| Message ID | 20190927070032.2129-1-richardw.yang@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/3] userfaultfd: use vma_pagesize for all huge page size calculation | expand |
On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: > In function __mcopy_atomic_hugetlb, we use two variables to deal with > huge page size: vma_hpagesize and huge_page_size. > > Since they are the same, it is not necessary to use two different > mechanism. This patch makes it consistent by all using vma_hpagesize. > > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, > pte_t dst_pteval; > > BUG_ON(dst_addr >= dst_start + len); > - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); > + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); > > /* > * Serialize via hugetlb_fault_mutex > @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, > mutex_lock(&hugetlb_fault_mutex_table[hash]); > > err = -ENOMEM; > - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); > + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); > if (!dst_pte) { > mutex_unlock(&hugetlb_fault_mutex_table[hash]); > goto out_unlock; > @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, > > err = copy_huge_page_from_user(page, > (const void __user *)src_addr, > - pages_per_huge_page(h), true); > + vma_hpagesize / PAGE_SIZE, > + true); > if (unlikely(err)) { > err = -EFAULT; > goto out; Looks right. We could go ahead and remove local variable `h', given that hugetlb_fault_mutex_hash() doesn't actually use its first arg..
On 9/27/19 3:10 PM, Andrew Morton wrote: > On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: > >> In function __mcopy_atomic_hugetlb, we use two variables to deal with >> huge page size: vma_hpagesize and huge_page_size. >> >> Since they are the same, it is not necessary to use two different >> mechanism. This patch makes it consistent by all using vma_hpagesize. >> >> --- a/mm/userfaultfd.c >> +++ b/mm/userfaultfd.c >> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> pte_t dst_pteval; >> >> BUG_ON(dst_addr >= dst_start + len); >> - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); >> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); >> >> /* >> * Serialize via hugetlb_fault_mutex >> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> mutex_lock(&hugetlb_fault_mutex_table[hash]); >> >> err = -ENOMEM; >> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); >> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); >> if (!dst_pte) { >> mutex_unlock(&hugetlb_fault_mutex_table[hash]); >> goto out_unlock; >> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> >> err = copy_huge_page_from_user(page, >> (const void __user *)src_addr, >> - pages_per_huge_page(h), true); >> + vma_hpagesize / PAGE_SIZE, >> + true); >> if (unlikely(err)) { >> err = -EFAULT; >> goto out; > > Looks right. > > We could go ahead and remove local variable `h', given that > hugetlb_fault_mutex_hash() doesn't actually use its first arg.. Good catch Andrew. I missed that, but I also wrote the original code that is being cleaned up. :) You can add, Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> to the series.
On Fri, Sep 27, 2019 at 03:10:33PM -0700, Andrew Morton wrote: >On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: > >> In function __mcopy_atomic_hugetlb, we use two variables to deal with >> huge page size: vma_hpagesize and huge_page_size. >> >> Since they are the same, it is not necessary to use two different >> mechanism. This patch makes it consistent by all using vma_hpagesize. >> >> --- a/mm/userfaultfd.c >> +++ b/mm/userfaultfd.c >> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> pte_t dst_pteval; >> >> BUG_ON(dst_addr >= dst_start + len); >> - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); >> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); >> >> /* >> * Serialize via hugetlb_fault_mutex >> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> mutex_lock(&hugetlb_fault_mutex_table[hash]); >> >> err = -ENOMEM; >> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); >> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); >> if (!dst_pte) { >> mutex_unlock(&hugetlb_fault_mutex_table[hash]); >> goto out_unlock; >> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >> >> err = copy_huge_page_from_user(page, >> (const void __user *)src_addr, >> - pages_per_huge_page(h), true); >> + vma_hpagesize / PAGE_SIZE, >> + true); >> if (unlikely(err)) { >> err = -EFAULT; >> goto out; > >Looks right. > >We could go ahead and remove local variable `h', given that >hugetlb_fault_mutex_hash() doesn't actually use its first arg.. Oops, haven't imagine h is not used in the function. Any historical reason to pass h in hugetlb_fault_mutex_hash()? Neither these two definition use it.
