diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 71 |
1 files changed, 42 insertions, 29 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 2490e727e2dc..a8797d1b3d49 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -75,6 +75,7 @@ #include <linux/memremap.h> #include <linux/userfaultfd_k.h> #include <linux/mm_inline.h> +#include <linux/oom.h> #include <asm/tlbflush.h> @@ -870,6 +871,20 @@ static bool folio_referenced_one(struct folio *folio, continue; } + /* + * Skip the non-shared swapbacked folio mapped solely by + * the exiting or OOM-reaped process. This avoids redundant + * swap-out followed by an immediate unmap. + */ + if ((!atomic_read(&vma->vm_mm->mm_users) || + check_stable_address_space(vma->vm_mm)) && + folio_test_anon(folio) && folio_test_swapbacked(folio) && + !folio_likely_mapped_shared(folio)) { + pra->referenced = -1; + page_vma_mapped_walk_done(&pvmw); + return false; + } + if (pvmw.pte) { if (lru_gen_enabled() && pte_young(ptep_get(pvmw.pte))) { @@ -1143,25 +1158,25 @@ static __always_inline unsigned int __folio_add_rmap(struct folio *folio, { atomic_t *mapped = &folio->_nr_pages_mapped; const int orig_nr_pages = nr_pages; - int first, nr = 0; + int first = 0, nr = 0; __folio_rmap_sanity_checks(folio, page, nr_pages, level); switch (level) { case RMAP_LEVEL_PTE: if (!folio_test_large(folio)) { - nr = atomic_inc_and_test(&page->_mapcount); + nr = atomic_inc_and_test(&folio->_mapcount); break; } do { - first = atomic_inc_and_test(&page->_mapcount); - if (first) { - first = atomic_inc_return_relaxed(mapped); - if (first < ENTIRELY_MAPPED) - nr++; - } + first += atomic_inc_and_test(&page->_mapcount); } while (page++, --nr_pages > 0); + + if (first && + atomic_add_return_relaxed(first, mapped) < ENTIRELY_MAPPED) + nr = first; + atomic_add(orig_nr_pages, &folio->_large_mapcount); break; case RMAP_LEVEL_PMD: @@ -1452,6 +1467,7 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, } __folio_mod_stat(folio, nr, nr_pmdmapped); + mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); } static __always_inline void __folio_add_file_rmap(struct folio *folio, @@ -1512,7 +1528,7 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, enum rmap_level level) { atomic_t *mapped = &folio->_nr_pages_mapped; - int last, nr = 0, nr_pmdmapped = 0; + int last = 0, nr = 0, nr_pmdmapped = 0; bool partially_mapped = false; __folio_rmap_sanity_checks(folio, page, nr_pages, level); @@ -1520,20 +1536,19 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, switch (level) { case RMAP_LEVEL_PTE: if (!folio_test_large(folio)) { - nr = atomic_add_negative(-1, &page->_mapcount); + nr = atomic_add_negative(-1, &folio->_mapcount); break; } atomic_sub(nr_pages, &folio->_large_mapcount); do { - last = atomic_add_negative(-1, &page->_mapcount); - if (last) { - last = atomic_dec_return_relaxed(mapped); - if (last < ENTIRELY_MAPPED) - nr++; - } + last += atomic_add_negative(-1, &page->_mapcount); } while (page++, --nr_pages > 0); + if (last && + atomic_sub_return_relaxed(last, mapped) < ENTIRELY_MAPPED) + nr = last; + partially_mapped = nr && atomic_read(mapped); break; case RMAP_LEVEL_PMD: @@ -1553,22 +1568,20 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, } } - partially_mapped = nr < nr_pmdmapped; + partially_mapped = nr && nr < nr_pmdmapped; break; } - if (nr) { - /* - * Queue anon large folio for deferred split if at least one - * page of the folio is unmapped and at least one page - * is still mapped. - * - * Check partially_mapped first to ensure it is a large folio. - */ - if (folio_test_anon(folio) && partially_mapped && - list_empty(&folio->_deferred_list)) - deferred_split_folio(folio); - } + /* + * Queue anon large folio for deferred split if at least one page of + * the folio is unmapped and at least one page is still mapped. + * + * Check partially_mapped first to ensure it is a large folio. + */ + if (partially_mapped && folio_test_anon(folio) && + !folio_test_partially_mapped(folio)) + deferred_split_folio(folio, true); + __folio_mod_stat(folio, -nr, -nr_pmdmapped); /* |