- 06 May, 2024 10 commits
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David Hildenbrand authored
As we grow the code, the compiler might make stupid decisions and unnecessarily degrade fork() performance. Let's make sure to always inline functions that operate on a single PTE so the compiler will always optimize out the loop and avoid a function call. This is a preparation for maintining a total mapcount for large folios. Link: https://lkml.kernel.org/r/20240409192301.907377-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Cc: Chris Zankel <chris@zankel.net> Cc: Hugh Dickins <hughd@google.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Richard Chang <richardycc@google.com> Cc: Rich Felker <dalias@libc.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Patch series "mm: mapcount for large folios + page_mapcount() cleanups". This series tracks the mapcount of large folios in a single value, so it can be read efficiently and atomically, just like the mapcount of small folios. folio_mapcount() is then used in a couple more places, most notably to reduce false negatives in folio_likely_mapped_shared(), and many users of page_mapcount() are cleaned up (that's maybe why you got CCed on the full series, sorry sh+xtensa folks! :) ). The remaining s390x user and one KSM user of page_mapcount() are getting removed separately on the list right now. I have patches to handle the other KSM one, the khugepaged one and the kpagecount one; as they are not as "obvious", I will send them out separately in the future. Once that is all in place, I'm planning on moving page_mapcount() into fs/proc/task_mmu.c, the remaining user for the time being (and we can discuss at LSF/MM details on that :) ). I proposed the mapcount for large folios (previously called total mapcount) originally in part of [1] and I later included it in [2] where it is a requirement. In the meantime, I changed the patch a bit so I dropped all RB's. During the discussion of [1], Peter Xu correctly raised that this additional tracking might affect the performance when PMD->PTE remapping THPs. In the meantime. I addressed that by batching RMAP operations during fork(), unmap/zap and when PMD->PTE remapping THPs. Running some of my micro-benchmarks [3] (fork,munmap,cow-byte,remap) on 1 GiB of memory backed by folios with the same order, I observe the following on an Intel(R) Xeon(R) Silver 4210R CPU @ 2.40GHz tuned for reproducible results as much as possible: Standard deviation is mostly < 1%, except for order-9, where it's < 2% for fork() and munmap(). (1) Small folios are not affected (< 1%) in all 4 microbenchmarks. (2) Order-4 folios are not affected (< 1%) in all 4 microbenchmarks. A bit weird comapred to the other orders ... (3) PMD->PTE remapping of order-9 THPs is not affected (< 1%) (4) COW-byte (COWing a single page by writing a single byte) is not affected for any order (< 1 %). The page copy_fault overhead dominates everything. (5) fork() is mostly not affected (< 1%), except order-2, where we have a slowdown of ~4%. Already for order-3 folios, we're down to a slowdown of < 1%. (6) munmap() sees a slowdown by < 3% for some orders (order-5, order-6, order-9), but less for others (< 1% for order-4 and order-8, < 2% for order-2, order-3, order-7). Especially the fork() and munmap() benchmark are sensitive to each added instruction and other system noise, so I suspect some of the change and observed weirdness (order-4) is due to code layout changes and other factors, but not really due to the added atomics. So in the common case where we can batch, the added atomics don't really make a big difference, especially in light of the recent improvements for large folios that we recently gained due to batching. Surprisingly, for some cases where we cannot batch (e.g., COW), the added atomics don't seem to matter, because other overhead dominates. My fork and munmap micro-benchmarks don't cover cases where we cannot batch-process bigger parts of large folios. As this is not the common case, I'm not worrying about that right now. Future work is batching RMAP operations during swapout and folio migration. [1] https://lore.kernel.org/all/20230809083256.699513-1-david@redhat.com/ [2] https://lore.kernel.org/all/20231124132626.235350-1-david@redhat.com/ [3] https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/pte-mapped-folio-benchmarks.c?ref_type=heads