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mm: rmap: use flush_cache_range() to flush cache for hugetlb pages

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Now we will use flush_cache_page() to flush cache for anonymous hugetlb
pages when unmapping or migrating a hugetlb page mapping, but the
flush_cache_page() only handles a PAGE_SIZE range on some architectures
(like arm32, arc and so on), which will cause potential cache issues. 
Thus change to use flush_cache_range() to cover the whole size of a
hugetlb page.

Link: https://lkml.kernel.org/r/dc903b378d1e2d26bbbe85409ab9d009631f175c.1651056365.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Baolin Wang 2022-05-09 18:20:53 -07:00 committed by Andrew Morton
parent 54205e9c54
commit dfc7ab5756
1 changed files with 48 additions and 42 deletions
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90
mm/rmap.c
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@ -1525,13 +1525,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
anon_exclusive = folio_test_anon(folio) &&
PageAnonExclusive(subpage);
if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
/*
* To call huge_pmd_unshare, i_mmap_rwsem must be
* held in write mode. Caller needs to explicitly
* do this outside rmap routines.
*/
VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
if (folio_test_hugetlb(folio)) {
/*
* huge_pmd_unshare may unmap an entire PMD page.
* There is no way of knowing exactly which PMDs may
@ -1541,22 +1535,31 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
*/
flush_cache_range(vma, range.start, range.end);
if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) {
flush_tlb_range(vma, range.start, range.end);
mmu_notifier_invalidate_range(mm, range.start,
range.end);
if (!folio_test_anon(folio)) {
/*
* The ref count of the PMD page was dropped
* which is part of the way map counting
* is done for shared PMDs. Return 'true'
* here. When there is no other sharing,
* huge_pmd_unshare returns false and we will
* unmap the actual page and drop map count
* to zero.
* To call huge_pmd_unshare, i_mmap_rwsem must be
* held in write mode. Caller needs to explicitly
* do this outside rmap routines.
*/
page_vma_mapped_walk_done(&pvmw);
break;
VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) {
flush_tlb_range(vma, range.start, range.end);
mmu_notifier_invalidate_range(mm, range.start,
range.end);
/*
* The ref count of the PMD page was dropped
* which is part of the way map counting
* is done for shared PMDs. Return 'true'
* here. When there is no other sharing,
* huge_pmd_unshare returns false and we will
* unmap the actual page and drop map count
* to zero.
*/
page_vma_mapped_walk_done(&pvmw);
break;
}
}
} else {
flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
@ -1879,13 +1882,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
anon_exclusive = folio_test_anon(folio) &&
PageAnonExclusive(subpage);
if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
/*
* To call huge_pmd_unshare, i_mmap_rwsem must be
* held in write mode. Caller needs to explicitly
* do this outside rmap routines.
*/
VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
if (folio_test_hugetlb(folio)) {
/*
* huge_pmd_unshare may unmap an entire PMD page.
* There is no way of knowing exactly which PMDs may
@ -1895,22 +1892,31 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
*/
flush_cache_range(vma, range.start, range.end);
if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) {
flush_tlb_range(vma, range.start, range.end);
mmu_notifier_invalidate_range(mm, range.start,
range.end);
if (!folio_test_anon(folio)) {
/*
* The ref count of the PMD page was dropped
* which is part of the way map counting
* is done for shared PMDs. Return 'true'
* here. When there is no other sharing,
* huge_pmd_unshare returns false and we will
* unmap the actual page and drop map count
* to zero.
* To call huge_pmd_unshare, i_mmap_rwsem must be
* held in write mode. Caller needs to explicitly
* do this outside rmap routines.
*/
page_vma_mapped_walk_done(&pvmw);
break;
VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) {
flush_tlb_range(vma, range.start, range.end);
mmu_notifier_invalidate_range(mm, range.start,
range.end);
/*
* The ref count of the PMD page was dropped
* which is part of the way map counting
* is done for shared PMDs. Return 'true'
* here. When there is no other sharing,
* huge_pmd_unshare returns false and we will
* unmap the actual page and drop map count
* to zero.
*/
page_vma_mapped_walk_done(&pvmw);
break;
}
}
} else {
flush_cache_page(vma, address, pte_pfn(*pvmw.pte));