From: Mike Kravetz <mike.kravetz@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Wei Yang <richardw.yang@linux.intel.com>
Cc: aarcange@redhat.com, hughd@google.com, linux-mm@kvack.org
Subject: Re: [PATCH v2 1/3] userfaultfd: use vma_pagesize for all huge page size calculation
Date: Fri, 27 Sep 2019 15:21:38 -0700 [thread overview]
Message-ID: <d1415004-3775-6e75-0141-ff3db05f793e@oracle.com> (raw)
In-Reply-To: <20190927151033.aad57472652a0b3a6948df6e@linux-foundation.org>
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.
--
Mike Kravetz
next prev parent reply other threads:[~2019-09-27 22:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-27 7:00 [PATCH v2 1/3] userfaultfd: use vma_pagesize for all huge page size calculation Wei Yang
2019-09-27 7:00 ` [PATCH v2 2/3] userfaultfd: remove unnecessary warn_on in __mcopy_atomic_hugetlb Wei Yang
2019-09-27 7:00 ` [PATCH v2 3/3] userfaultfd: wrap the common dst_vma check into an inlined function Wei Yang
2019-09-27 22:10 ` [PATCH v2 1/3] userfaultfd: use vma_pagesize for all huge page size calculation Andrew Morton
2019-09-27 22:21 ` Mike Kravetz [this message]
2019-10-05 0:34 ` Wei Yang
2019-09-29 0:45 ` Wei Yang
2019-10-07 22:55 ` Mike Kravetz
2019-10-08 0:57 ` Wei Yang
2019-10-05 0:33 ` [PATCH] hugetlb: remove unused hstate in hugetlb_fault_mutex_hash() Wei Yang
2019-10-05 5:42 ` kbuild test robot
2019-10-05 5:43 ` kbuild test robot
2019-10-06 2:25 ` kbuild test robot
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