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48b8d744ea841b8adf8d07bfe7a2d55f22e4d179
1015788 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Mike Kravetz
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48b8d744ea |
hugetlb: remove prep_compound_huge_page cleanup
Patch series "Fix prep_compound_gigantic_page ref count adjustment". These patches address the possible race between prep_compound_gigantic_page and __page_cache_add_speculative as described by Jann Horn in [1]. The first patch simply removes the unnecessary/obsolete helper routine prep_compound_huge_page to make the actual fix a little simpler. The second patch is the actual fix and has a detailed explanation in the commit message. This potential issue has existed for almost 10 years and I am unaware of anyone actually hitting the race. I did not cc stable, but would be happy to squash the patches and send to stable if anyone thinks that is a good idea. [1] https://lore.kernel.org/linux-mm/CAG48ez23q0Jy9cuVnwAe7t_fdhMk2S7N5Hdi-GLcCeq5bsfLxw@mail.gmail.com/ This patch (of 2): I could not think of a reliable way to recreate the issue for testing. Rather, I 'simulated errors' to exercise all the error paths. The routine prep_compound_huge_page is a simple wrapper to call either prep_compound_gigantic_page or prep_compound_page. However, it is only called from gather_bootmem_prealloc which only processes gigantic pages. Eliminate the routine and call prep_compound_gigantic_page directly. Link: https://lkml.kernel.org/r/20210622021423.154662-1-mike.kravetz@oracle.com Link: https://lkml.kernel.org/r/20210622021423.154662-2-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Youquan Song <youquan.song@intel.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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e6d41f12df |
mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
When using HUGETLB_PAGE_FREE_VMEMMAP, the freeing unused vmemmap pages associated with each HugeTLB page is default off. Now the vmemmap is PMD mapped. So there is no side effect when this feature is enabled with no HugeTLB pages in the system. Someone may want to enable this feature in the compiler time instead of using boot command line. So add a config to make it default on when someone do not want to enable it via command line. Link: https://lkml.kernel.org/r/20210616094915.34432-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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2d7a21715f |
mm: sparsemem: use huge PMD mapping for vmemmap pages
The preparation of splitting huge PMD mapping of vmemmap pages is ready, so switch the mapping from PTE to PMD. Link: https://lkml.kernel.org/r/20210616094915.34432-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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3bc2b6a725 |
mm: sparsemem: split the huge PMD mapping of vmemmap pages
Patch series "Split huge PMD mapping of vmemmap pages", v4. In order to reduce the difficulty of code review in series[1]. We disable huge PMD mapping of vmemmap pages when that feature is enabled. In this series, we do not disable huge PMD mapping of vmemmap pages anymore. We will split huge PMD mapping when needed. When HugeTLB pages are freed from the pool we do not attempt coalasce and move back to a PMD mapping because it is much more complex. [1] https://lore.kernel.org/linux-doc/20210510030027.56044-1-songmuchun@bytedance.com/ This patch (of 3): In [1], PMD mappings of vmemmap pages were disabled if the the feature hugetlb_free_vmemmap was enabled. This was done to simplify the initial implementation of vmmemap freeing for hugetlb pages. Now, remove this simplification by allowing PMD mapping and switching to PTE mappings as needed for allocated hugetlb pages. When a hugetlb page is allocated, the vmemmap page tables are walked to free vmemmap pages. During this walk, split huge PMD mappings to PTE mappings as required. In the unlikely case PTE pages can not be allocated, return error(ENOMEM) and do not optimize vmemmap of the hugetlb page. When HugeTLB pages are freed from the pool, we do not attempt to coalesce and move back to a PMD mapping because it is much more complex. [1] https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20210616094915.34432-1-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20210616094915.34432-2-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mina Almasry
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8cc5fcbb5b |
mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY
On UFFDIO_COPY, if we fail to copy the page contents while holding the
hugetlb_fault_mutex, we will drop the mutex and return to the caller after
allocating a page that consumed a reservation. In this case there may be
a fault that double consumes the reservation. To handle this, we free the
allocated page, fix the reservations, and allocate a temporary hugetlb
page and return that to the caller. When the caller does the copy outside
of the lock, we again check the cache, and allocate a page consuming the
reservation, and copy over the contents.
Test:
Hacked the code locally such that resv_huge_pages underflows produce
a warning and the copy_huge_page_from_user() always fails, then:
./tools/testing/selftests/vm/userfaultfd hugetlb_shared 10
2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success
./tools/testing/selftests/vm/userfaultfd hugetlb 10
2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success
Both tests succeed and produce no warnings. After the
test runs number of free/resv hugepages is correct.
