Re: [PATCH 19/46] hugetlb: add HGM support for follow_hugetlb_page

[Peter Xu]

On Thu, Jan 05, 2023 at 10:18:17AM +0000, James Houghton wrote:
> @@ -6649,13 +6655,20 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
>  		 */
>  		if (absent && (flags & FOLL_DUMP) &&
>  		    !hugetlbfs_pagecache_present(h, vma, vaddr)) {
> -			if (pte)
> +			if (ptep)
>  				spin_unlock(ptl);
>  			hugetlb_vma_unlock_read(vma);
>  			remainder = 0;
>  			break;
>  		}
>  
> +		if (!absent && pte_present(pte) &&
> +				!hugetlb_pte_present_leaf(&hpte, pte)) {
> +			/* We raced with someone splitting the PTE, so retry. */
> +			spin_unlock(ptl);

vma unlock missing here.

> +			continue;
> +		}

-- 
Peter Xu