This patch (of 18): Commit 53277bcf126d ("mm: support page_mapcount() on page_has_type() pages") made it impossible to detect mapcount underflows by treating any negative raw mapcount value as a mapcount of 0. We perform such underflow checks in zap_present_folio_ptes() and zap_huge_pmd(), which would currently no longer trigger. Let's check against PAGE_MAPCOUNT_RESERVE instead by using page_type_has_type(), like page_has_type() would, so we can still catch some underflows. [david@redhat.com: make page_mapcount() slighly more efficient] Link: https://lkml.kernel.org/r/1af4fd61-7926-47c8-be45-833c0dbec08b@redhat.com Link: https://lkml.kernel.org/r/20240409192301.907377-1-david@redhat.com Link: https://lkml.kernel.org/r/20240409192301.907377-2-david@redhat.com Fixes: 53277bcf126d ("mm: support page_mapcount() on page_has_type() pages") Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: Hugh Dickins <hughd@google.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Richard Chang <richardycc@google.com> Cc: Rich Felker <dalias@libc.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
follow_pte() is now our main function to lookup PTEs in VM_PFNMAP/VM_IO VMAs. Let's perform some more sanity checks to make this exported function harder to abuse. Further, extend the doc a bit, it still focuses on the KVM use case with MMU notifiers. Drop the KVM+follow_pfn() comment, follow_pfn() is no more, and we have other users nowadays. Also extend the doc regarding refcounted pages and the interaction with MMU notifiers. KVM is one example that uses MMU notifiers and can deal with refcounted pages properly. VFIO is one example that doesn't use MMU notifiers, and to prevent use-after-free, rejects refcounted pages: pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)). Protection changes are less of a concern for users like VFIO: the behavior is similar to longterm-pinning a page, and getting the PTE protection changed afterwards. The primary concern with refcounted pages is use-after-free, which callers should be aware of. Link: https://lkml.kernel.org/r/20240410155527.474777-4-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
... and centralize the VM_IO/VM_PFNMAP sanity check in there. We'll now also perform these sanity checks for direct follow_pte() invocations. For generic_access_phys(), we might now check multiple times: nothing to worry about, really. Link: https://lkml.kernel.org/r/20240410155527.474777-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Acked-by: Sean Christopherson <seanjc@google.com> [KVM] Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Patch series "mm: follow_pte() improvements and acrn follow_pte() fixes". Patch #1 fixes a bunch of issues I spotted in the acrn driver. It compiles, that's all I know. I'll appreciate some review and testing from acrn folks. Patch #2+#3 improve follow_pte(), passing a VMA instead of the MM, adding more sanity checks, and improving the documentation. Gave it a quick test on x86-64 using VM_PAT that ends up using follow_pte(). This patch (of 3): We currently miss handling various cases, resulting in a dangerous follow_pte() (previously follow_pfn()) usage. (1) We're not checking PTE write permissions. Maybe we should simply always require pte_write() like we do for pin_user_pages_fast(FOLL_WRITE)? Hard to tell, so let's check for ACRN_MEM_ACCESS_WRITE for now. (2) We're not rejecting refcounted pages. As we are not using MMU notifiers, messing with refcounted pages is dangerous and can result in use-after-free. Let's make sure to reject them. (3) We are only looking at the first PTE of a bigger range. We only lookup a single PTE, but memmap->len may span a larger area. Let's loop over all involved PTEs and make sure the PFN range is actually contiguous. Reject everything else: it couldn't have worked either way, and rather made use access PFNs we shouldn't be accessing. Link: https://lkml.kernel.org/r/20240410155527.474777-1-david@redhat.com Link: https://lkml.kernel.org/r/20240410155527.474777-2-david@redhat.com Fixes: 8a6e85f7 ("virt: acrn: obtain pa from VMA with PFNMAP flag") Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Huang Ying authored