[yuehaibing@huawei.com: remove set but not used variable 'vm_alloc_shared']
Link: https://lkml.kernel.org/r/20210601141610.28332-1-yuehaibing@huawei.com
[almasrymina@google.com: fix allocation error check and copy func name]
Link: https://lkml.kernel.org/r/20210605010626.1459873-1-almasrymina@google.com
Link: https://lkml.kernel.org/r/20210528005029.88088-1-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nanyong Sun
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22f3c95186 |
khugepaged: selftests: remove debug_cow
The debug_cow attribute had been removed since commit |
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Christophe Leroy
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a6a8f7c4aa |
powerpc/8xx: add support for huge pages on VMAP and VMALLOC
powerpc 8xx has 4 page sizes: - 4k - 16k - 512k - 8M At the time being, vmalloc and vmap only support huge pages which are leaf at PMD level. Here the PMD level is 4M, it doesn't correspond to any supported page size. For now, implement use of 16k and 512k pages which is done at PTE level. Support of 8M pages will be implemented later, it requires vmalloc to support hugepd tables. Link: https://lkml.kernel.org/r/8b972f1c03fb6bd59953035f0a3e4d26659de4f8.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Christophe Leroy
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3382bbee04 |
mm/vmalloc: enable mapping of huge pages at pte level in vmalloc
On some architectures like powerpc, there are huge pages that are mapped at pte level. Enable it in vmalloc. For that, architectures can provide arch_vmap_pte_supported_shift() that returns the shift for pages to map at pte level. Link: https://lkml.kernel.org/r/2c717e3b1fba1894d890feb7669f83025bfa314d.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Christophe Leroy
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f7ee1f13d6 |
mm/vmalloc: enable mapping of huge pages at pte level in vmap
On some architectures like powerpc, there are huge pages that are mapped at pte level. Enable it in vmap. For that, architectures can provide arch_vmap_pte_range_map_size() that returns the size of pages to map at pte level. Link: https://lkml.kernel.org/r/fb3ccc73377832ac6708181ec419128a2f98ce36.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Christophe Leroy
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c742199a01 |
mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge
For architectures with no PMD and/or no PUD, add stubs similar to what we
have for architectures without P4D.
[christophe.leroy@csgroup.eu: arm64: define only {pud/pmd}_{set/clear}_huge when useful]
Link: https://lkml.kernel.org/r/73ec95f40cafbbb69bdfb43a7f53876fd845b0ce.1620990479.git.christophe.leroy@csgroup.eu
[christophe.leroy@csgroup.eu: x86: define only {pud/pmd}_{set/clear}_huge when useful]
Link: https://lkml.kernel.org/r/7fbf1b6bc3e15c07c24fa45278d57064f14c896b.1620930415.git.christophe.leroy@csgroup.eu
Link: https://lkml.kernel.org/r/5ac5976419350e8e048d463a64cae449eb3ba4b0.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Christophe Leroy
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79c1c594f4 |
mm/hugetlb: change parameters of arch_make_huge_pte()
Patch series "Subject: [PATCH v2 0/5] Implement huge VMAP and VMALLOC on powerpc 8xx", v2. This series implements huge VMAP and VMALLOC on powerpc 8xx. Powerpc 8xx has 4 page sizes: - 4k - 16k - 512k - 8M At the time being, vmalloc and vmap only support huge pages which are leaf at PMD level. Here the PMD level is 4M, it doesn't correspond to any supported page size. For now, implement use of 16k and 512k pages which is done at PTE level. Support of 8M pages will be implemented later, it requires use of hugepd tables. To allow this, the architecture provides two functions: - arch_vmap_pte_range_map_size() which tells vmap_pte_range() what page size to use. A stub returning PAGE_SIZE is provided when the architecture doesn't provide this function. - arch_vmap_pte_supported_shift() which tells __vmalloc_node_range() what page shift to use for a given area size. A stub returning PAGE_SHIFT is provided when the architecture doesn't provide this function. This patch (of 5): At the time being, arch_make_huge_pte() has the following prototype: pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, struct page *page, int writable); vma is used to get the pages shift or size. vma is also used on Sparc to get vm_flags. page is not used. writable is not used. In order to use this function without a vma, replace vma by shift and flags. Also remove the used parameters. Link: https://lkml.kernel.org/r/cover.1620795204.git.christophe.leroy@csgroup.eu Link: https://lkml.kernel.org/r/f4633ac6a7da2f22f31a04a89e0a7026bb78b15b.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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babbbdd08a |
mm/huge_memory.c: don't discard hugepage if other processes are mapping it
If other processes are mapping any other subpages of the hugepage, i.e.
in pte-mapped thp case, page_mapcount() will return 1 incorrectly. Then
we would discard the page while other processes are still mapping it. Fix
it by using total_mapcount() which can tell whether other processes are
still mapping it.
Link: https://lkml.kernel.org/r/20210511134857.1581273-6-linmiaohe@huawei.com
Fixes:
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Miaohe Lin
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9132a468aa |
mm/huge_memory.c: remove unnecessary tlb_remove_page_size() for huge zero pmd
Commit |
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Miaohe Lin
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e6be37b2e7 |
mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()
Since commit |
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Miaohe Lin
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dfe5c51c60 |
mm/huge_memory.c: use page->deferred_list
Now that we can represent the location of ->deferred_list instead of ->mapping + ->index, make use of it to improve readability. Link: https://lkml.kernel.org/r/20210511134857.1581273-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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b2bd53f18b |
mm/huge_memory.c: remove dedicated macro HPAGE_CACHE_INDEX_MASK
Patch series "Cleanup and fixup for huge_memory:, v3. This series contains cleanups to remove dedicated macro and remove unnecessary tlb_remove_page_size() for huge zero pmd. Also this adds missing read-only THP checking for transparent_hugepage_enabled() and avoids discarding hugepage if other processes are mapping it. More details can be found in the respective changelogs. Thi patch (of 5): Rewrite the pgoff checking logic to remove macro HPAGE_CACHE_INDEX_MASK which is only used here to simplify the code. Link: https://lkml.kernel.org/r/20210511134857.1581273-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210511134857.1581273-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Song Liu <songliubraving@fb.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Shixin Liu
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b593b90dc9 |
mm/debug_vm_pgtable: remove redundant pfn_{pmd/pte}() and fix one comment mistake
Remove redundant pfn_{pmd/pte}() in {pmd/pte}_advanced_tests() and adjust
pfn_pud() in pud_advanced_tests() to make it similar with other two
functions.
