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-rw-r--r--mm/hugetlb.c27
1 files changed, 21 insertions, 6 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f025d234522f..a1baa198519a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2973,7 +2973,7 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid)
struct huge_bootmem_page *m = NULL; /* initialize for clang */
int nr_nodes, node;
- if (nid >= nr_online_nodes)
+ if (nid != NUMA_NO_NODE && nid >= nr_online_nodes)
return 0;
/* do node specific alloc */
if (nid != NUMA_NO_NODE) {
@@ -4919,9 +4919,9 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
move_huge_pte(vma, old_addr, new_addr, src_pte);
}
- i_mmap_unlock_write(mapping);
flush_tlb_range(vma, old_end - len, old_end);
mmu_notifier_invalidate_range_end(&range);
+ i_mmap_unlock_write(mapping);
return len + old_addr - old_end;
}
@@ -4939,6 +4939,7 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
struct mmu_notifier_range range;
+ bool force_flush = false;
WARN_ON(!is_vm_hugetlb_page(vma));
BUG_ON(start & ~huge_page_mask(h));
@@ -4967,10 +4968,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
ptl = huge_pte_lock(h, mm, ptep);
if (huge_pmd_unshare(mm, vma, &address, ptep)) {
spin_unlock(ptl);
- /*
- * We just unmapped a page of PMDs by clearing a PUD.
- * The caller's TLB flush range should cover this area.
- */
+ tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE);
+ force_flush = true;
continue;
}
@@ -5027,6 +5026,22 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
}
mmu_notifier_invalidate_range_end(&range);
tlb_end_vma(tlb, vma);
+
+ /*
+ * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We
+ * could defer the flush until now, since by holding i_mmap_rwsem we
+ * guaranteed that the last refernece would not be dropped. But we must
+ * do the flushing before we return, as otherwise i_mmap_rwsem will be
+ * dropped and the last reference to the shared PMDs page might be
+ * dropped as well.
+ *
+ * In theory we could defer the freeing of the PMD pages as well, but
+ * huge_pmd_unshare() relies on the exact page_count for the PMD page to
+ * detect sharing, so we cannot defer the release of the page either.
+ * Instead, do flush now.
+ */
+ if (force_flush)
+ tlb_flush_mmu_tlbonly(tlb);
}
void __unmap_hugepage_range_final(struct mmu_gather *tlb,