mm: convert to should_zap_page() to should_zap_folio()

Make should_zap_page() take a folio and rename it to should_zap_folio() as
preparation for converting mm counter functions to take a folio.  Saves a
call to compound_head() hidden inside PageAnon().

[wangkefeng.wang@huawei.com: fix used-uninitialized warning]
Link: https://lkml.kernel.org/r/962a7993-fce9-4de8-85cd-25e290f25736@huawei.com
Link: https://lkml.kernel.org/r/20240111152429.3374566-9-willy@infradead.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index c8dd249419142cddba5cb5babb86c9c7463c084a..4bed82009ea7e0b1554e580e3bf0a015dcf472df 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1369,19 +1369,20 @@ static inline bool should_zap_cows(struct zap_details *details)
        return details->even_cows;
 }
 
-/* Decides whether we should zap this page with the page pointer specified */
-static inline bool should_zap_page(struct zap_details *details, struct page *page)
+/* Decides whether we should zap this folio with the folio pointer specified */
+static inline bool should_zap_folio(struct zap_details *details,
+                                   struct folio *folio)
 {
-       /* If we can make a decision without *page.. */
+       /* If we can make a decision without *folio.. */
        if (should_zap_cows(details))
                return true;
 
-       /* E.g. the caller passes NULL for the case of a zero page */
-       if (!page)
+       /* E.g. the caller passes NULL for the case of a zero folio */
+       if (!folio)
                return true;
 
-       /* Otherwise we should only zap non-anon pages */
-       return !PageAnon(page);
+       /* Otherwise we should only zap non-anon folios */
+       return !folio_test_anon(folio);
 }
 
 static inline bool zap_drop_file_uffd_wp(struct zap_details *details)
@@ -1434,7 +1435,7 @@ 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 folio *folio = NULL;
                struct page *page;
 
                if (pte_none(ptent))
@@ -1447,7 +1448,10 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                        unsigned int delay_rmap;
 
                        page = vm_normal_page(vma, addr, ptent);
-                       if (unlikely(!should_zap_page(details, page)))
+                       if (page)
+                               folio = page_folio(page);
+
+                       if (unlikely(!should_zap_folio(details, folio)))
                                continue;
                        ptent = ptep_get_and_clear_full(mm, addr, pte,
                                                        tlb->fullmm);
@@ -1460,7 +1464,6 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                                continue;
                        }
 
-                       folio = page_folio(page);
                        delay_rmap = 0;
                        if (!folio_test_anon(folio)) {
                                if (pte_dirty(ptent)) {
@@ -1492,7 +1495,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                    is_device_exclusive_entry(entry)) {
                        page = pfn_swap_entry_to_page(entry);
                        folio = page_folio(page);
-                       if (unlikely(!should_zap_page(details, page)))
+                       if (unlikely(!should_zap_folio(details, folio)))
                                continue;
                        /*
                         * Both device private/exclusive mappings should only
@@ -1513,10 +1516,10 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                        if (unlikely(!free_swap_and_cache(entry)))
                                print_bad_pte(vma, addr, ptent, NULL);
                } else if (is_migration_entry(entry)) {
-                       page = pfn_swap_entry_to_page(entry);
-                       if (!should_zap_page(details, page))
+                       folio = pfn_swap_entry_folio(entry);
+                       if (!should_zap_folio(details, folio))
                                continue;
-                       rss[mm_counter(page)]--;
+                       rss[mm_counter(&folio->page)]--;
                } else if (pte_marker_entry_uffd_wp(entry)) {
                        /*
                         * For anon: always drop the marker; for file: only