Messages in this thread | | | Subject | Re: [PATCH 08/13] mm: remove the mask variable in hmm_vma_walk_hugetlb_entry | From | Ralph Campbell <> | Date | Tue, 30 Jul 2019 18:01:11 -0700 |
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On 7/29/19 10:51 PM, Christoph Hellwig wrote: > The pagewalk code already passes the value as the hmask parameter. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > mm/hmm.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/mm/hmm.c b/mm/hmm.c > index f26d6abc4ed2..88b77a4a6a1e 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -771,19 +771,16 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, > struct mm_walk *walk) > { > #ifdef CONFIG_HUGETLB_PAGE > - unsigned long addr = start, i, pfn, mask; > + unsigned long addr = start, i, pfn; > struct hmm_vma_walk *hmm_vma_walk = walk->private; > struct hmm_range *range = hmm_vma_walk->range; > struct vm_area_struct *vma = walk->vma; > - struct hstate *h = hstate_vma(vma); > uint64_t orig_pfn, cpu_flags; > bool fault, write_fault; > spinlock_t *ptl; > pte_t entry; > int ret = 0; > > - mask = huge_page_size(h) - 1; > - > ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte); > entry = huge_ptep_get(pte); > > @@ -799,7 +796,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, > goto unlock; > } > > - pfn = pte_pfn(entry) + ((start & mask) >> PAGE_SHIFT); > + pfn = pte_pfn(entry) + ((start & hmask) >> PAGE_SHIFT);
This needs to be "~hmask" so that the upper bits of the start address are not added to the pfn. It's the middle bits of the address that offset into the huge page that are needed.
> for (; addr < end; addr += PAGE_SIZE, i++, pfn++) > range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | > cpu_flags; >
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