Re: [PATCHv5 22/36] mm, hugetlb: switch hugetlbfs to multi-order radix-tree entries

From: Hillf Danton
Date: Wed Nov 30 2016 - 04:55:41 EST


On Tuesday, November 29, 2016 7:23 PM Kirill A. Shutemov wrote:
> @@ -607,10 +605,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
> }
>
> /* Set numa allocation policy based on index */
> - hugetlb_set_vma_policy(&pseudo_vma, inode, index);
> + hugetlb_set_vma_policy(&pseudo_vma, inode, index >> huge_page_order(h));
>
> /* addr is the offset within the file (zero based) */
> - addr = index * hpage_size;
> + addr = index << PAGE_SHIFT & ~huge_page_mask(h);
>
> /* mutex taken here, fault path and hole punch */
> hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping,

Seems we can't use index in computing hash as long as it isn't in huge page size.