During reviewing a patch to fix the race condition between free_swap_and_cache() and swapoff() [1], it was found that the document about how to prevent racing with swapoff isn't clear enough. Especially RCU read lock can prevent swapoff from freeing data structures. So, the document is added as comments. [1] https://lore.kernel.org/linux-mm/c8fe62d0-78b8-527a-5bef-ee663ccdc37a@huawei.com/ Link: https://lkml.kernel.org/r/20240407065450.498821-1-ying.huang@intel.comSigned-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Hao Ge authored
accountable_mapping() can return bool, so change it. Link: https://lkml.kernel.org/r/20240407063843.804274-1-gehao@kylinos.cnSigned-off-by: Hao Ge <gehao@kylinos.cn> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Hao Ge authored
vma_wants_writenotify() should return bool, so change it. Link: https://lkml.kernel.org/r/20240407062653.803142-1-gehao@kylinos.cnSigned-off-by: Hao Ge <gehao@kylinos.cn> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ho-Ren (Jack) Chuang authored
The current implementation treats emulated memory devices, such as CXL1.1 type3 memory, as normal DRAM when they are emulated as normal memory (E820_TYPE_RAM). However, these emulated devices have different characteristics than traditional DRAM, making it important to distinguish them. Thus, we modify the tiered memory initialization process to introduce a delay specifically for CPUless NUMA nodes. This delay ensures that the memory tier initialization for these nodes is deferred until HMAT information is obtained during the boot process. Finally, demotion tables are recalculated at the end. * late_initcall(memory_tier_late_init); Some device drivers may have initialized memory tiers between `memory_tier_init()` and `memory_tier_late_init()`, potentially bringing online memory nodes and configuring memory tiers. They should be excluded in the late init. * Handle cases where there is no HMAT when creating memory tiers There is a scenario where a CPUless node does not provide HMAT information. If no HMAT is specified, it falls back to using the default DRAM tier. * Introduce another new lock `default_dram_perf_lock` for adist calculation In the current implementation, iterating through CPUlist nodes requires holding the `memory_tier_lock`. However, `mt_calc_adistance()` will end up trying to acquire the same lock, leading to a potential deadlock. Therefore, we propose introducing a standalone `default_dram_perf_lock` to protect `default_dram_perf_*`. This approach not only avoids deadlock but also prevents holding a large lock simultaneously. * Upgrade `set_node_memory_tier` to support additional cases, including default DRAM, late CPUless, and hot-plugged initializations. To cover hot-plugged memory nodes, `mt_calc_adistance()` and `mt_find_alloc_memory_type()` are moved into `set_node_memory_tier()` to handle cases where memtype is not initialized and where HMAT information is available. * Introduce `default_memory_types` for those memory types that are not initialized by device drivers. Because late initialized memory and default DRAM memory need to be managed, a default memory type is created for storing all memory types that are not initialized by device drivers and as a fallback. Link: https://lkml.kernel.org/r/20240405000707.2670063-3-horenchuang@bytedance.comSigned-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Signed-off-by: Hao Xiang <hao.xiang@bytedance.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawie.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ho-Ren (Jack) Chuang authored
memory tier: dax/kmem: introduce an abstract layer for finding, allocating, and putting memory types Patch series "Improved Memory Tier Creation for CPUless NUMA Nodes", v11. When a memory device, such as CXL1.1 type3 memory, is emulated as normal memory (E820_TYPE_RAM), the memory device is indistinguishable from normal DRAM in terms of memory tiering with the current implementation. The current memory tiering assigns all detected normal memory nodes to the same DRAM tier. This results in normal memory devices with different attributions being unable to be assigned to the correct memory tier, leading to the inability to migrate pages between different types of memory. https://lore.kernel.org/linux-mm/PH0PR08MB7955E9F08CCB64F23963B5C3A860A@PH0PR08MB7955.namprd08.prod.outlook.com/T/ This patchset automatically resolves the issues. It delays the initialization of memory tiers for CPUless NUMA nodes until they obtain HMAT information and after all devices are initialized at boot time, eliminating the need for user