From b26c65bedbff4012fcaf9e2aa47281fd9aed0ec3 Mon Sep 17 00:00:00 2001 From: Zi Yan Date: Sun, 20 Sep 2026 22:28:13 -0400 Subject: [PATCH] mm/page-flags: remove PG_private folio->private != NULL indicates a folio carries private data, replacing PG_private. All PG_private users are converted. Remove PG_private and reserve the space as PG_folio for future use. Unused PG_private functions are removed too. Link: https://lore.kernel.org/20260920-remove-pg_private-v5-17-bb68b6a21869@nvidia.com Signed-off-by: Zi Yan Signed-off-by: Andrew Morton Acked-by: David Hildenbrand (Arm) Assisted-by: LLM Cc: Baoquan He Cc: Mike Rapoport Cc: Pasha Tatashin Cc: Pratyush Yadav Cc: Jonathan Corbet Cc: "Matthew Wilcox (Oracle)" Cc: Jan Kara Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Dave Young Cc: Shuah Khan Cc: Lorenzo Stoakes Cc: "Liam R. Howlett" Cc: Vlastimil Babka Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Mathieu Desnoyers --- include/linux/page-flags.h | 18 +----------------- include/trace/events/mmflags.h | 2 +- kernel/vmcore_info.c | 1 - 3 files changed, 2 insertions(+), 19 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 6d839f50bdcb..b0ddc652e76c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -44,10 +44,6 @@ * Consequently, PG_reserved for a page mapped into user space can indicate * the zero page, the vDSO, MMIO pages or device memory. * - * The PG_private bitflag is set on pagecache pages if they contain filesystem - * specific data (which is normally at page->private). It can be used by - * private allocations for its own usage. - * * During initiation of disk I/O, PG_locked is set. This bit is set before I/O * and cleared when writeback _starts_ or when read _completes_. PG_writeback * is set before writeback starts and cleared when it finishes. @@ -105,7 +101,7 @@ enum pageflags { PG_owner_2, /* Owner use. If pagecache, fs may use */ PG_arch_1, PG_reserved, - PG_private, /* If pagecache, has fs-private data */ + PG_folio, /* Do not use: reserved for folio identification */ PG_private_2, /* If pagecache, has fs aux data */ PG_reclaim, /* To be reclaimed asap */ PG_swapbacked, /* Page is backed by RAM/swap */ @@ -588,18 +584,6 @@ static __always_inline bool folio_test_private(const struct folio *folio) return data_race(folio->private); } -static __always_inline int PagePrivate(const struct page *page) -{ - /* See folio_test_private() for data_race() use */ - return !!data_race(page->private); -} - -/* no-ops during transition */ -static __always_inline void folio_set_private(struct folio *folio) { } -static __always_inline void folio_clear_private(struct folio *folio) { } -static __always_inline void SetPagePrivate(struct page *page) { } -static __always_inline void ClearPagePrivate(struct page *page) { } - FOLIO_FLAG(private_2, FOLIO_HEAD_PAGE) /* owner_2 can be set on tail pages for anon memory */ diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index ef9aa388b84f..3c153b3ad845 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -144,7 +144,7 @@ TRACE_DEFINE_ENUM(___GFP_LAST_BIT); DEF_PAGEFLAG_NAME(owner_2), \ DEF_PAGEFLAG_NAME(arch_1), \ DEF_PAGEFLAG_NAME(reserved), \ - DEF_PAGEFLAG_NAME(private), \ + DEF_PAGEFLAG_NAME(folio), \ DEF_PAGEFLAG_NAME(private_2), \ DEF_PAGEFLAG_NAME(writeback), \ DEF_PAGEFLAG_NAME(head), \ diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c index 8614430ca212..5a417f8a922a 100644 --- a/kernel/vmcore_info.c +++ b/kernel/vmcore_info.c @@ -216,7 +216,6 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); VMCOREINFO_NUMBER(NR_FREE_PAGES); VMCOREINFO_NUMBER(PG_lru); - VMCOREINFO_NUMBER(PG_private); VMCOREINFO_NUMBER(PG_swapcache); VMCOREINFO_NUMBER(PG_swapbacked); #define PAGE_SLAB_MAPCOUNT_VALUE (PGTY_slab << 24)