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authorBaolin Wang <baolin.wang@linux.alibaba.com>2022-05-09 18:20:53 -0700
committerAndrew Morton <akpm@linux-foundation.org>2022-05-13 07:20:07 -0700
commitdfc7ab57560da385f705b28e2bf50e3b90444a6b (patch)
treeb485b1d51b79da9e517ff06c36a49b8259c250b4 /mm/rmap.c
parent54205e9c5425049aef1bc7a812f890f00b5f79c7 (diff)
downloadlinux-dfc7ab57560da385f705b28e2bf50e3b90444a6b.tar.bz2
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>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c90
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));