intervention. If no HMAT is specified, it falls back to using `default_dram_type`. Example usecase: We have CXL memory on the host, and we create VMs with a new system memory device backed by host CXL memory. We inject CXL memory performance attributes through QEMU, and the guest now sees memory nodes with performance attributes in HMAT. With this change, we enable the guest kernel to construct the correct memory tiering for the memory nodes. This patch (of 2): Since different memory devices require finding, allocating, and putting memory types, these common steps are abstracted in this patch, enhancing the scalability and conciseness of the code. Link: https://lkml.kernel.org/r/20240405000707.2670063-1-horenchuang@bytedance.com Link: https://lkml.kernel.org/r/20240405000707.2670063-2-horenchuang@bytedance.comSigned-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawie.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Hao Xiang <hao.xiang@bytedance.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 26 Apr, 2024 30 commits
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Baolin Wang authored
As Vlastimil suggested in previous discussion[1], it doesn't make sense to set pageblock_order as MAX_PAGE_ORDER when hugetlbfs is not enabled and THP is enabled. Instead, it should be set to HPAGE_PMD_ORDER. [1] https://lore.kernel.org/all/76457ec5-d789-449b-b8ca-dcb6ceb12445@suse.cz/ Link: https://lkml.kernel.org/r/3d57d253070035bdc0f6d6e5681ce1ed0e1934f7.1712286863.git.baolin.wang@linux.alibaba.comSigned-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
Both callers already have a folio; pass it in and save a few calls to compound_head(). Link: https://lkml.kernel.org/r/20240405153228.2563754-6-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
It's now obvious that __folio_put_small() and __folio_put_large() do almost exactly the same thing. Inline them both into __folio_put(). Link: https://lkml.kernel.org/r/20240405153228.2563754-5-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
destroy_large_folio() has only one caller, move its contents there. Link: https://lkml.kernel.org/r/20240405153228.2563754-4-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
The pcp_allowed_order() check in free_the_page() was only being skipped by __folio_put_small() which is about to be rearranged. Link: https://lkml.kernel.org/r/20240405153228.2563754-3-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
Patch series "Clean up __folio_put()". With all the changes over the last few years, __folio_put_small and __folio_put_large have become almost identical to each other ... except you can't tell because they're spread over two files. Rearrange it all so that you can tell, and then inline them both into __folio_put(). This patch (of 5): free_unref_folios() can now handle non-hugetlb large folios, so keep normal large folios in the batch. hugetlb folios still need to be handled specially. [peterx@redhat.com: fix panic] Link: https://lkml.kernel.org/r/ZikjPB0Dt5HA8-uL@x1n Link: https://lkml.kernel.org/r/20240405153228.2563754-1-willy@infradead.org Link: https://lkml.kernel.org/r/20240405153228.2563754-2-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
Remove four hidden calls to compound_head(). Also exit early if the filesystem block size is >= PAGE_SIZE instead of just equal to PAGE_SIZE. Link: https://lkml.kernel.org/r/20240405180038.2618624-1-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Frank van der Linden authored
The hugetlb_cma code passes 0 in the order_per_bit argument to cma_declare_contiguous_nid (the alignment, computed using the page order, is correctly passed in). This causes a bit in the cma allocation bitmap to always represent a 4k page, making the bitmaps potentially very large, and slower. It would create bitmaps that would be pretty big. E.g. for a 4k page size on x86, hugetlb_cma=64G would mean a bitmap size of (64G / 4k) / 8 == 2M. With HUGETLB_PAGE_ORDER as order_per_bit, as intended, this would be (64G / 2M) / 8 == 4k. So, that's quite a difference. Also, this restricted the hugetlb_cma area to ((PAGE_SIZE << MAX_PAGE_ORDER) * 8) * PAGE_SIZE (e.g. 128G on x86) , since bitmap_alloc uses normal page allocation, and is thus restricted by MAX_PAGE_ORDER. Specifying anything about that would fail the CMA initialization. So, correctly pass in the order instead. Link: https://lkml.kernel.org/r/20240404162515.527802-2-fvdl@google.com Fixes: cf11e85f ("mm: hugetlb: optionally allocate gigantic hugepages using cma") Signed-off-by: Frank van der Linden <fvdl@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Frank van der Linden authored
