From 8dc4a8f1e038189cb575f89bcd23364698b88cc1 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Wed, 16 Aug 2023 16:11:52 +0100 Subject: mm: convert free_transhuge_folio() to folio_undo_large_rmappable() Indirect calls are expensive, thanks to Spectre. Test for TRANSHUGE_PAGE_DTOR and destroy the folio appropriately. Move the free_compound_page() call into destroy_large_folio() to simplify later patches. Link: https://lkml.kernel.org/r/20230816151201.3655946-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: David Hildenbrand Cc: Jens Axboe Cc: Sidhartha Kumar Cc: Yanteng Si Signed-off-by: Andrew Morton --- mm/huge_memory.c | 22 +++++++++++----------- mm/internal.h | 2 ++ mm/page_alloc.c | 9 ++++++--- 3 files changed, 19 insertions(+), 14 deletions(-) (limited to 'mm') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 154c210892a1..b33456683b93 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2776,10 +2776,9 @@ out: return ret; } -void free_transhuge_page(struct page *page) +void folio_undo_large_rmappable(struct folio *folio) { - struct folio *folio = (struct folio *)page; - struct deferred_split *ds_queue = get_deferred_split_queue(folio); + struct deferred_split *ds_queue; unsigned long flags; /* @@ -2787,15 +2786,16 @@ void free_transhuge_page(struct page *page) * deferred_list. If folio is not in deferred_list, it's safe * to check without acquiring the split_queue_lock. */ - if (data_race(!list_empty(&folio->_deferred_list))) { - spin_lock_irqsave(&ds_queue->split_queue_lock, flags); - if (!list_empty(&folio->_deferred_list)) { - ds_queue->split_queue_len--; - list_del(&folio->_deferred_list); - } - spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); + if (data_race(list_empty(&folio->_deferred_list))) + return; + + ds_queue = get_deferred_split_queue(folio); + spin_lock_irqsave(&ds_queue->split_queue_lock, flags); + if (!list_empty(&folio->_deferred_list)) { + ds_queue->split_queue_len--; + list_del(&folio->_deferred_list); } - free_compound_page(page); + spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); } void deferred_split_folio(struct folio *folio) diff --git a/mm/internal.h b/mm/internal.h index d99ffb473f90..30bbfcacc909 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -413,6 +413,8 @@ static inline void folio_set_order(struct folio *folio, unsigned int order) #endif } +void folio_undo_large_rmappable(struct folio *folio); + static inline void prep_compound_head(struct page *page, unsigned int order) { struct folio *folio = (struct folio *)page; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 30dc444436cc..4047b5897443 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -287,9 +287,6 @@ const char * const migratetype_names[MIGRATE_TYPES] = { static compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = { [NULL_COMPOUND_DTOR] = NULL, [COMPOUND_PAGE_DTOR] = free_compound_page, -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - [TRANSHUGE_PAGE_DTOR] = free_transhuge_page, -#endif }; int min_free_kbytes = 1024; @@ -614,6 +611,12 @@ void destroy_large_folio(struct folio *folio) return; } + if (folio_test_transhuge(folio) && dtor == TRANSHUGE_PAGE_DTOR) { + folio_undo_large_rmappable(folio); + free_compound_page(&folio->page); + return; + } + VM_BUG_ON_FOLIO(dtor >= NR_COMPOUND_DTORS, folio); compound_page_dtors[dtor](&folio->page); } -- cgit v1.2.3