On Thu, Aug 08, 2019 at 04:21:44PM -0700, John Hubbard wrote:
> On 8/8/19 11:55 AM, Bharath Vedartham wrote:
> ...
> > static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
> > int write, int atomic, unsigned long *gpa, int *pageshift)
> > {
> > struct mm_struct *mm = gts->ts_mm;
> > struct vm_area_struct *vma;
> > unsigned long paddr;
> > - int ret, ps;
> > + int ret;
> > + struct page *page;
> >
> > vma = find_vma(mm, vaddr);
> > if (!vma)
> > @@ -263,21 +187,33 @@ static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr,
> >
> > /*
> > * Atomic lookup is faster & usually works even if called in non-atomic
> > - * context.
> > + * context. get_user_pages_fast does atomic lookup before falling back to
> > + * slow gup.
> > */
> > rmb(); /* Must/check ms_range_active before loading PTEs */
> > - ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &ps);
> > - if (ret) {
> > - if (atomic)
> > + if (atomic) {
> > + ret = __get_user_pages_fast(vaddr, 1, write, &page);
> > + if (!ret)
> > goto upm;
> > - if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps))
> > + } else {
> > + ret = get_user_pages_fast(vaddr, 1, write ? FOLL_WRITE : 0, &page);
> > + if (!ret)
> > goto inval;
> > }
> > +
> > + paddr = page_to_phys(page);
> > + put_user_page(page);
> > +
> > + if (unlikely(is_vm_hugetlb_page(vma)))
> > + *pageshift = HPAGE_SHIFT;
> > + else
> > + *pageshift = PAGE_SHIFT;
> > +
> > if (is_gru_paddr(paddr))
> > goto inval;
> > - paddr = paddr & ~((1UL << ps) - 1);
> > + paddr = paddr & ~((1UL << *pageshift) - 1);
> > *gpa = uv_soc_phys_ram_to_gpa(paddr);
> > - *pageshift = ps;
>
> Why are you no longer setting *pageshift? There are a couple of callers
> that both use this variable.
I ll send v5 once your convinced by my argument that ps is not necessary
to set *pageshift and that *pageshift is being set.
Thank you
Bharath
>
> thanks,
> --
> John Hubbard
> NVIDIA