cma_init_reserved_mem uses IS_ALIGNED to check if the size represented by one bit in the cma allocation bitmask is aligned with CMA_MIN_ALIGNMENT_BYTES (pageblock size). However, this is too strict, as this will fail if order_per_bit > pageblock_order, which is a valid configuration. We could check IS_ALIGNED both ways, but since both numbers are powers of two, no check is needed at all. Link: https://lkml.kernel.org/r/20240404162515.527802-1-fvdl@google.com Fixes: de9e14ee ("drivers: dma-contiguous: add initialization from device tree") Signed-off-by: Frank van der Linden <fvdl@google.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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John Hubbard authored
These build errors only occur if one fails to first run "make headers". However, that is a non-obvious and instrusive requirement, and so there was a discussion on how to get rid of it [1]. This uses that solution. These two files were created by taking a snapshot of the generated header files that are created via "make headers". These two files were copied from ./usr/include/linux/ to ./tools/include/uapi/linux/ . That fixes the selftests/mm build on today's Arch Linux (which required the userfaultfd.h) and Ubuntu 23.04 (which additionally required memfd.h). [1] https://lore.kernel.org/all/783a4178-1dec-4e30-989a-5174b8176b09@redhat.com/ Link: https://lkml.kernel.org/r/20240328033418.203790-3-jhubbard@nvidia.comSigned-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mark Brown <broonie@kernel.org> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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John Hubbard authored
Patch series "Fix selftests/mm build without requiring "make headers"". As mentioned in each patch, this implements the solution that we discussed in December 2023, in [1]. This turned out to be very clean and easy. It should also be quite easy to maintain. This should also make Peter Zijlstra happy, because it directly addresses the root cause of his "NAK NAK NAK" reply [2]. :) [1] https://lore.kernel.org/all/783a4178-1dec-4e30-989a-5174b8176b09@redhat.com/ [2] https://lore.kernel.org/lkml/20231103121652.GA6217@noisy.programming.kicks-ass.net/ This patch (of 2): Use tools/include/uapi/ files instead. These are obtained by taking a snapshot: run "make headers" at the top level, then copy the desired header file into the appropriate subdir in tools/uapi/. This was discussed and solved in [1]. However, even before copying any additional files there, there are already quite a few in tools/include/uapi already. And these will immediately fix a number of selftests/mm build failures. So this patch: a) Adds TOOLS_INCLUDES to selftests/lib.mk, so that all selftests can immediately and easily include the snapshotted header files. b) Uses $(TOOLS_INCLUDES) in the selftests/mm build. On today's Arch Linux, this already fixes all build errors except for a few userfaultfd.h (those will be addressed in a subsequent patch). [1] https://lore.kernel.org/all/783a4178-1dec-4e30-989a-5174b8176b09@redhat.com/ Link: https://lkml.kernel.org/r/20240328033418.203790-1-jhubbard@nvidia.com Link: https://lkml.kernel.org/r/20240328033418.203790-2-jhubbard@nvidia.comSigned-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mark Brown <broonie@kernel.org> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
hugetlb_wp() can use the struct vm_fault passed in from hugetlb_fault(). This alleviates the stack by consolidating 5 variables into a single struct. [vishal.moola@gmail.com: simplify hugetlb_wp() arguments] Link: https://lkml.kernel.org/r/ZhQtoFNZBNwBCeXn@fedora Link: https://lkml.kernel.org/r/20240401202651.31440-4-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
hugetlb_no_page() can use the struct vm_fault passed in from hugetlb_fault(). This alleviates the stack by consolidating 7 variables into a single struct. [vishal.moola@gmail.com: simplify hugetlb_no_page() arguments] Link: https://lkml.kernel.org/r/ZhQtN8y5zud8iI1u@fedora Link: https://lkml.kernel.org/r/20240401202651.31440-3-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