In addition, the branch condition should be CONFIG_TRANSPARENT_HUGEPAGE
instead of CONFIG_ARCH_HAS_PTE_DEVMAP.
Link: https://lkml.kernel.org/r/20210419071820.750217-2-liushixin2@huawei.com
Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Shixin Liu
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5fe77be6bf |
mm/debug_vm_pgtable: move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE
The functions {pmd/pud}_set_huge and {pmd/pud}_clear_huge are not
dependent on THP. Hence move {pmd/pud}_huge_tests out of
CONFIG_TRANSPARENT_HUGEPAGE.
Link: https://lkml.kernel.org/r/20210419071820.750217-1-liushixin2@huawei.com
Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Muchun Song
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774905878f |
mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate
All the infrastructure is ready, so we introduce nr_free_vmemmap_pages field in the hstate to indicate how many vmemmap pages associated with a HugeTLB page that can be freed to buddy allocator. And initialize it in the hugetlb_vmemmap_init(). This patch is actual enablement of the feature. There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct page structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON to catch invalid usage of the tail struct page. Link: https://lkml.kernel.org/r/20210510030027.56044-10-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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4bab4964a5 |
mm: memory_hotplug: disable memmap_on_memory when hugetlb_free_vmemmap enabled
The parameter of memory_hotplug.memmap_on_memory is not compatible with hugetlb_free_vmemmap. So disable it when hugetlb_free_vmemmap is enabled. [akpm@linux-foundation.org: remove unneeded include, per Oscar] Link: https://lkml.kernel.org/r/20210510030027.56044-9-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Chen Huang <chenhuang5@huawei.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Muchun Song
|
e9fdff87e8 |
mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap
Add a kernel parameter hugetlb_free_vmemmap to enable the feature of freeing unused vmemmap pages associated with each hugetlb page on boot. We disable PMD mapping of vmemmap pages for x86-64 arch when this feature is enabled. Because vmemmap_remap_free() depends on vmemmap being base page mapped. Link: https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Muchun Song
|
ad2fa3717b |
mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page
When we free a HugeTLB page to the buddy allocator, we need to allocate
the vmemmap pages associated with it. However, we may not be able to
allocate the vmemmap pages when the system is under memory pressure. In
this case, we just refuse to free the HugeTLB page. This changes behavior
in some corner cases as listed below:
1) Failing to free a huge page triggered by the user (decrease nr_pages).
User needs to try again later.
2) Failing to free a surplus huge page when freed by the application.
Try again later when freeing a huge page next time.
3) Failing to dissolve a free huge page on ZONE_MOVABLE via
offline_pages().
This can happen when we have plenty of ZONE_MOVABLE memory, but
not enough kernel memory to allocate vmemmmap pages. We may even
be able to migrate huge page contents, but will not be able to
dissolve the source huge page. This will prevent an offline
operation and is unfortunate as memory offlining is expected to
succeed on movable zones. Users that depend on memory hotplug
to succeed for movable zones should carefully consider whether the
memory savings gained from this feature are worth the risk of
possibly not being able to offline memory in certain situations.
4) Failing to dissolve a huge page on CMA/ZONE_MOVABLE via
alloc_contig_range() - once we have that handling in place. Mainly
affects CMA and virtio-mem.
Similar to 3). virito-mem will handle migration errors gracefully.
CMA might be able to fallback on other free areas within the CMA
region.
Vmemmap pages are allocated from the page freeing context. In order for
those allocations to be not disruptive (e.g. trigger oom killer)
__GFP_NORETRY is used. hugetlb_lock is dropped for the allocation because
a non sleeping allocation would be too fragile and it could fail too
easily under memory pressure. GFP_ATOMIC or other modes to access memory
reserves is not used because we want to prevent consuming reserves under
heavy hugetlb freeing.
