user/sven/linux.git/include/linux/pgtable.h, branch v6.17.6

include/linux/pgtable.h: convert arch_enter_lazy_mmu_mode() and friends to static inlines

2025-09-25T23:10:35Z

commit c519c3c0a113 ("mm/kasan: avoid lazy MMU mode hazards") introduced the use of arch_enter_lazy_mmu_mode(), which results in the compiler complaining about "statement has no effect", when __HAVE_ARCH_LAZY_MMU_MODE is not defined in include/linux/pgtable.h The exact warning/error is: In file included from ./include/linux/kasan.h:37, from mm/kasan/shadow.c:14: mm/kasan/shadow.c: In function kasan_populate_vmalloc_pte: ./include/linux/pgtable.h:247:41: error: statement with no effect [-Werror=unused-value] 247 | #define arch_enter_lazy_mmu_mode() (LAZY_MMU_DEFAULT) | ^ mm/kasan/shadow.c:322:9: note: in expansion of macro arch_enter_lazy_mmu_mode> 322 | arch_enter_lazy_mmu_mode(); | ^~~~~~~~~~~~~~~~~~~~~~~~ switching these "functions" to static inlines fixes this up. Fixes: c519c3c0a113 ("mm/kasan: avoid lazy MMU mode hazards") Reported-by: Balbir Singh Closes: https://lkml.kernel.org/r/20250912235515.367061-1-balbirs@nvidia.com Cc: Alexander Gordeev Cc: Andrey Ryabinin Signed-off-by: Andrew Morton

mm: introduce and use {pgd,p4d}_populate_kernel()

2025-08-28T05:45:44Z

Introduce and use {pgd,p4d}_populate_kernel() in core MM code when populating PGD and P4D entries for the kernel address space. These helpers ensure proper synchronization of page tables when updating the kernel portion of top-level page tables. Until now, the kernel has relied on each architecture to handle synchronization of top-level page tables in an ad-hoc manner. For example, see commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes"). However, this approach has proven fragile for following reasons: 1) It is easy to forget to perform the necessary page table synchronization when introducing new changes. For instance, commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") overlooked the need to synchronize page tables for the vmemmap area. 2) It is also easy to overlook that the vmemmap and direct mapping areas must not be accessed before explicit page table synchronization. For example, commit 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges")) caused crashes by accessing the vmemmap area before calling sync_global_pgds(). To address this, as suggested by Dave Hansen, introduce _kernel() variants of the page table population helpers, which invoke architecture-specific hooks to properly synchronize page tables. These are introduced in a new header file, include/linux/pgalloc.h, so they can be called from common code. They reuse existing infrastructure for vmalloc and ioremap. Synchronization requirements are determined by ARCH_PAGE_TABLE_SYNC_MASK, and the actual synchronization is performed by arch_sync_kernel_mappings(). This change currently targets only x86_64, so only PGD and P4D level helpers are introduced. Currently, these helpers are no-ops since no architecture sets PGTBL_{PGD,P4D}_MODIFIED in ARCH_PAGE_TABLE_SYNC_MASK. In theory, PUD and PMD level helpers can be added later if needed by other architectures. For now, 32-bit architectures (x86-32 and arm) only handle PGTBL_PMD_MODIFIED, so p*d_populate_kernel() will never affect them unless we introduce a PMD level helper. [harry.yoo@oracle.com: fix KASAN build error due to p*d_populate_kernel()] Link: https://lkml.kernel.org/r/20250822020727.202749-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-3-harry.yoo@oracle.com Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo Suggested-by: Dave Hansen Acked-by: Kiryl Shutsemau Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Cc: Alexander Potapenko Cc: Alistair Popple Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: "Aneesh Kumar K.V" Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: bibo mao Cc: Borislav Betkov Cc: Christoph Lameter (Ampere) Cc: Dennis Zhou Cc: Dev Jain Cc: Dmitriy Vyukov Cc: Gwan-gyeong Mun Cc: Ingo Molnar Cc: Jane Chu Cc: Joao Martins Cc: Joerg Roedel Cc: John Hubbard Cc: Kevin Brodsky Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Tejun Heo Cc: Thomas Gleinxer Cc: Thomas Huth Cc: "Uladzislau Rezki (Sony)" Cc: Vincenzo Frascino Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

