The huge-PMD and PTE paths duplicate folio filtering, reference clearing, deactivation and pageout isolation. Keeping both copies synchronized obscures the page-table-specific control flow.
Factor the common filtering and LRU operation into helpers. Keep the lock-before-reference sequence visible at each split site because an early reference can prevent split_folio() from succeeding. No functional change intended. Assisted-by: LLM Signed-off-by: Gregory Price (Meta) <[email protected]> --- mm/madvise.c | 90 +++++++++++++++++++++++++--------------------------- 1 file changed, 43 insertions(+), 47 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 83d54ab385da8..c345fef23f15d 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -361,6 +361,39 @@ static inline int madvise_folio_pte_batch(unsigned long addr, unsigned long end, FPB_MERGE_YOUNG_DIRTY); } +static inline void +madvise_lru_folio(struct folio *folio, bool pageout, + struct list_head *folio_list) +{ + /* + * Clear references before deactivating or reclaiming the folio. This can + * make idle-page tracking miss recent accesses. + */ + folio_clear_referenced(folio); + folio_test_clear_young(folio); + if (folio_test_active(folio)) + folio_set_workingset(folio); + + if (!pageout) { + folio_deactivate(folio); + return; + } + + if (!folio_isolate_lru(folio)) + return; + if (folio_test_unevictable(folio)) + folio_putback_lru(folio); + else + list_add(&folio->lru, folio_list); +} + +static bool madvise_lru_folio_is_filtered(struct folio *folio, + bool pageout_anon_only) +{ + return folio_maybe_mapped_shared(folio) || + (pageout_anon_only && !folio_test_anon(folio)); +} + static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { @@ -373,15 +406,14 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, spinlock_t *ptl; struct folio *folio = NULL; LIST_HEAD(folio_list); - bool pageout_anon_only_filter; unsigned int batch_count = 0; + bool pageout_anon_only; int nr; if (fatal_signal_pending(current)) return -EINTR; - - pageout_anon_only_filter = pageout && !vma_is_anonymous(vma) && - !can_do_file_pageout(vma); + pageout_anon_only = pageout && !vma_is_anonymous(vma) && + !can_do_file_pageout(vma); #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (pmd_trans_huge(*pmd)) { @@ -407,11 +439,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, if (folio_is_zone_device(folio)) goto huge_unlock; - /* Do not interfere with other mappings of this folio */ - if (folio_maybe_mapped_shared(folio)) - goto huge_unlock; - - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (madvise_lru_folio_is_filtered(folio, pageout_anon_only)) goto huge_unlock; if (next - addr != HPAGE_PMD_SIZE) { @@ -437,19 +465,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, tlb_remove_pmd_tlb_entry(tlb, pmd, addr); } - folio_clear_referenced(folio); - folio_test_clear_young(folio); - if (folio_test_active(folio)) - folio_set_workingset(folio); - if (pageout) { - if (folio_isolate_lru(folio)) { - if (folio_test_unevictable(folio)) - folio_putback_lru(folio); - else - list_add(&folio->lru, &folio_list); - } - } else - folio_deactivate(folio); + madvise_lru_folio(folio, pageout, &folio_list); huge_unlock: spin_unlock(ptl); if (pageout) @@ -502,9 +518,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, if (nr < folio_nr_pages(folio)) { int err; - if (folio_maybe_mapped_shared(folio)) - continue; - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (madvise_lru_folio_is_filtered(folio, pageout_anon_only)) continue; if (!folio_trylock(folio)) continue; @@ -537,7 +551,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, folio_mapcount(folio) != folio_nr_pages(folio)) continue; - if (pageout_anon_only_filter && !folio_test_anon(folio)) + if (pageout_anon_only && !folio_test_anon(folio)) continue; if (!pageout && pte_young(ptent)) { @@ -546,25 +560,7 @@ static int madvise_lru_pmd_entry(pmd_t *pmd, unsigned long addr, tlb_remove_tlb_entries(tlb, pte, nr, addr); } - /* - * We are deactivating a folio for accelerating reclaiming. - * VM couldn't reclaim the folio unless we clear PG_young. - * As a side effect, it makes confuse idle-page tracking - * because they will miss recent referenced history. - */ - folio_clear_referenced(folio); - folio_test_clear_young(folio); - if (folio_test_active(folio)) - folio_set_workingset(folio); - if (pageout) { - if (folio_isolate_lru(folio)) { - if (folio_test_unevictable(folio)) - folio_putback_lru(folio); - else - list_add(&folio->lru, &folio_list); - } - } else - folio_deactivate(folio); + madvise_lru_folio(folio, pageout, &folio_list); } out: @@ -651,8 +647,8 @@ static long madvise_pageout(struct madvise_behavior *madv_behavior) * owner nor write capable of the file. We allow private file mappings * further to pageout dirty anon pages. */ - if (!vma_is_anonymous(vma) && (!can_do_file_pageout(vma) && - (vma->vm_flags & VM_MAYSHARE))) + if (!vma_is_anonymous(vma) && !can_do_file_pageout(vma) && + (vma->vm_flags & VM_MAYSHARE)) return 0; lru_add_drain(); -- 2.53.0-Meta
