On 2022/6/23 14:42, Muchun Song wrote:
> On Thu, Jun 23, 2022 at 01:06:15AM +0800, Miaohe Lin wrote:
>> Use helper touch_pud to set pud accessed to simplify the code and improve
>> the readability. No functional change intended.
>>
>> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>> ---
>> mm/huge_memory.c | 14 ++++----------
>> 1 file changed, 4 insertions(+), 10 deletions(-)
>>
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index a26580da8011..a0c0e4bf9c1e 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -1281,21 +1281,15 @@ int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>>
>> void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
>> {
>> - pud_t entry;
>> - unsigned long haddr;
>> - bool write = vmf->flags & FAULT_FLAG_WRITE;
>> + int flags = 0;
>>
>> vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud);
>> if (unlikely(!pud_same(*vmf->pud, orig_pud)))
>> goto unlock;
>>
>> - entry = pud_mkyoung(orig_pud);
>> - if (write)
>> - entry = pud_mkdirty(entry);
>> - haddr = vmf->address & HPAGE_PUD_MASK;
>> - if (pudp_set_access_flags(vmf->vma, haddr, vmf->pud, entry, write))
>> - update_mmu_cache_pud(vmf->vma, vmf->address, vmf->pud);
>> -
>> + if (vmf->flags & FAULT_FLAG_WRITE)
>> + flags = FOLL_WRITE;
>
> FOLL_* flags are used for follow_page(). But huge_pud_set_accessed() is used in mm fault
> path. It is a little weird to me to use FOLL_WRITE here. I suggest replace the last
> parameter of touch_pud() to "bool writable", then passing "vmf->flags & FAULT_FLAG_WRITE"
> to it instead of converting from FAULT_FLAG* flag to FOLL* flag.
Sounds good. Thanks!
>
> Thanks.
>
>> + touch_pud(vmf->vma, vmf->address, vmf->pud, flags);
>> unlock:
>> spin_unlock(vmf->ptl);
>> }
>> --
>> 2.23.0
>>
>>
> .
>