mm: move page table sync declarations to linux/pgtable.h

2025-08-28T05:45:44Z

During our internal testing, we started observing intermittent boot failures when the machine uses 4-level paging and has a large amount of persistent memory: BUG: unable to handle page fault for address: ffffe70000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI RIP: 0010:__init_single_page+0x9/0x6d Call Trace: __init_zone_device_page+0x17/0x5d memmap_init_zone_device+0x154/0x1bb pagemap_range+0x2e0/0x40f memremap_pages+0x10b/0x2f0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0xce/0x2ec [device_dax] dax_bus_probe+0x6d/0xc9 [... snip ...] It turns out that the kernel panics while initializing vmemmap (struct page array) when the vmemmap region spans two PGD entries, because the new PGD entry is only installed in init_mm.pgd, but not in the page tables of other tasks. And looking at __populate_section_memmap(): if (vmemmap_can_optimize(altmap, pgmap)) // does not sync top level page tables r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap); else // sync top level page tables in x86 r = vmemmap_populate(start, end, nid, altmap); In the normal path, vmemmap_populate() in arch/x86/mm/init_64.c synchronizes the top level page table (See commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes")) so that all tasks in the system can see the new vmemmap area. However, when vmemmap_can_optimize() returns true, the optimized path skips synchronization of top-level page tables. This is because vmemmap_populate_compound_pages() is implemented in core MM code, which does not handle synchronization of the top-level page tables. Instead, the core MM has historically relied on each architecture to perform this synchronization manually. We're not the first party to encounter a crash caused by not-sync'd top level page tables: earlier this year, Gwan-gyeong Mun attempted to address the issue [1] [2] after hitting a kernel panic when x86 code accessed the vmemmap area before the corresponding top-level entries were synced. At that time, the issue was believed to be triggered only when struct page was enlarged for debugging purposes, and the patch did not get further updates. It turns out that current approach of relying on each arch to handle the page table sync manually is fragile because 1) it's easy to forget to sync the top level page table, and 2) it's also easy to overlook that the kernel should not access the vmemmap and direct mapping areas before the sync. # The solution: Make page table sync more code robust and harder to miss To address this, Dave Hansen suggested [3] [4] introducing {pgd,p4d}_populate_kernel() for updating kernel portion of the page tables and allow each architecture to explicitly perform synchronization when installing top-level entries. With this approach, we no longer need to worry about missing the sync step, reducing the risk of future regressions. The new interface reuses existing ARCH_PAGE_TABLE_SYNC_MASK, PGTBL_P*D_MODIFIED and arch_sync_kernel_mappings() facility used by vmalloc and ioremap to synchronize page tables. pgd_populate_kernel() looks like this: static inline void pgd_populate_kernel(unsigned long addr, pgd_t *pgd, p4d_t *p4d) { pgd_populate(&init_mm, pgd, p4d); if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED) arch_sync_kernel_mappings(addr, addr); } It is worth noting that vmalloc() and apply_to_range() carefully synchronizes page tables by calling p*d_alloc_track() and arch_sync_kernel_mappings(), and thus they are not affected by this patch series. This series was hugely inspired by Dave Hansen's suggestion and hence added Suggested-by: Dave Hansen. Cc stable because lack of this series opens the door to intermittent boot failures. This patch (of 3): Move ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to linux/pgtable.h so that they can be used outside of vmalloc and ioremap. Link: https://lkml.kernel.org/r/20250818020206.4517-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-2-harry.yoo@oracle.com Link: https://lore.kernel.org/linux-mm/20250220064105.808339-1-gwan-gyeong.mun@intel.com [1] Link: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@intel.com [2] Link: https://lore.kernel.org/linux-mm/d1da214c-53d3-45ac-a8b6-51821c5416e4@intel.com [3] Link: https://lore.kernel.org/linux-mm/4d800744-7b88-41aa-9979-b245e8bf794b@intel.com [4] Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo Acked-by: Kiryl Shutsemau Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: "Uladzislau Rezki (Sony)" Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Cc: Alexander Potapenko Cc: Alistair Popple Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: "Aneesh Kumar K.V" Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: bibo mao Cc: Borislav Betkov Cc: Christoph Lameter (Ampere) Cc: Dennis Zhou Cc: Dev Jain Cc: Dmitriy Vyukov Cc: Gwan-gyeong Mun Cc: Ingo Molnar Cc: Jane Chu Cc: Joao Martins Cc: Joerg Roedel Cc: John Hubbard Cc: Kevin Brodsky Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Tejun Heo Cc: Thomas Gleinxer Cc: Thomas Huth Cc: Vincenzo Frascino Cc: Vlastimil Babka Cc: Dave Hansen Cc: Signed-off-by: Andrew Morton

mm: add get_and_clear_ptes() and clear_ptes()