[mike.kravetz@oracle.com: fix dissolve_free_huge_page use of tail/head page]
Link: https://lkml.kernel.org/r/20210527231225.226987-1-mike.kravetz@oracle.com
[willy@infradead.org: fix alloc_vmemmap_page_list documentation warning]
Link: https://lkml.kernel.org/r/20210615200242.1716568-6-willy@infradead.org
Link: https://lkml.kernel.org/r/20210510030027.56044-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Muchun Song
|
b65d4adbc0 |
mm: hugetlb: defer freeing of HugeTLB pages
In the subsequent patch, we should allocate the vmemmap pages when freeing a HugeTLB page. But update_and_free_page() can be called under any context, so we cannot use GFP_KERNEL to allocate vmemmap pages. However, we can defer the actual freeing in a kworker to prevent from using GFP_ATOMIC to allocate the vmemmap pages. The __update_and_free_page() is where the call to allocate vmemmmap pages will be inserted. Link: https://lkml.kernel.org/r/20210510030027.56044-6-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Chen Huang <chenhuang5@huawei.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Muchun Song
|
f41f2ed43c |
mm: hugetlb: free the vmemmap pages associated with each HugeTLB page
Every HugeTLB has more than one struct page structure. We __know__ that we only use the first 4 (__NR_USED_SUBPAGE) struct page structures to store metadata associated with each HugeTLB. There are a lot of struct page structures associated with each HugeTLB page. For tail pages, the value of compound_head is the same. So we can reuse first page of tail page structures. We map the virtual addresses of the remaining pages of tail page structures to the first tail page struct, and then free these page frames. Therefore, we need to reserve two pages as vmemmap areas. When we allocate a HugeTLB page from the buddy, we can free some vmemmap pages associated with each HugeTLB page. It is more appropriate to do it in the prep_new_huge_page(). The free_vmemmap_pages_per_hpage(), which indicates how many vmemmap pages associated with a HugeTLB page can be freed, returns zero for now, which means the feature is disabled. We will enable it once all the infrastructure is there. [willy@infradead.org: fix documentation warning] Link: https://lkml.kernel.org/r/20210615200242.1716568-5-willy@infradead.org Link: https://lkml.kernel.org/r/20210510030027.56044-5-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Muchun Song
|
cd39d4e9e7 |
mm: hugetlb: gather discrete indexes of tail page
For HugeTLB page, there are more metadata to save in the struct page. But the head struct page cannot meet our needs, so we have to abuse other tail struct page to store the metadata. In order to avoid conflicts caused by subsequent use of more tail struct pages, we can gather these discrete indexes of tail struct page. In this case, it will be easier to add a new tail page index later. Link: https://lkml.kernel.org/r/20210510030027.56044-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Muchun Song
|
6be24bed9d |
mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAP
The option HUGETLB_PAGE_FREE_VMEMMAP allows for the freeing of some vmemmap pages associated with pre-allocated HugeTLB pages. For example, on X86_64 6 vmemmap pages of size 4KB each can be saved for each 2MB HugeTLB page. 4094 vmemmap pages of size 4KB each can be saved for each 1GB HugeTLB page. When a HugeTLB page is allocated or freed, the vmemmap array representing the range associated with the page will need to be remapped. When a page is allocated, vmemmap pages are freed after remapping. When a page is freed, previously discarded vmemmap pages must be allocated before remapping. The config option is introduced early so that supporting code can be written to depend on the option. The initial version of the code only provides support for x86-64. If config HAVE_BOOTMEM_INFO_NODE is enabled, the freeing vmemmap page code denpend on it to free vmemmap pages. Otherwise, just use free_reserved_page() to free vmemmmap pages. The routine register_page_bootmem_info() is used to register bootmem info. Therefore, make sure register_page_bootmem_info is enabled if HUGETLB_PAGE_FREE_VMEMMAP is defined. Link: https://lkml.kernel.org/r/20210510030027.56044-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Muchun Song
|
426e5c429d |
mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c
Patch series "Free some vmemmap pages of HugeTLB page", v23.
This patch series will free some vmemmap pages(struct page structures)
associated with each HugeTLB page when preallocated to save memory.
In order to reduce the difficulty of the first version of code review. In
this version, we disable PMD/huge page mapping of vmemmap if this feature
was enabled. This acutely eliminates a bunch of the complex code doing
page table manipulation. When this patch series is solid, we cam add the
code of vmemmap page table manipulation in the future.
The struct page structures (page structs) are used to describe a physical
page frame. By default, there is an one-to-one mapping from a page frame
to it's corresponding page struct.
The HugeTLB pages consist of multiple base page size pages and is
supported by many architectures. See hugetlbpage.rst in the Documentation
directory for more details. On the x86 architecture, HugeTLB pages of
size 2MB and 1GB are currently supported. Since the base page size on x86
is 4KB, a 2MB HugeTLB page consists of 512 base pages and a 1GB HugeTLB
page consists of 4096 base pages. For each base page, there is a
corresponding page struct.
Within the HugeTLB subsystem, only the first 4 page structs are used to
contain unique information about a HugeTLB page. HUGETLB_CGROUP_MIN_ORDER
provides this upper limit. The only 'useful' information in the remaining
page structs is the compound_head field, and this field is the same for
all tail pages.
By removing redundant page structs for HugeTLB pages, memory can returned
to the buddy allocator for other uses.
When the system boot up, every 2M HugeTLB has 512 struct page structs which
size is 8 pages(sizeof(struct page) * 512 / PAGE_SIZE).
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | -------------> | 1 |
| | +-----------+ +-----------+
| | | 2 | -------------> | 2 |
| | +-----------+ +-----------+
| | | 3 | -------------> | 3 |
| | +-----------+ +-----------+
| | | 4 | -------------> | 4 |
| 2MB | +-----------+ +-----------+
| | | 5 | -------------> | 5 |
| | +-----------+ +-----------+
| | | 6 | -------------> | 6 |
| | +-----------+ +-----------+
| | | 7 | -------------> | 7 |
| | +-----------+ +-----------+
| |
| |
| |
+-----------+
The value of page->compound_head is the same for all tail pages. The
first page of page structs (page 0) associated with the HugeTLB page
contains the 4 page structs necessary to describe the HugeTLB. The only
use of the remaining pages of page structs (page 1 to page 7) is to point
to page->compound_head. Therefore, we can remap pages 2 to 7 to page 1.