Patch series "Hugetlb fault path to use struct vm_fault", v2. This patchset converts the hugetlb fault path to use struct vm_fault. This helps make the code more readable, and alleviates the stack by allowing us to consolidate many fault-related variables into an individual pointer. This patch (of 3): Now that hugetlb_fault() has a vm_fault available for fault tracking, use it throughout. This cleans up the code by removing 2 variables, and prepares hugetlb_fault() to take in a struct vm_fault argument. Link: https://lkml.kernel.org/r/20240401202651.31440-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20240401202651.31440-2-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Muchun Song <muchun.song@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Jinjiang Tu authored
Since commit 3c6f33b7 ("mm/ksm: support fork/exec for prctl"), when a child process is forked, the MMF_VM_MERGE_ANY flag will be inherited in mm_init(). So, it's unnecessary to set the flag in ksm_fork(). Link: https://lkml.kernel.org/r/20240402024934.1093361-1-tujinjiang@huawei.comSigned-off-by: Jinjiang Tu <tujinjiang@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Rik van Riel <riel@surriel.com> Cc: Stefan Roesch <shr@devkernel.io> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's fixup the remaining comments to consistently call that thing "GUP-fast". With this change, we consistently call it "GUP-fast". Link: https://lkml.kernel.org/r/20240402125516.223131-4-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Nowadays, we call it "GUP-fast", the external interface includes functions like "get_user_pages_fast()", and we renamed all internal functions to reflect that as well. Let's make the config option reflect that. Link: https://lkml.kernel.org/r/20240402125516.223131-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Patch series "mm/gup: consistently call it GUP-fast". Some cleanups around function names, comments and the config option of "GUP-fast" -- GUP without "lock" safety belts on. With this cleanup it's easy to judge which functions are GUP-fast specific. We now consistently call it "GUP-fast", avoiding mixing it with "fast GUP", "lockless", or simply "gup" (which I always considered confusing in the ode). So the magic now happens in functions that contain "gup_fast", whereby gup_fast() is the entry point into that magic. Comments consistently reference either "GUP-fast" or "gup_fast()". This patch (of 3): Let's consistently call the "fast-only" part of GUP "GUP-fast" and rename all relevant internal functions to start with "gup_fast", to make it clearer that this is not ordinary GUP. The current mixture of "lockless", "gup" and "gup_fast" is confusing. Further, avoid the term "huge" when talking about a "leaf" -- for example, we nowadays check pmd_leaf() because pmd_huge() is gone. For the "hugepd"/"hugepte" stuff, it's part of the name ("is_hugepd"), so that stays. What remains is the "external" interface: * get_user_pages_fast_only() * get_user_pages_fast() * pin_user_pages_fast() The high-level internal functions for GUP-fast (+slow fallback) are now: * internal_get_user_pages_fast() -> gup_fast_fallback() * lockless_pages_from_mm() -> gup_fast() The basic GUP-fast walker functions: * gup_pgd_range() -> gup_fast_pgd_range() * gup_p4d_range() -> gup_fast_p4d_range() * gup_pud_range() -> gup_fast_pud_range() * gup_pmd_range() -> gup_fast_pmd_range() * gup_pte_range() -> gup_fast_pte_range() * gup_huge_pgd() -> gup_fast_pgd_leaf() * gup_huge_pud() -> gup_fast_pud_leaf() * gup_huge_pmd() -> gup_fast_pmd_leaf() The weird hugepd stuff: * gup_huge_pd() -> gup_fast_hugepd() * gup_hugepte() -> gup_fast_hugepte() The weird devmap stuff: * __gup_device_huge_pud() -> gup_fast_devmap_pud_leaf() * __gup_device_huge_pmd -> gup_fast_devmap_pmd_leaf() * __gup_device_huge() -> gup_fast_devmap_leaf() * undo_dev_pagemap() -> gup_fast_undo_dev_pagemap() Helper functions: * unpin_user_pages_lockless() -> gup_fast_unpin_user_pages() * gup_fast_folio_allowed() is already properly named * gup_fast_permitted() is already properly named With "gup_fast()", we now even have a function that is referred to in comment in mm/mmu_gather.c. Link: https://lkml.kernel.org/r/20240402125516.223131-1-david@redhat.com Link: https://lkml.kernel.org/r/20240402125516.223131-2-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