2025-08-02T19:06:10Z

Patch series "Optimizations for khugepaged", v4. If the underlying folio mapped by the ptes is large, we can process those ptes in a batch using folio_pte_batch(). For arm64 specifically, this results in a 16x reduction in the number of ptep_get() calls, since on a contig block, ptep_get() on arm64 will iterate through all 16 entries to collect a/d bits. Next, ptep_clear() will cause a TLBI for every contig block in the range via contpte_try_unfold(). Instead, use clear_ptes() to only do the TLBI at the first and last contig block of the range. For split folios, there will be no pte batching; the batch size returned by folio_pte_batch() will be 1. For pagetable split folios, the ptes will still point to the same large folio; for arm64, this results in the optimization described above, and for other arches, a minor improvement is expected due to a reduction in the number of function calls and batching atomic operations. This patch (of 3): Let's add variants to be used where "full" does not apply -- which will be the majority of cases in the future. "full" really only applies if we are about to tear down a full MM. Use get_and_clear_ptes() in existing code, clear_ptes() users will be added next. Link: https://lkml.kernel.org/r/20250724052301.23844-2-dev.jain@arm.com Signed-off-by: David Hildenbrand Signed-off-by: Dev Jain Reviewed-by: Baolin Wang Reviewed-by: Barry Song Reviewed-by: Lorenzo Stoakes Reviewed-by: Zi Yan Cc: Liam Howlett Cc: Mariano Pache Cc: Ryan Roberts Signed-off-by: Andrew Morton

mm: add batched versions of ptep_modify_prot_start/commit

2025-07-25T02:12:40Z

Batch ptep_modify_prot_start/commit in preparation for optimizing mprotect, implementing them as a simple loop over the corresponding single pte helpers. Architecture may override these helpers. Link: https://lkml.kernel.org/r/20250718090244.21092-4-dev.jain@arm.com Signed-off-by: Dev Jain Reviewed-by: Lorenzo Stoakes Reviewed-by: Barry Song Reviewed-by: Ryan Roberts Reviewed-by: Zi Yan Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Christophe Leroy Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jann Horn Cc: Joey Gouly Cc: Kevin Brodsky Cc: Lance Yang Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Vlastimil Babka Cc: Will Deacon Cc: Yang Shi Cc: Yicong Yang Cc: Zhenhua Huang Signed-off-by: Andrew Morton

mm: remove devmap related functions and page table bits

2025-07-10T05:42:18Z

Now that DAX and all other reference counts to ZONE_DEVICE pages are managed normally there is no need for the special devmap PTE/PMD/PUD page table bits. So drop all references to these, freeing up a software defined page table bit on architectures supporting it. Link: https://lkml.kernel.org/r/6389398c32cc9daa3dfcaa9f79c7972525d310ce.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple Acked-by: Will Deacon # arm64 Acked-by: David Hildenbrand Suggested-by: Chunyan Zhang Reviewed-by: Björn Töpel Reviewed-by: Jason Gunthorpe Cc: Balbir Singh Cc: Björn Töpel Cc: Christoph Hellwig Cc: Dan Williams Cc: Deepak Gupta Cc: Gerald Schaefer Cc: Inki Dae Cc: John Groves Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

mm: remove redundant pXd_devmap calls

2025-07-10T05:42:17Z

DAX was the only thing that created pmd_devmap and pud_devmap entries however it no longer does as DAX pages are now refcounted normally and pXd_trans_huge() returns true for those. Therefore checking both pXd_devmap and pXd_trans_huge() is redundant and the former can be removed without changing behaviour as it will always be false. Link: https://lkml.kernel.org/r/d58f089dc16b7feb7c6728164f37dea65d64a0d3.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple Cc: Balbir Singh Cc: Björn Töpel Cc: Björn Töpel Cc: Christoph Hellwig Cc: Chunyan Zhang Cc: Dan Williams Cc: David Hildenbrand Cc: Deepak Gupta Cc: Gerald Schaefer Cc: Inki Dae Cc: Jason Gunthorpe Cc: John Groves Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Will Deacon Signed-off-by: Andrew Morton