Only 2 pages of page structs will be used for each HugeTLB page. This
will allow us to free the remaining 6 pages to the buddy allocator.
Here is how things look after remapping.
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | -------------> | 1 |
| | +-----------+ +-----------+
| | | 2 | ----------------^ ^ ^ ^ ^ ^
| | +-----------+ | | | | |
| | | 3 | ------------------+ | | | |
| | +-----------+ | | | |
| | | 4 | --------------------+ | | |
| 2MB | +-----------+ | | |
| | | 5 | ----------------------+ | |
| | +-----------+ | |
| | | 6 | ------------------------+ |
| | +-----------+ |
| | | 7 | --------------------------+
| | +-----------+
| |
| |
| |
+-----------+
When a HugeTLB is freed to the buddy system, we should allocate 6 pages
for vmemmap pages and restore the previous mapping relationship.
Apart from 2MB HugeTLB page, we also have 1GB HugeTLB page. It is similar
to the 2MB HugeTLB page. We also can use this approach to free the
vmemmap pages.
In this case, for the 1GB HugeTLB page, we can save 4094 pages. This is a
very substantial gain. On our server, run some SPDK/QEMU applications
which will use 1024GB HugeTLB page. With this feature enabled, we can
save ~16GB (1G hugepage)/~12GB (2MB hugepage) memory.
Because there are vmemmap page tables reconstruction on the
freeing/allocating path, it increases some overhead. Here are some
overhead analysis.
1) Allocating 10240 2MB HugeTLB pages.
a) With this patch series applied:
# time echo 10240 > /proc/sys/vm/nr_hugepages
real 0m0.166s
user 0m0.000s
sys 0m0.166s
# bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
@start[tid]); delete(@start[tid]); }'
Attaching 2 probes...
@latency:
[8K, 16K) 5476 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[16K, 32K) 4760 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
[32K, 64K) 4 | |
b) Without this patch series:
# time echo 10240 > /proc/sys/vm/nr_hugepages
real 0m0.067s
user 0m0.000s
sys 0m0.067s
# bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
@start[tid]); delete(@start[tid]); }'
Attaching 2 probes...
@latency:
[4K, 8K) 10147 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[8K, 16K) 93 | |
Summarize: this feature is about ~2x slower than before.
2) Freeing 10240 2MB HugeTLB pages.
a) With this patch series applied:
# time echo 0 > /proc/sys/vm/nr_hugepages
real 0m0.213s
user 0m0.000s
sys 0m0.213s
# bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
@start[tid]); delete(@start[tid]); }'
Attaching 2 probes...
@latency:
[8K, 16K) 6 | |
[16K, 32K) 10227 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[32K, 64K) 7 | |
b) Without this patch series:
# time echo 0 > /proc/sys/vm/nr_hugepages
real 0m0.081s
user 0m0.000s
sys 0m0.081s
# bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
@start[tid]); delete(@start[tid]); }'
Attaching 2 probes...
@latency:
[4K, 8K) 6805 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[8K, 16K) 3427 |@@@@@@@@@@@@@@@@@@@@@@@@@@ |
[16K, 32K) 8 | |
Summary: The overhead of __free_hugepage is about ~2-3x slower than before.
Although the overhead has increased, the overhead is not significant.
Like Mike said, "However, remember that the majority of use cases create
HugeTLB pages at or shortly after boot time and add them to the pool. So,
additional overhead is at pool creation time. There is no change to
'normal run time' operations of getting a page from or returning a page to
the pool (think page fault/unmap)".
Despite the overhead and in addition to the memory gains from this series.
The following data is obtained by Joao Martins. Very thanks to his
effort.
There's an additional benefit which is page (un)pinners will see an improvement
and Joao presumes because there are fewer memmap pages and thus the tail/head
pages are staying in cache more often.
Out of the box Joao saw (when comparing linux-next against linux-next +
this series) with gup_test and pinning a 16G HugeTLB file (with 1G pages):
get_user_pages(): ~32k -> ~9k
unpin_user_pages(): ~75k -> ~70k
Usually any tight loop fetching compound_head(), or reading tail pages
data (e.g. compound_head) benefit a lot. There's some unpinning
inefficiencies Joao was fixing[2], but with that in added it shows even
more:
unpin_user_pages(): ~27k -> ~3.8k
[1] https://lore.kernel.org/linux-mm/20210409205254.242291-1-mike.kravetz@oracle.com/
[2] https://lore.kernel.org/linux-mm/20210204202500.26474-1-joao.m.martins@oracle.com/
This patch (of 9):
Move bootmem info registration common API to individual bootmem_info.c.
And we will use {get,put}_page_bootmem() to initialize the page for the
vmemmap pages or free the vmemmap pages to buddy in the later patch. So
move them out of CONFIG_MEMORY_HOTPLUG_SPARSE. This is just code movement
without any functional change.
