diff options
author | Baolin Wang <baolin.wang@linux.alibaba.com> | 2022-05-10 04:20:53 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2022-05-13 17:20:07 +0300 |
commit | dfc7ab57560da385f705b28e2bf50e3b90444a6b (patch) | |
tree | b485b1d51b79da9e517ff06c36a49b8259c250b4 | |
parent | 54205e9c5425049aef1bc7a812f890f00b5f79c7 (diff) | |
download | linux-dfc7ab57560da385f705b28e2bf50e3b90444a6b.tar.xz |
mm: rmap: use flush_cache_range() to flush cache for hugetlb pages
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>
-rw-r--r-- | mm/rmap.c | 90 |
1 files changed, 48 insertions, 42 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 829b2f9486c6..f73a62c5b180 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -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)); |