mm: change vm_get_page_prot() to accept vm_flags_t argument

2025-07-10T05:42:13Z

Patch series "use vm_flags_t consistently". The VMA flags field vma->vm_flags is of type vm_flags_t. Right now this is exactly equivalent to unsigned long, but it should not be assumed to be. Much code that references vma->vm_flags already correctly uses vm_flags_t, but a fairly large chunk of code simply uses unsigned long and assumes that the two are equivalent. This series corrects that and has us use vm_flags_t consistently. This series is motivated by the desire to, in a future series, adjust vm_flags_t to be a u64 regardless of whether the kernel is 32-bit or 64-bit in order to deal with the VMA flag exhaustion issue and avoid all the various problems that arise from it (being unable to use certain features in 32-bit, being unable to add new flags except for 64-bit, etc.) This is therefore a critical first step towards that goal. At any rate, using the correct type is of value regardless. We additionally take the opportunity to refer to VMA flags as vm_flags where possible to make clear what we're referring to. Overall, this series does not introduce any functional change. This patch (of 3): We abstract the type of the VMA flags to vm_flags_t, however in may places it is simply assumed this is unsigned long, which is simply incorrect. At the moment this is simply an incongruity, however in future we plan to change this type and therefore this change is a critical requirement for doing so. Overall, this patch does not introduce any functional change. [lorenzo.stoakes@oracle.com: add missing vm_get_page_prot() instance, remove include] Link: https://lkml.kernel.org/r/552f88e1-2df8-4e95-92b8-812f7c8db829@lucifer.local Link: https://lkml.kernel.org/r/cover.1750274467.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/a12769720a2743f235643b158c4f4f0a9911daf0.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: Mike Rapoport (Microsoft) Acked-by: Christian Brauner Reviewed-by: Vlastimil Babka Reviewed-by: Oscar Salvador Reviewed-by: Pedro Falcato Acked-by: Catalin Marinas [arm64] Acked-by: Zi Yan Acked-by: David Hildenbrand Reviewed-by: Anshuman Khandual Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Jann Horn Cc: Kees Cook Cc: Jan Kara Cc: Jarkko Sakkinen Signed-off-by: Andrew Morton

