On 02/28/2017 10:35 AM, Khalid Aziz wrote:
> diff --git a/mm/memory.c b/mm/memory.c
> index 6bf2b47..b086c76 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2658,6 +2658,7 @@ int do_swap_page(struct vm_fault *vmf)
> if (pte_swp_soft_dirty(vmf->orig_pte))
> pte = pte_mksoft_dirty(pte);
> set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte);
> + arch_do_swap_page(vma->vm_mm, vmf->address, pte, vmf->orig_pte);
> vmf->orig_pte = pte;
> if (page == swapcache) {
> do_page_add_anon_rmap(page, vma, vmf->address, exclusive);
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 91619fd..192c41a 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1538,6 +1538,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
> swp_pte = swp_entry_to_pte(entry);
> if (pte_soft_dirty(pteval))
> swp_pte = pte_swp_mksoft_dirty(swp_pte);
> + arch_unmap_one(mm, address, swp_pte, pteval);
> set_pte_at(mm, address, pte, swp_pte);
> } else if (PageAnon(page)) {
> swp_entry_t entry = { .val = page_private(page) };
> @@ -1571,6 +1572,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
> swp_pte = swp_entry_to_pte(entry);
> if (pte_soft_dirty(pteval))
> swp_pte = pte_swp_mksoft_dirty(swp_pte);
> + arch_unmap_one(mm, address, swp_pte, pteval);
> set_pte_at(mm, address, pte, swp_pte);
> } else
> dec_mm_counter(mm, mm_counter_file(page));
>From a core VM perspective, I'm fine with these hooks. It's minimally
invasive. It is missing some explanation in the *code* of why sparc is
doing this and when/why other architectures might want to use these
hooks. I think that would be awfully nice.
I still think the _current_ SPARC implementation of these hooks is
pretty broken because it doesn't allow more than one ADI tag within a
given page. But, fixing that is confined to sparc code and shouldn't
affect the core VM or these hooks.
I suspect these hooks are still quite incomplete. For instance, I do
not think KSM goes through these paths. Couldn't a process *lose* its
ADI tags when KSM merges an underlying physical page?
I think you need to resolve your outstanding issues (from your 0/4
patch) before anyone can really ack these. I suspect solving your
issues will change the number and placement of these hooks.
There is no mention in these patches of the effectively reduced virtual
address space. Why?
