On Fri, 2015-07-03 at 16:47 +0800, wenwei tao wrote: > Hi Scott > > Thank you for your comments. > > Kernel already has that function: is_vm_hugetlb_page() , but the > original code didn't use it, > in order to keep the coding style of the original code, I didn't use it > either. > > For the sentence like: "vma->vm_flags & VM_HUGETLB" , hiding it behind > 'is_vm_hugetlb_page()' is ok, > but the sentence like: "vma->vm_flags & > (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)" appears in the patch 2/6, > is it better to hide the bit combinations behind the > is_vm_hugetlb_page() ? In my patch I just replaced it with > "vma->vm_flags & (VM_LOCKED|VM_PFNMAP) || (vma->vm_flags & > (VM_HUGETLB|VM_MERGEABLE)) == VM_HUGETLB". If you're going to do non-obvious things with the flags, it should be done in one place rather than throughout the code. Why would you do the above and not "vma->vm_flags & (VM_LOCKED | VM_PFNMAP) || is_vm_hugetlb_page(vma)"? -Scott -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>