| Message ID | 20190730055203.28467-9-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/13] amdgpu: remove -EAGAIN handling for hmm_range_fault | expand |
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@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 > +++ 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
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; >
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); for (; addr < end; addr += PAGE_SIZE, i++, pfn++) range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags;
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(-)