From e4a2ed94908cc0104b8826ed8d831661ed1c3ea1 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 2 Sep 2022 20:46:37 +0100 Subject: [PATCH] mm: convert do_wp_page() to use a folio Saves many calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-42-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/memory.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 0018df3f..2f1397b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3368,6 +3368,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) { const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; struct vm_area_struct *vma = vmf->vma; + struct folio *folio; VM_BUG_ON(unshare && (vmf->flags & FAULT_FLAG_WRITE)); VM_BUG_ON(!unshare && !(vmf->flags & FAULT_FLAG_WRITE)); @@ -3414,48 +3415,47 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) * Take out anonymous pages first, anonymous shared vmas are * not dirty accountable. */ - if (PageAnon(vmf->page)) { - struct page *page = vmf->page; - + folio = page_folio(vmf->page); + if (folio_test_anon(folio)) { /* * If the page is exclusive to this process we must reuse the * page without further checks. */ - if (PageAnonExclusive(page)) + if (PageAnonExclusive(vmf->page)) goto reuse; /* - * We have to verify under page lock: these early checks are - * just an optimization to avoid locking the page and freeing + * We have to verify under folio lock: these early checks are + * just an optimization to avoid locking the folio and freeing * the swapcache if there is little hope that we can reuse. * - * PageKsm() doesn't necessarily raise the page refcount. + * KSM doesn't necessarily raise the folio refcount. */ - if (PageKsm(page) || page_count(page) > 3) + if (folio_test_ksm(folio) || folio_ref_count(folio) > 3) goto copy; - if (!PageLRU(page)) + if (!folio_test_lru(folio)) /* * Note: We cannot easily detect+handle references from - * remote LRU pagevecs or references to PageLRU() pages. + * remote LRU pagevecs or references to LRU folios. */ lru_add_drain(); - if (page_count(page) > 1 + PageSwapCache(page)) + if (folio_ref_count(folio) > 1 + folio_test_swapcache(folio)) goto copy; - if (!trylock_page(page)) + if (!folio_trylock(folio)) goto copy; - if (PageSwapCache(page)) - try_to_free_swap(page); - if (PageKsm(page) || page_count(page) != 1) { - unlock_page(page); + if (folio_test_swapcache(folio)) + folio_free_swap(folio); + if (folio_test_ksm(folio) || folio_ref_count(folio) != 1) { + folio_unlock(folio); goto copy; } /* - * Ok, we've got the only page reference from our mapping - * and the page is locked, it's dark out, and we're wearing + * Ok, we've got the only folio reference from our mapping + * and the folio is locked, it's dark out, and we're wearing * sunglasses. Hit it. */ - page_move_anon_rmap(page, vma); - unlock_page(page); + page_move_anon_rmap(vmf->page, vma); + folio_unlock(folio); reuse: if (unlikely(unshare)) { pte_unmap_unlock(vmf->pte, vmf->ptl); -- 2.7.4