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| author | Alex Sierra <alex.sierra@amd.com> | 2022-07-15 10:05:11 -0500 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-07-17 17:14:28 -0700 |
| commit | 3218f8712d6bba1812efd5e0d66c1e15134f2a91 (patch) | |
| tree | 65d912c917fc8ba5a86cc1ada0c866f25f06216a /mm/khugepaged.c | |
| parent | f25cbb7a95a24ff9a2a3bebd308e303942ae6b2c (diff) | |
| download | linux-3218f8712d6bba1812efd5e0d66c1e15134f2a91.tar.bz2 | |
mm: handling Non-LRU pages returned by vm_normal_pages
With DEVICE_COHERENT, we'll soon have vm_normal_pages() return
device-managed anonymous pages that are not LRU pages. Although they
behave like normal pages for purposes of mapping in CPU page, and for COW.
They do not support LRU lists, NUMA migration or THP.
Callers to follow_page() currently don't expect ZONE_DEVICE pages,
however, with DEVICE_COHERENT we might now return ZONE_DEVICE. Check for
ZONE_DEVICE pages in applicable users of follow_page() as well.
Link: https://lkml.kernel.org/r/20220715150521.18165-5-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> [v2]
Reviewed-by: Alistair Popple <apopple@nvidia.com> [v6]
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 01e0d6336754..dea102170ab3 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -611,7 +611,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, goto out; } page = vm_normal_page(vma, address, pteval); - if (unlikely(!page)) { + if (unlikely(!page) || unlikely(is_zone_device_page(page))) { result = SCAN_PAGE_NULL; goto out; } @@ -1261,7 +1261,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, writable = true; page = vm_normal_page(vma, _address, pteval); - if (unlikely(!page)) { + if (unlikely(!page) || unlikely(is_zone_device_page(page))) { result = SCAN_PAGE_NULL; goto out_unmap; } @@ -1472,7 +1472,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) goto abort; page = vm_normal_page(vma, addr, *pte); - + if (WARN_ON_ONCE(page && is_zone_device_page(page))) + page = NULL; /* * Note that uprobe, debugger, or MAP_PRIVATE may change the * page table, but the new page will not be a subpage of hpage. @@ -1490,6 +1491,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) if (pte_none(*pte)) continue; page = vm_normal_page(vma, addr, *pte); + if (WARN_ON_ONCE(page && is_zone_device_page(page))) + goto abort; page_remove_rmap(page, vma, false); } |