From 528815392f873f0af8c6cdc279c89bd0154cbf6a Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Wed, 26 Jun 2024 16:53:25 +0800 Subject: [PATCH] mm: migrate: split folio_migrate_mapping() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The folio refcount check is moved out for both !mapping and mapping folio, also update comment from page to folio for folio_migrate_mapping(). No functional change intended. Link: https://lkml.kernel.org/r/20240626085328.608006-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Cc: Alistair Popple Cc: Benjamin LaHaise Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jane Chu Cc: Jérôme Glisse Cc: Jiaqi Yan Cc: Lance Yang Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Muchun Song Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Tony Luck Cc: Vishal Moola (Oracle) Signed-off-by: Andrew Morton --- mm/migrate.c | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 9a1c5b4a3f99..13b032269242 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -393,28 +393,23 @@ static int folio_expected_refs(struct address_space *mapping, } /* - * Replace the page in the mapping. + * Replace the folio in the mapping. * * The number of remaining references must be: - * 1 for anonymous pages without a mapping - * 2 for pages with a mapping - * 3 for pages with a mapping and PagePrivate/PagePrivate2 set. + * 1 for anonymous folios without a mapping + * 2 for folios with a mapping + * 3 for folios with a mapping and PagePrivate/PagePrivate2 set. */ -int folio_migrate_mapping(struct address_space *mapping, - struct folio *newfolio, struct folio *folio, int extra_count) +static int __folio_migrate_mapping(struct address_space *mapping, + struct folio *newfolio, struct folio *folio, int expected_count) { XA_STATE(xas, &mapping->i_pages, folio_index(folio)); struct zone *oldzone, *newzone; int dirty; - int expected_count = folio_expected_refs(mapping, folio) + extra_count; long nr = folio_nr_pages(folio); long entries, i; if (!mapping) { - /* Anonymous page without mapping */ - if (folio_ref_count(folio) != expected_count) - return -EAGAIN; - /* Take off deferred split queue while frozen and memcg set */ if (folio_test_large(folio) && folio_test_large_rmappable(folio)) { @@ -465,7 +460,7 @@ int folio_migrate_mapping(struct address_space *mapping, entries = 1; } - /* Move dirty while page refs frozen and newpage not yet exposed */ + /* Move dirty while folio refs frozen and newfolio not yet exposed */ dirty = folio_test_dirty(folio); if (dirty) { folio_clear_dirty(folio); @@ -479,7 +474,7 @@ int folio_migrate_mapping(struct address_space *mapping, } /* - * Drop cache reference from old page by unfreezing + * Drop cache reference from old folio by unfreezing * to one less reference. * We know this isn't the last reference. */ @@ -490,11 +485,11 @@ int folio_migrate_mapping(struct address_space *mapping, /* * If moved to a different zone then also account - * the page for that zone. Other VM counters will be + * the folio for that zone. Other VM counters will be * taken care of when we establish references to the - * new page and drop references to the old page. + * new folio and drop references to the old folio. * - * Note that anonymous pages are accounted for + * Note that anonymous folios are accounted for * via NR_FILE_PAGES and NR_ANON_MAPPED if they * are mapped to swap space. */ @@ -534,6 +529,17 @@ int folio_migrate_mapping(struct address_space *mapping, return MIGRATEPAGE_SUCCESS; } + +int folio_migrate_mapping(struct address_space *mapping, + struct folio *newfolio, struct folio *folio, int extra_count) +{ + int expected_count = folio_expected_refs(mapping, folio) + extra_count; + + if (folio_ref_count(folio) != expected_count) + return -EAGAIN; + + return __folio_migrate_mapping(mapping, newfolio, folio, expected_count); +} EXPORT_SYMBOL(folio_migrate_mapping); /* -- 2.25.1