mm/filemap: allow arch to request folio size for exec memory

2025-07-10T05:42:03Z

Change the readahead config so that if it is being requested for an executable mapping, do a synchronous read into a set of folios with an arch-specified order and in a naturally aligned manner. We no longer center the read on the faulting page but simply align it down to the previous natural boundary. Additionally, we don't bother with an asynchronous part. On arm64 if memory is physically contiguous and naturally aligned to the "contpte" size, we can use contpte mappings, which improves utilization of the TLB. When paired with the "multi-size THP" feature, this works well to reduce dTLB pressure. However iTLB pressure is still high due to executable mappings having a low likelihood of being in the required folio size and mapping alignment, even when the filesystem supports readahead into large folios (e.g. XFS). The reason for the low likelihood is that the current readahead algorithm starts with an order-0 folio and increases the folio order by 2 every time the readahead mark is hit. But most executable memory tends to be accessed randomly and so the readahead mark is rarely hit and most executable folios remain order-0. So let's special-case the read(ahead) logic for executable mappings. The trade-off is performance improvement (due to more efficient storage of the translations in iTLB) vs potential for making reclaim more difficult (due to the folios being larger so if a part of the folio is hot the whole thing is considered hot). But executable memory is a small portion of the overall system memory so I doubt this will even register from a reclaim perspective. I've chosen 64K folio size for arm64 which benefits both the 4K and 16K base page size configs. Crucially the same amount of data is still read (usually 128K) so I'm not expecting any read amplification issues. I don't anticipate any write amplification because text is always RO. Note that the text region of an ELF file could be populated into the page cache for other reasons than taking a fault in a mmapped area. The most common case is due to the loader read()ing the header which can be shared with the beginning of text. So some text will still remain in small folios, but this simple, best effort change provides good performance improvements as is. Confine this special-case approach to the bounds of the VMA. This prevents wasting memory for any padding that might exist in the file between sections. Previously the padding would have been contained in order-0 folios and would be easy to reclaim. But now it would be part of a larger folio so more difficult to reclaim. Solve this by simply not reading it into memory in the first place. Benchmarking ============ The below shows pgbench and redis benchmarks on Graviton3 arm64 system. First, confirmation that this patch causes more text to be contained in 64K folios: +----------------------+---------------+---------------+---------------+ | File-backed folios by| system boot | pgbench | redis | | size as percentage of+-------+-------+-------+-------+-------+-------+ | all mapped text mem |before | after |before | after |before | after | +======================+=======+=======+=======+=======+=======+=======+ | base-page-4kB | 78% | 30% | 78% | 11% | 73% | 14% | | thp-aligned-8kB | 1% | 0% | 0% | 0% | 1% | 0% | | thp-aligned-16kB | 17% | 4% | 17% | 3% | 20% | 4% | | thp-aligned-32kB | 1% | 1% | 1% | 2% | 1% | 1% | | thp-aligned-64kB | 3% | 63% | 3% | 81% | 4% | 77% | | thp-aligned-128kB | 0% | 1% | 1% | 1% | 1% | 2% | | thp-unaligned-64kB | 0% | 0% | 0% | 1% | 0% | 1% | | thp-unaligned-128kB | 0% | 1% | 0% | 0% | 0% | 0% | | thp-partial | 0% | 0% | 0% | 1% | 0% | 1% | +----------------------+-------+-------+-------+-------+-------+-------+ | cont-aligned-64kB | 4% | 65% | 4% | 83% | 6% | 79% | +----------------------+-------+-------+-------+-------+-------+-------+ The above shows that for both workloads (each isolated with cgroups) as well as the general system state after boot, the amount of text backed by 4K and 16K folios reduces and the amount backed by 64K folios increases significantly. And the amount of text that is contpte-mapped significantly increases (see last row). And this is reflected in performance improvement. "(I)" indicates a statistically significant improvement. Note TPS and Reqs/sec are rates so bigger is better, ms is time so smaller is better: +-------------+-------------------------------------------+------------+ | Benchmark | Result Class | Improvemnt | +=============+===========================================+============+ | pts/pgbench | Scale: 1 Clients: 1 RO (TPS) | (I) 3.47% | | | Scale: 1 Clients: 1 RO - Latency (ms) | -2.88% | | | Scale: 1 Clients: 250 RO (TPS) | (I) 5.02% | | | Scale: 1 Clients: 250 RO - Latency (ms) | (I) -4.79% | | | Scale: 1 Clients: 1000 RO (TPS) | (I) 6.16% | | | Scale: 1 Clients: 1000 RO - Latency (ms) | (I) -5.82% | | | Scale: 100 Clients: 1 RO (TPS) | 2.51% | | | Scale: 100 Clients: 1 RO - Latency (ms) | -3.51% | | | Scale: 100 Clients: 250 RO (TPS) | (I) 4.75% | | | Scale: 100 Clients: 250 RO - Latency (ms) | (I) -4.44% | | | Scale: 100 Clients: 1000 RO (TPS) | (I) 6.34% | | | Scale: 100 Clients: 1000 RO - Latency (ms)| (I) -5.95% | +-------------+-------------------------------------------+------------+ | pts/redis | Test: GET Connections: 50 (Reqs/sec) | (I) 3.20% | | | Test: GET Connections: 1000 (Reqs/sec) | (I) 2.55% | | | Test: LPOP Connections: 50 (Reqs/sec) | (I) 4.59% | | | Test: LPOP Connections: 1000 (Reqs/sec) | (I) 4.81% | | | Test: LPUSH Connections: 50 (Reqs/sec) | (I) 5.31% | | | Test: LPUSH Connections: 1000 (Reqs/sec) | (I) 4.36% | | | Test: SADD Connections: 50 (Reqs/sec) | (I) 2.64% | | | Test: SADD Connections: 1000 (Reqs/sec) | (I) 4.15% | | | Test: SET Connections: 50 (Reqs/sec) | (I) 3.11% | | | Test: SET Connections: 1000 (Reqs/sec) | (I) 3.36% | +-------------+-------------------------------------------+------------+ [ryan.roberts@arm.com: fix use-after-free] Link: https://lkml.kernel.org/r/ea7f9da7-9a9f-4b85-9d0a-35b320f5ed25@arm.com [ryan.roberts@arm.com: use the vma_pages() helper instead of open-coding] Link: https://lkml.kernel.org/r/0e0f674b-3b7e-494f-ae7a-fc9dbb98dad4@arm.com Link: https://lkml.kernel.org/r/20250609092729.274960-6-ryan.roberts@arm.com Signed-off-by: Ryan Roberts Reviewed-by: Jan Kara Acked-by: Will Deacon Cc: Chaitanya S Prakash Cc: David Hildenbrand Signed-off-by: Andrew Morton

x86/mm/pat: remove old pfnmap tracking interface

2025-05-22T21:55:37Z

We can now get rid of the old interface along with get_pat_info() and follow_phys(). Link: https://lkml.kernel.org/r/20250512123424.637989-6-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Acked-by: Ingo Molnar [x86 bits] Reviewed-by: Liam R. Howlett Cc: Andy Lutomirski Cc: Borislav Betkov Cc: Dave Airlie Cc: "H. Peter Anvin" Cc: Jani Nikula Cc: Jann Horn Cc: Jonas Lahtinen Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Peter Xu Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Steven Rostedt Cc: Thomas Gleinxer Cc: Tvrtko Ursulin Cc: Vlastimil Babka Signed-off-by: Andrew Morton