On 20/12/2023 22:44, David Hildenbrand wrote:
> Let's convert zap_pte_range() and closely-related
> tlb_flush_rmap_batch(). While at it, perform some more folio conversion
> in zap_pte_range().
>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> mm/memory.c | 23 +++++++++++++----------
> mm/mmu_gather.c | 2 +-
> 2 files changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 6552ea27b0bfa..eda2181275d9b 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1434,6 +1434,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
> arch_enter_lazy_mmu_mode();
> do {
> pte_t ptent = ptep_get(pte);
> + struct folio *folio;
> struct page *page;
>
> if (pte_none(ptent))
> @@ -1459,21 +1460,22 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
> continue;
> }
>
> + folio = page_folio(page);
> delay_rmap = 0;
> - if (!PageAnon(page)) {
> + if (!folio_test_anon(folio)) {
> if (pte_dirty(ptent)) {
> - set_page_dirty(page);
> + folio_set_dirty(folio);
Is this foliation change definitely correct? I note that set_page_dirty() is
defined as this:
bool set_page_dirty(struct page *page)
{
return folio_mark_dirty(page_folio(page));
}
And folio_mark_dirty() is doing more than just setting teh PG_dirty bit. In my
equivalent change, as part of the contpte series, I've swapped set_page_dirty()
for folio_mark_dirty().
> if (tlb_delay_rmap(tlb)) {
> delay_rmap = 1;
> force_flush = 1;
> }
> }
> if (pte_young(ptent) && likely(vma_has_recency(vma)))
> - mark_page_accessed(page);
> + folio_mark_accessed(folio);
> }
> rss[mm_counter(page)]--;
> if (!delay_rmap) {
> - page_remove_rmap(page, vma, false);
> + folio_remove_rmap_pte(folio, page, vma);
> if (unlikely(page_mapcount(page) < 0))
> print_bad_pte(vma, addr, ptent, page);
> }
> @@ -1489,6 +1491,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
> if (is_device_private_entry(entry) ||
> is_device_exclusive_entry(entry)) {
> page = pfn_swap_entry_to_page(entry);
> + folio = page_folio(page);
> if (unlikely(!should_zap_page(details, page)))
> continue;
> /*
> @@ -1500,8 +1503,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
> WARN_ON_ONCE(!vma_is_anonymous(vma));
> rss[mm_counter(page)]--;
> if (is_device_private_entry(entry))
> - page_remove_rmap(page, vma, false);
> - put_page(page);
> + folio_remove_rmap_pte(folio, page, vma);
> + folio_put(folio);
> } else if (!non_swap_entry(entry)) {
> /* Genuine swap entry, hence a private anon page */
> if (!should_zap_cows(details))
> @@ -3220,10 +3223,10 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
> * threads.
> *
> * The critical issue is to order this
> - * page_remove_rmap with the ptp_clear_flush above.
> - * Those stores are ordered by (if nothing else,)
> + * folio_remove_rmap_pte() with the ptp_clear_flush
> + * above. Those stores are ordered by (if nothing else,)
> * the barrier present in the atomic_add_negative
> - * in page_remove_rmap.
> + * in folio_remove_rmap_pte();
> *
> * Then the TLB flush in ptep_clear_flush ensures that
> * no process can access the old page before the
> @@ -3232,7 +3235,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
> * mapcount is visible. So transitively, TLBs to
> * old page will be flushed before it can be reused.
> */
> - page_remove_rmap(vmf->page, vma, false);
> + folio_remove_rmap_pte(old_folio, vmf->page, vma);
> }
>
> /* Free the old page.. */
> diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
> index 4f559f4ddd217..604ddf08affed 100644
> --- a/mm/mmu_gather.c
> +++ b/mm/mmu_gather.c
> @@ -55,7 +55,7 @@ static void tlb_flush_rmap_batch(struct mmu_gather_batch *batch, struct vm_area_
>
> if (encoded_page_flags(enc)) {
> struct page *page = encoded_page_ptr(enc);
> - page_remove_rmap(page, vma, false);
> + folio_remove_rmap_pte(page_folio(page), page, vma);
> }
> }
> }