While this function returned a folio, it was still using __alloc_pages() and __free_pages(). Use __folio_alloc() and put_folio() instead. This actually removes a call to compound_head(), but more importantly, it prepares us for the move to memdescs. Link: https://lkml.kernel.org/r/20240402200656.913841-1-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
We don't actually use any parts of struct page; all we do is check the value of the pointer. So give the pointer the appropriate name & type. Link: https://lkml.kernel.org/r/20240402201659.918308-1-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The access_error() of vma is already checked under per-VMA lock, if it is a bad access, directly handle error, no need to retry with mmap_lock again. In order to release the correct lock, pass the mm_struct into bad_area_access_error(). If mm is NULL, release vma lock, or release mmap_lock. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Link: https://lkml.kernel.org/r/20240403083805.1818160-8-wangkefeng.wang@huawei.comReviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The vm_flags of vma already checked under per-VMA lock, if it is a bad access, directly handle error, no need to retry with mmap_lock again. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Link: https://lkml.kernel.org/r/20240403083805.1818160-7-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The access_error() of vma already checked under per-VMA lock, if it is a bad access, directly handle error, no need to retry with mmap_lock again. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. [wangkefeng.wang@huawei.com: use `cause' rather than SIGSEGV, per Alexandre] Link: https://lkml.kernel.org/r/ac978061-ce1a-40a4-8b0a-61883b42bea7@huawei.com Link: https://lkml.kernel.org/r/20240403083805.1818160-6-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The access_[pkey]_error() of vma already checked under per-VMA lock, if it is a bad access, directly handle error, no need to retry with mmap_lock again. In order to release the correct lock, pass the mm_struct into bad_access_pkey()/bad_access(), if mm is NULL, release vma lock, or release mmap_lock. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Link: https://lkml.kernel.org/r/20240403083805.1818160-5-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The vm_flags of vma already checked under per-VMA lock, if it is a bad access, directly set fault to VM_FAULT_BADACCESS and handle error, no need to retry with mmap_lock again. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Link: https://lkml.kernel.org/r/20240403083805.1818160-4-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
The vm_flags of vma already checked under per-VMA lock, if it is a bad access, directly set fault to VM_FAULT_BADACCESS and handle error, no need to retry with mmap_lock again, the latency time reduces 34% in 'lat_sig -P 1 prot lat_sig' from lmbench testcase. Since the page fault is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Link: https://lkml.kernel.org/r/20240403083805.1818160-3-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kefeng Wang authored
Patch series "arch/mm/fault: accelerate pagefault when badaccess", v2. After VMA lock-based page fault handling enabled, if bad access met under per-vma lock, it will fallback to mmap_lock-based handling, so it leads to unnessary mmap lock and vma find again. A test from lmbench shows 34% improve after this changes on arm64, lat_sig -P 1 prot lat_sig 0.29194 -> 0.19198 This patch (of 7): The __do_page_fault() only calls handle_mm_fault() after vm_flags checked, and it is only called by do_page_fault(), let's squash it into do_page_fault() to cleanup code. Link: https://lkml.kernel.org/r/20240403083805.1818160-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240403083805.1818160-2-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ryan Roberts authored
Rework madvise_cold_or_pageout_pte_range() to avoid splitting any large folio that is fully and contiguously mapped in the pageout/cold vm range. This change means that large folios will be maintained all the way to swap storage. This both improves performance during swap-out, by eliding the cost of splitting the folio, and sets us up nicely for maintaining the large folio when it is swapped back in (to be covered in a separate series). Folios that are not fully mapped in the target range are still split, but note that behavior is changed so that if the split fails for any reason (folio locked, shared, etc) we now leave it as is and move to the next pte in the range and continue work on the proceeding folios. Previously any failure of this sort would cause the entire operation to give up and no folios mapped at higher addresses were paged out or made cold. Given large folios are becoming more common, this old behavior would have likely lead to wasted opportunities. While we are at it, change the code that clears young from the ptes to use ptep_test_and_clear_young(), via the new mkold_ptes() batch helper function. This is more efficent than get_and_clear/modify/set, especially for contpte mappings on arm64, where the old approach would require unfolding/refolding and the new approach can be done in place. Link: https://lkml.kernel.org/r/20240408183946.2991168-8-ryan.roberts@arm.comSigned-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ryan Roberts authored
Now that swap supports storing all mTHP sizes, avoid splitting large folios before swap-out. This benefits performance of the swap-out path by eliding split_folio_to_list(), which is expensive, and also sets us up for swapping in large folios in a future series. If the folio is partially mapped, we continue to split it since we want to avoid the extra IO overhead and storage of writing out pages uneccessarily. THP_SWPOUT and THP_SWPOUT_FALLBACK counters should continue to count events only for PMD-mappable folios to avoid user confusion. THP_SWPOUT already has the appropriate guard. Add a guard for THP_SWPOUT_FALLBACK. It may be appropriate to add per-size counters in future. Link: https://lkml.kernel.org/r/20240408183946.2991168-7-ryan.roberts@arm.comSigned-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Barry Song <v-songbaohua@oppo.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ryan Roberts authored
Multi-size THP enables performance improvements by allocating large, pte-mapped folios for anonymous memory. However I've observed that on an arm64 system running a parallel workload (e.g. kernel compilation) across many cores, under high memory pressure, the speed regresses. This is due to bottlenecking on the increased number of TLBIs added due to all the extra folio splitting when the large folios are swapped out. Therefore, solve this regression by adding support for swapping out mTHP without needing to split the folio, just like is already done for PMD-sized THP. This change only applies when CONFIG_THP_SWAP is enabled, and when the swap backing store is a non-rotating block device. These are the same constraints as for the existing PMD-sized THP swap-out support. Note that no attempt is made to swap-in (m)THP here - this is still done page-by-page, like for PMD-sized THP. But swapping-out mTHP is a prerequisite for swapping-in mTHP. The main change here is to improve the swap entry allocator so that it can allocate any power-of-2 number of contiguous entries between [1, (1 << PMD_ORDER)]. This is done by allocating a cluster for each distinct order and allocating sequentially from it until the cluster is full. This ensures that we don't need to search the map and we get no fragmentation due to alignment padding for different orders in the cluster. If there is no current cluster for a given order, we attempt to allocate a free cluster from the list. If there are no free clusters, we fail the allocation and the caller can fall back to splitting the folio and allocates individual entries (as per existing PMD-sized THP fallback). The per-order current clusters are maintained per-cpu using the existing infrastructure. This is done to avoid interleving pages from different tasks, which would prevent IO being batched. This is already done for the order-0 allocations so we follow the same pattern. As is done for order-0 per-cpu clusters, the scanner now can steal order-0 entries from any per-cpu-per-order reserved cluster. This ensures that when the swap file is getting full, space doesn't get tied up in the per-cpu reserves. This change only modifies swap to be able to accept any order mTHP. It doesn't change the callers to elide doing the actual split. That will be done in separate changes. Link: https://lkml.kernel.org/r/20240408183946.2991168-6-ryan.roberts@arm.comSigned-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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