On Tue, Jul 30, 2019 at 08:51:58AM +0300, Christoph Hellwig wrote:
> The pagewalk code already passes the value as the hmask parameter.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> 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
> +++ 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);
I don't know this hstate stuff, but this doesn't look the same?
static int walk_hugetlb_range(unsigned long addr, unsigned long end, {
struct hstate *h = hstate_vma(vma);
unsigned long hmask = huge_page_mask(h); // aka h->mask
err = walk->hugetlb_entry(pte, hmask, addr, next, walk);
And the first place I found setting h->mask is:
void __init hugetlb_add_hstate(unsigned int order) {
h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
Compared with
mask = huge_page_size(h) - 1;
= ((unsigned long)PAGE_SIZE << h->order) - 1
Looks like hmask == ~mask
?
Jason
