On 12.11.22 00:26, Mike Kravetz wrote:
Expose the routine zap_page_range_single to zap a range within a single
vma. The madvise routine madvise_dontneed_single_vma can use this
routine as it explicitly operates on a single vma. Also, update the mmu
notification range in zap_page_range_single to take hugetlb pmd sharing
into account. This is required as MADV_DONTNEED supports hugetlb vmas.
Fixes: 90e7e7f5ef3f ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reported-by: Wei Chen <harperchen1110@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
[...]
-/*
- * Parameter block passed down to zap_pte_range in exceptional cases.
- */
-struct zap_details {
- struct folio *single_folio; /* Locked folio to be unmapped */
- bool even_cows; /* Zap COWed private pages too? */
- zap_flags_t zap_flags; /* Extra flags for zapping */
-};
-
/* Whether we should zap all COWed (private) pages too */
static inline bool should_zap_cows(struct zap_details *details)
{
@@ -1736,19 +1727,27 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
*
* The range must fit into one VMA.
*/
-static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
+void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details)
{
+ unsigned long end = address + size;
Could make that const.
struct mmu_notifier_range range;
struct mmu_gather tlb;
lru_add_drain();
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
- address, address + size);
+ address, end);
+ if (is_vm_hugetlb_page(vma))
+ adjust_range_if_pmd_sharing_possible(vma, &range.start,
+ &range.end);
tlb_gather_mmu(&tlb, vma->vm_mm);
update_hiwater_rss(vma->vm_mm);
mmu_notifier_invalidate_range_start(&range);
- unmap_single_vma(&tlb, vma, address, range.end, details);
+ /*
+ * unmap 'address-end' not 'range.start-range.end' as range
+ * could have been expanded for hugetlb pmd sharing.
+ */
+ unmap_single_vma(&tlb, vma, address, end, details);
mmu_notifier_invalidate_range_end(&range);
tlb_finish_mmu(&tlb);
}
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
--
Thanks,
David / dhildenb