Link: https://lkml.kernel.org/r/20210510030027.56044-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20210510030027.56044-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Mina Almasry <almasrymina@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Naoya Horiguchi
|
0ed950d1f2 |
mm,hwpoison: make get_hwpoison_page() call get_any_page()
__get_hwpoison_page() could fail to grab refcount by some race condition, so it's helpful if we can handle it by retrying. We already have retry logic, so make get_hwpoison_page() call get_any_page() when called from memory_failure(). As a result, get_hwpoison_page() can return negative values (i.e. error code), so some callers are also changed to handle error cases. soft_offline_page() does nothing for -EBUSY because that's enough and users in userspace can easily handle it. unpoison_memory() is also unchanged because it's broken and need thorough fixes (will be done later). Link: https://lkml.kernel.org/r/20210603233632.2964832-3-nao.horiguchi@gmail.com Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Naoya Horiguchi
|
a3f5d80ea4 |
mm,hwpoison: send SIGBUS with error virutal address
Now an action required MCE in already hwpoisoned address surely sends a SIGBUS to current process, but the SIGBUS doesn't convey error virtual address. That's not optimal for hwpoison-aware applications. To fix the issue, make memory_failure() call kill_accessing_process(), that does pagetable walk to find the error virtual address. It could find multiple virtual addresses for the same error page, and it seems hard to tell which virtual address is correct one. But that's rare and sending incorrect virtual address could be better than no address. So let's report the first found virtual address for now. [naoya.horiguchi@nec.com: fix walk_page_range() return] Link: https://lkml.kernel.org/r/20210603051055.GA244241@hori.linux.bs1.fc.nec.co.jp Link: https://lkml.kernel.org/r/20210521030156.2612074-4-nao.horiguchi@gmail.com Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Aili Yao <yaoaili@kingsoft.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jue Wang <juew@google.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
203c06eef5 |
mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
Dave Hansen reported the following about Feng Tang's tests on a machine
with persistent memory onlined as a DRAM-like device.
Feng Tang tossed these on a "Cascade Lake" system with 96 threads and
~512G of persistent memory and 128G of DRAM. The PMEM is in "volatile
use" mode and being managed via the buddy just like the normal RAM.
The PMEM zones are big ones:
present 65011712 = 248 G
high 134595 = 525 M
The PMEM nodes, of course, don't have any CPUs in them.
With your series, the pcp->high value per-cpu is 69584 pages or about
270MB per CPU. Scaled up by the 96 CPU threads, that's ~26GB of
worst-case memory in the pcps per zone, or roughly 10% of the size of
the zone.
This should not cause a problem as such although it could trigger reclaim
due to pages being stored on per-cpu lists for CPUs remote to a node. It
is not possible to treat cpuless nodes exactly the same as normal nodes
but the worst-case scenario can be mitigated by splitting pcp->high across
all online CPUs for cpuless memory nodes.
Link: https://lkml.kernel.org/r/20210616110743.GK30378@techsingularity.net
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Tang, Feng" <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
44042b4498 |
mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
The per-cpu page allocator (PCP) only stores order-0 pages. This means
that all THP and "cheap" high-order allocations including SLUB contends on
the zone->lock. This patch extends the PCP allocator to store THP and
"cheap" high-order pages. Note that struct per_cpu_pages increases in
size to 256 bytes (4 cache lines) on x86-64.
Note that this is not necessarily a universal performance win because of
how it is implemented. High-order pages can cause pcp->high to be
exceeded prematurely for lower-orders so for example, a large number of
THP pages being freed could release order-0 pages from the PCP lists.
Hence, much depends on the allocation/free pattern as observed by a single
CPU to determine if caching helps or hurts a particular workload.
That said, basic performance testing passed. The following is a netperf
UDP_STREAM test which hits the relevant patches as some of the network
allocations are high-order.
netperf-udp
5.13.0-rc2 5.13.0-rc2
mm-pcpburst-v3r4 mm-pcphighorder-v1r7
Hmean send-64 261.46 ( 0.00%) 266.30 * 1.85%*
Hmean send-128 516.35 ( 0.00%) 536.78 * 3.96%*
Hmean send-256 1014.13 ( 0.00%) 1034.63 * 2.02%*
Hmean send-1024 3907.65 ( 0.00%) 4046.11 * 3.54%*
Hmean send-2048 7492.93 ( 0.00%) 7754.85 * 3.50%*
Hmean send-3312 11410.04 ( 0.00%) 11772.32 * 3.18%*
Hmean send-4096 13521.95 ( 0.00%) 13912.34 * 2.89%*
Hmean send-8192 21660.50 ( 0.00%) 22730.72 * 4.94%*
Hmean send-16384 31902.32 ( 0.00%) 32637.50 * 2.30%*
Functionally, a patch like this is necessary to make bulk allocation of
high-order pages work with similar performance to order-0 bulk
allocations. The bulk allocator is not updated in this series as it would
have to be determined by bulk allocation users how they want to track the
order of pages allocated with the bulk allocator.
