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Subject: Re: [PATCH v2] mm/hugetlb: fix a addressing exception caused by
 huge_pte_offset()
To:     Jason Gunthorpe <jgg@ziepe.ca>,
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From:   Mike Kravetz <mike.kravetz@oracle.com>
Message-ID: <98d35563-8af0-2693-7e76-e6435da0bbee@oracle.com>
Date:   Tue, 24 Mar 2020 08:25:09 -0700
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On 3/24/20 4:55 AM, Jason Gunthorpe wrote:
> Also, since CH moved all the get_user_pages_fast code out of the
> arch's many/all archs can drop their arch specific version of this
> routine. This is really just a specialized version of gup_fast's
> algorithm..
> 
> (also the arch versions seem different, why do some return actual
>  ptes, not null?)

Not sure I understand that last question.  The return value should be
a *pte or null.

/*
 * huge_pte_offset() - Walk the page table to resolve the hugepage
 * entry at address @addr
 *
 * Return: Pointer to page table or swap entry (PUD or PMD) for
 * address @addr, or NULL if a p*d_none() entry is encountered and the
 * size @sz doesn't match the hugepage size at this level of the page
 * table.
 */
-- 
Mike Kravetz