kernel/linux.git/arch/mips/include/asm/page.h, branch linux-7.0.y

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

vdso: Introduce vdso/page.h

2024-10-15T22:13:04+00:00

The VDSO implementation includes headers from outside of the vdso/ namespace. Introduce vdso/page.h to make sure that the generic library uses only the allowed namespace. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Acked-by: Geert Uytterhoeven # m68k Link: https://lore.kernel.org/all/20241014151340.1639555-3-vincenzo.frascino@arm.com

arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitions

2024-03-06T18:28:26+00:00

These four architectures define the same Kconfig symbols for configuring the page size. Move the logic into a common place where it can be shared with all other architectures. Reviewed-by: Thomas Gleixner Signed-off-by: Arnd Bergmann

MIPS: Fix typos

2024-01-08T09:39:12+00:00

Fix typos, most reported by "codespell arch/mips". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas Cc: linux-mips@vger.kernel.org Reviewed-by: Randy Dunlap Signed-off-by: Thomas Bogendoerfer

mm, arch: add generic implementation of pfn_valid() for FLATMEM

2023-02-10T00:51:41+00:00

Every architecture that supports FLATMEM memory model defines its own version of pfn_valid() that essentially compares a pfn to max_mapnr. Use mips/powerpc version implemented as static inline as a generic implementation of pfn_valid() and drop its per-architecture definitions. [rppt@kernel.org: fix the generic pfn_valid()] Link: https://lkml.kernel.org/r/Y9lg7R1Yd931C+y5@kernel.org Link: https://lkml.kernel.org/r/20230129124235.209895-5-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) Acked-by: Arnd Bergmann Acked-by: Guo Ren [csky] Acked-by: Huacai Chen [LoongArch] Acked-by: Stafford Horne [OpenRISC] Acked-by: Michael Ellerman [powerpc] Reviewed-by: David Hildenbrand Tested-by: Conor Dooley Cc: Brian Cain Cc: "David S. Miller" Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: Helge Deller Cc: Huacai Chen Cc: Matt Turner Cc: Max Filippov Cc: Michal Simek Cc: Palmer Dabbelt Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Thomas Bogendoerfer Cc: Vineet Gupta Cc: WANG Xuerui Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mips: drop definition of pfn_valid() for DISCONTIGMEM

2023-02-10T00:51:41+00:00

There is a stale definition of pfn_valid() for DISCONTINGMEM memory model guarded !FLATMEM && !SPARSEMEM && NUMA ifdefery. Remove everything but definition of pfn_valid() for FLATMEM. Link: https://lkml.kernel.org/r/20230129124235.209895-4-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) Reviewed-by: David Hildenbrand Cc: Arnd Bergmann Cc: Brian Cain Cc: "David S. Miller" Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: Guo Ren Cc: Helge Deller Cc: Huacai Chen Cc: Huacai Chen Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Vineet Gupta Cc: WANG Xuerui Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA

2021-06-29T17:53:55+00:00

After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA configuration options are equivalent. Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead. Done with $ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \ $(git grep -wl CONFIG_NEED_MULTIPLE_NODES) $ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \ $(git grep -wl NEED_MULTIPLE_NODES) with manual tweaks afterwards. [rppt@linux.ibm.com: fix arm boot crash] Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org Signed-off-by: Mike Rapoport Acked-by: Arnd Bergmann Acked-by: David Hildenbrand Cc: Geert Uytterhoeven Cc: Ivan Kokshaysky Cc: Jonathan Corbet Cc: Matt Turner Cc: Richard Henderson Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

MIPS: Add support for CONFIG_DEBUG_VIRTUAL

2021-04-06T12:34:02+00:00

Provide hooks to intercept bad usages of virt_to_phys() and __pa_symbol() throughout the kernel. To make this possible, we need to rename the current implement of virt_to_phys() into __virt_to_phys_nodebug() and wrap it around depending on CONFIG_DEBUG_VIRTUAL. A similar thing is needed for __pa_symbol() which is now aliased to __phys_addr_symbol() whose implementation is either the direct return of RELOC_HIDE or goes through the debug version. Signed-off-by: Florian Fainelli Signed-off-by: Thomas Bogendoerfer

mips: Replace lkml.org links with lore

2021-02-11T10:00:29+00:00

As started by commit 05a5f51ca566 ("Documentation: Replace lkml.org links with lore"), replace lkml.org links with lore to better use a single source that's more likely to stay available long-term. Signed-off-by: Kees Cook Signed-off-by: Thomas Bogendoerfer

MIPS: relocatable: Provide kaslr_offset() to get the kernel offset

2021-02-09T09:54:29+00:00

Provide kaslr_offset() to get the kernel offset when KASLR is enabled. Error may occur before update_kaslr_offset(), so put it at the end of the offset branch. Fixes: a307a4ce9ecd ("MIPS: Loongson64: Add KASLR support") Reported-by: kernel test robot Signed-off-by: Jinyang He Signed-off-by: Thomas Bogendoerfer