Link: https://lkml.kernel.org/r/20210611135753.GC30378@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mike Rapoport
|
43b02ba93b |
mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
After removal of the DISCONTIGMEM memory model the FLAT_NODE_MEM_MAP configuration option is equivalent to FLATMEM. Drop CONFIG_FLAT_NODE_MEM_MAP and use CONFIG_FLATMEM instead. Link: https://lkml.kernel.org/r/20210608091316.3622-10-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
a9ee6cf5c6 |
mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
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 <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
48d9f3355a |
docs: remove description of DISCONTIGMEM
Remove description of DISCONTIGMEM from the "Memory Models" document and update VM sysctl description so that it won't mention DISCONIGMEM. Link: https://lkml.kernel.org/r/20210608091316.3622-8-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
d3c251ab95 |
arch, mm: remove stale mentions of DISCONIGMEM
There are several places that mention DISCONIGMEM in comments or have stale code guarded by CONFIG_DISCONTIGMEM. Remove the dead code and update the comments. Link: https://lkml.kernel.org/r/20210608091316.3622-7-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
bb1c50d396 |
mm: remove CONFIG_DISCONTIGMEM
There are no architectures that support DISCONTIGMEM left. Remove the configuration option and the dead code it was guarding in the generic memory management code. Link: https://lkml.kernel.org/r/20210608091316.3622-6-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
5ab06e1099 |
m68k: remove support for DISCONTIGMEM
DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map in v5.11. Remove the support for DISCONTIGMEM entirely. Link: https://lkml.kernel.org/r/20210608091316.3622-5-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
8b793b4420 |
arc: remove support for DISCONTIGMEM
DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map in v5.11. Remove the support for DISCONTIGMEM entirely. Link: https://lkml.kernel.org/r/20210608091316.3622-4-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
e7793e5390 |
arc: update comment about HIGHMEM implementation
Arc does not use DISCONTIGMEM to implement high memory, update the comment describing how high memory works to reflect this. Link: https://lkml.kernel.org/r/20210608091316.3622-3-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
fdb7d9b7ac |
alpha: remove DISCONTIGMEM and NUMA
Patch series "Remove DISCONTIGMEM memory model", v3. SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a (long) while ago. The last architectures that used DISCONTIGMEM were updated to use other memory models in v5.11 and it is about the time to entirely remove DISCONTIGMEM from the kernel. This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory model selection in mm/Kconfig and replaces usage of redundant CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA and CONFIG_FLATMEM respectively. I've also removed NUMA support on alpha that was BROKEN for more than 15 years. There were also minor updates all over arch/ to remove mentions of DISCONTIGMEM in comments and #ifdefs. This patch (of 9): NUMA is marked broken on alpha for more than 15 years and DISCONTIGMEM was replaced with SPARSEMEM in v5.11. Remove both NUMA and DISCONTIGMEM support from alpha. Link: https://lkml.kernel.org/r/20210608091316.3622-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20210608091316.3622-2-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
21d02f8f84 |
mm/page_alloc: move free_the_page
Patch series "Allow high order pages to be stored on PCP", v2. The per-cpu page allocator (PCP) only handles order-0 pages. With the series "Use local_lock for pcp protection and reduce stat overhead" and "Calculate pcp->high based on zone sizes and active CPUs", it's now feasible to store high-order pages on PCP lists. This small series allows PCP to store "cheap" orders where cheap is determined by PAGE_ALLOC_COSTLY_ORDER and THP-sized allocations. This patch (of 2): In the next page, free_compount_page is going to use the common helper free_the_page. This patch moves the definition to ease review. No functional change. Link: https://lkml.kernel.org/r/20210603142220.10851-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20210603142220.10851-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Liu Shixin
|
f7ec104458 |
mm/page_alloc: fix counting of managed_pages
commit |
||
|
Dong Aisheng
|
e47aa90568 |
mm/page_alloc: improve memmap_pages dbg msg
Make debug message more accurate. Link: https://lkml.kernel.org/r/20210531091908.1738465-6-aisheng.dong@nxp.com Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dong Aisheng
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777c00f5ed |
mm: drop SECTION_SHIFT in code comments
Actually SECTIONS_SHIFT is used in the kernel code, so the code comments
is strictly incorrect. And since commit
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Mel Gorman
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74f4482209 |
mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
This introduces a new sysctl vm.percpu_pagelist_high_fraction. It is
similar to the old vm.percpu_pagelist_fraction. The old sysctl increased
both pcp->batch and pcp->high with the higher pcp->high potentially
reducing zone->lock contention. However, the higher pcp->batch value also
potentially increased allocation latency while the PCP was refilled. This
sysctl only adjusts pcp->high so that zone->lock contention is potentially
reduced but allocation latency during a PCP refill remains the same.