On Fri, Sep 27, 2019 at 03:21:38PM -0700, Mike Kravetz wrote: >On 9/27/19 3:10 PM, Andrew Morton wrote: >> On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: >> >>> In function __mcopy_atomic_hugetlb, we use two variables to deal with >>> huge page size: vma_hpagesize and huge_page_size. >>> >>> Since they are the same, it is not necessary to use two different >>> mechanism. This patch makes it consistent by all using vma_hpagesize. >>> >>> --- a/mm/userfaultfd.c >>> +++ b/mm/userfaultfd.c >>> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> pte_t dst_pteval; >>> >>> BUG_ON(dst_addr >= dst_start + len); >>> - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); >>> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); >>> >>> /* >>> * Serialize via hugetlb_fault_mutex >>> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> mutex_lock(&hugetlb_fault_mutex_table[hash]); >>> >>> err = -ENOMEM; >>> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); >>> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); >>> if (!dst_pte) { >>> mutex_unlock(&hugetlb_fault_mutex_table[hash]); >>> goto out_unlock; >>> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> >>> err = copy_huge_page_from_user(page, >>> (const void __user *)src_addr, >>> - pages_per_huge_page(h), true); >>> + vma_hpagesize / PAGE_SIZE, >>> + true); >>> if (unlikely(err)) { >>> err = -EFAULT; >>> goto out; >> >> Looks right. >> >> We could go ahead and remove local variable `h', given that >> hugetlb_fault_mutex_hash() doesn't actually use its first arg.. > >Good catch Andrew. I missed that, but I also wrote the original code that >is being cleaned up. :) > I did a cleanup to remove the first parameter of function hugetlb_fault_mutex_hash(). Look forward your comment. >You can add, >Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> >to the series. >-- >Mike Kravetz
On 9/28/19 5:45 PM, Wei Yang wrote: > On Fri, Sep 27, 2019 at 03:10:33PM -0700, Andrew Morton wrote: >> On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: >> >>> In function __mcopy_atomic_hugetlb, we use two variables to deal with >>> huge page size: vma_hpagesize and huge_page_size. >>> >>> Since they are the same, it is not necessary to use two different >>> mechanism. This patch makes it consistent by all using vma_hpagesize. >>> >>> --- a/mm/userfaultfd.c >>> +++ b/mm/userfaultfd.c >>> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> pte_t dst_pteval; >>> >>> BUG_ON(dst_addr >= dst_start + len); >>> - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); >>> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); >>> >>> /* >>> * Serialize via hugetlb_fault_mutex >>> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> mutex_lock(&hugetlb_fault_mutex_table[hash]); >>> >>> err = -ENOMEM; >>> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); >>> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); >>> if (!dst_pte) { >>> mutex_unlock(&hugetlb_fault_mutex_table[hash]); >>> goto out_unlock; >>> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>> >>> err = copy_huge_page_from_user(page, >>> (const void __user *)src_addr, >>> - pages_per_huge_page(h), true); >>> + vma_hpagesize / PAGE_SIZE, >>> + true); >>> if (unlikely(err)) { >>> err = -EFAULT; >>> goto out; >> >> Looks right. >> >> We could go ahead and remove local variable `h', given that >> hugetlb_fault_mutex_hash() doesn't actually use its first arg.. > > Oops, haven't imagine h is not used in the function. > > > Any historical reason to pass h in hugetlb_fault_mutex_hash()? Neither these > two definition use it. See 1b426bac66e6 ("hugetlb: use same fault hash key for shared and private mappings"). Prior to that change, the hash key for private mappings was created by: key[0] = (unsigned long) mm; key[1] = address >> huge_page_shift(h); When removing that code, I should have removed 'h'.
On Mon, Oct 07, 2019 at 03:55:21PM -0700, Mike Kravetz wrote: >On 9/28/19 5:45 PM, Wei Yang wrote: >> On Fri, Sep 27, 2019 at 03:10:33PM -0700, Andrew Morton wrote: >>> On Fri, 27 Sep 2019 15:00:30 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote: >>> >>>> In function __mcopy_atomic_hugetlb, we use two variables to deal with >>>> huge page size: vma_hpagesize and huge_page_size. >>>> >>>> Since they are the same, it is not necessary to use two different >>>> mechanism. This patch makes it consistent by all using vma_hpagesize. >>>> >>>> --- a/mm/userfaultfd.c >>>> +++ b/mm/userfaultfd.c >>>> @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>>> pte_t dst_pteval; >>>> >>>> BUG_ON(dst_addr >= dst_start + len); >>>> - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); >>>> + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); >>>> >>>> /* >>>> * Serialize via hugetlb_fault_mutex >>>> @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>>> mutex_lock(&hugetlb_fault_mutex_table[hash]); >>>> >>>> err = -ENOMEM; >>>> - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); >>>> + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); >>>> if (!dst_pte) { >>>> mutex_unlock(&hugetlb_fault_mutex_table[hash]); >>>> goto out_unlock; >>>> @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, >>>> >>>> err = copy_huge_page_from_user(page, >>>> (const void __user *)src_addr, >>>> - pages_per_huge_page(h), true); >>>> + vma_hpagesize / PAGE_SIZE, >>>> + true); >>>> if (unlikely(err)) { >>>> err = -EFAULT; >>>> goto out; >>> >>> Looks right. >>> >>> We could go ahead and remove local variable `h', given that >>> hugetlb_fault_mutex_hash() doesn't actually use its first arg.. >> >> Oops, haven't imagine h is not used in the function. >> >> >> Any historical reason to pass h in hugetlb_fault_mutex_hash()? Neither these >> two definition use it. > >See 1b426bac66e6 ("hugetlb: use same fault hash key for shared and private >mappings"). Prior to that change, the hash key for private mappings was >created by: > > key[0] = (unsigned long) mm; > key[1] = address >> huge_page_shift(h); > >When removing that code, I should have removed 'h'. Thanks for this information. >-- >Mike Kravetz
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index a998c1b4d8a1..01ad48621bb7 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -262,7 +262,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, pte_t dst_pteval; BUG_ON(dst_addr >= dst_start + len); - VM_BUG_ON(dst_addr & ~huge_page_mask(h)); + VM_BUG_ON(dst_addr & (vma_hpagesize - 1)); /* * Serialize via hugetlb_fault_mutex @@ -273,7 +273,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, mutex_lock(&hugetlb_fault_mutex_table[hash]); err = -ENOMEM; - dst_pte = huge_pte_alloc(dst_mm, dst_addr, huge_page_size(h)); + dst_pte = huge_pte_alloc(dst_mm, dst_addr, vma_hpagesize); if (!dst_pte) { mutex_unlock(&hugetlb_fault_mutex_table[hash]); goto out_unlock; @@ -300,7 +300,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, err = copy_huge_page_from_user(page, (const void __user *)src_addr, - pages_per_huge_page(h), true); + vma_hpagesize / PAGE_SIZE, + true); if (unlikely(err)) { err = -EFAULT; goto out;
In function __mcopy_atomic_hugetlb, we use two variables to deal with huge page size: vma_hpagesize and huge_page_size. Since they are the same, it is not necessary to use two different mechanism. This patch makes it consistent by all using vma_hpagesize. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> --- mm/userfaultfd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)