Another small improvement is consistent accounting of PGD pages by using GFP_PGTABLE_{USER,KERNEL} as appropriate. Not all PGD allocations can be handled by the generic helpers. In particular, multiple architectures allocate PGDs from a kmem_cache, and those PGDs may not be page-sized. Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Acked-by: Dave Hansen Acked-by: Qi Zheng Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Ingo Molnar Cc: Linus Walleij Cc: Matthew Wilcox (Oracle) Cc: Mike Rapoport (Microsoft) Cc: Peter Zijlstra Cc: Ryan Roberts Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-23T17:58:07+00:00

Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...