# grep -E "high:|batch" /proc/zoneinfo | tail -2
high: 649
batch: 63
# sysctl vm.percpu_pagelist_high_fraction=8
# grep -E "high:|batch" /proc/zoneinfo | tail -2
high: 35071
batch: 63
# sysctl vm.percpu_pagelist_high_fraction=64
high: 4383
batch: 63
# sysctl vm.percpu_pagelist_high_fraction=0
high: 649
batch: 63
[mgorman@techsingularity.net: fix documentation]
Link: https://lkml.kernel.org/r/20210528151010.GQ30378@techsingularity.net
Link: https://lkml.kernel.org/r/20210525080119.5455-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman
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c49c2c47da |
mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
When kswapd is active then direct reclaim is potentially active. In either case, it is possible that a zone would be balanced if pages were not trapped on PCP lists. Instead of draining remote pages, simply limit the size of the PCP lists while kswapd is active. Link: https://lkml.kernel.org/r/20210525080119.5455-6-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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3b12e7e979 |
mm/page_alloc: scale the number of pages that are batch freed
When a task is freeing a large number of order-0 pages, it may acquire the zone->lock multiple times freeing pages in batches. This may unnecessarily contend on the zone lock when freeing very large number of pages. This patch adapts the size of the batch based on the recent pattern to scale the batch size for subsequent frees. As the machines I used were not large enough to test this are not large enough to illustrate a problem, a debugging patch shows patterns like the following (slightly editted for clarity) Baseline vanilla kernel time-unmap-14426 [...] free_pcppages_bulk: free 63 count 378 high 378 time-unmap-14426 [...] free_pcppages_bulk: free 63 count 378 high 378 time-unmap-14426 [...] free_pcppages_bulk: free 63 count 378 high 378 time-unmap-14426 [...] free_pcppages_bulk: free 63 count 378 high 378 time-unmap-14426 [...] free_pcppages_bulk: free 63 count 378 high 378 With patches time-unmap-7724 [...] free_pcppages_bulk: free 126 count 814 high 814 time-unmap-7724 [...] free_pcppages_bulk: free 252 count 814 high 814 time-unmap-7724 [...] free_pcppages_bulk: free 504 count 814 high 814 time-unmap-7724 [...] free_pcppages_bulk: free 751 count 814 high 814 time-unmap-7724 [...] free_pcppages_bulk: free 751 count 814 high 814 Link: https://lkml.kernel.org/r/20210525080119.5455-5-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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04f8cfeaed |
mm/page_alloc: adjust pcp->high after CPU hotplug events
The PCP high watermark is based on the number of online CPUs so the
watermarks must be adjusted during CPU hotplug. At the time of
hot-remove, the number of online CPUs is already adjusted but during
hot-add, a delta needs to be applied to update PCP to the correct value.
After this patch is applied, the high watermarks are adjusted correctly.
# grep high: /proc/zoneinfo | tail -1
high: 649
# echo 0 > /sys/devices/system/cpu/cpu4/online
# grep high: /proc/zoneinfo | tail -1
high: 664
# echo 1 > /sys/devices/system/cpu/cpu4/online
# grep high: /proc/zoneinfo | tail -1
high: 649
Link: https://lkml.kernel.org/r/20210525080119.5455-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman
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b92ca18e8c |
mm/page_alloc: disassociate the pcp->high from pcp->batch
The pcp high watermark is based on the batch size but there is no
relationship between them other than it is convenient to use early in
boot.
This patch takes the first step and bases pcp->high on the zone low
watermark split across the number of CPUs local to a zone while the batch
size remains the same to avoid increasing allocation latencies. The
intent behind the default pcp->high is "set the number of PCP pages such
that if they are all full that background reclaim is not started
prematurely".
Note that in this patch the pcp->high values are adjusted after memory
hotplug events, min_free_kbytes adjustments and watermark scale factor
adjustments but not CPU hotplug events which is handled later in the
series.
On a test KVM instance;
Before grep -E "high:|batch" /proc/zoneinfo | tail -2
high: 378
batch: 63
After grep -E "high:|batch" /proc/zoneinfo | tail -2
high: 649
batch: 63
[mgorman@techsingularity.net: fix __setup_per_zone_wmarks for parallel memory
hotplug]
Link: https://lkml.kernel.org/r/20210528105925.GN30378@techsingularity.net
Link: https://lkml.kernel.org/r/20210525080119.5455-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman
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bbbecb35a4 |
mm/page_alloc: delete vm.percpu_pagelist_fraction
Patch series "Calculate pcp->high based on zone sizes and active CPUs", v2. The per-cpu page allocator (PCP) is meant to reduce contention on the zone lock but the sizing of batch and high is archaic and neither takes the zone size into account or the number of CPUs local to a zone. With larger zones and more CPUs per node, the contention is getting worse. Furthermore, the fact that vm.percpu_pagelist_fraction adjusts both batch and high values means that the sysctl can reduce zone lock contention but also increase allocation latencies. This series disassociates pcp->high from pcp->batch and then scales pcp->high based on the size of the local zone with limited impact to reclaim and accounting for active CPUs but leaves pcp->batch static. It also adapts the number of pages that can be on the pcp list based on recent freeing patterns. The motivation is partially to adjust to larger memory sizes but is also driven by the fact that large batches of page freeing via release_pages() often shows zone contention as a major part of the problem. Another is a bug report based on an older kernel where a multi-terabyte process can takes several minutes to exit. A workaround was to use vm.percpu_pagelist_fraction to increase the pcp->high value but testing indicated that a production workload could not use the same values because of an increase in allocation latencies. Unfortunately, I cannot reproduce this test case myself as the multi-terabyte machines are in active use but it should alleviate the problem. The series aims to address both and partially acts as a pre-requisite. pcp only works with order-0 which is useless for SLUB (when using high orders) and THP (unconditionally). To store high-order pages on PCP, the pcp->high values need to be increased first. This patch (of 6): The vm.percpu_pagelist_fraction is used to increase the batch and high limits for the per-cpu page allocator (PCP). The intent behind the sysctl is to reduce zone lock acquisition when allocating/freeing pages but it has a problem. While it can decrease contention, it can also increase latency on the allocation side due to unreasonably large batch sizes. This leads to games where an administrator adjusts percpu_pagelist_fraction on the fly to work around contention and allocation latency problems. This series aims to alleviate the problems with zone lock contention while avoiding the allocation-side latency problems. For the purposes of review, it's easier to remove this sysctl now and reintroduce a similar sysctl later in the series that deals only with pcp->high. Link: https://lkml.kernel.org/r/20210525080119.5455-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20210525080119.5455-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |