From 5f32b265400de723ab0db23101a75ac073bdd980 Mon Sep 17 00:00:00 2001 From: Jérôme Glisse Date: Thu, 31 Aug 2017 17:17:38 -0400 Subject: mm/mmu_notifier: kill invalidate_page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The invalidate_page callback suffered from two pitfalls. First it used to happen after the page table lock was release and thus a new page might have setup before the call to invalidate_page() happened. This is in a weird way fixed by commit c7ab0d2fdc84 ("mm: convert try_to_unmap_one() to use page_vma_mapped_walk()") that moved the callback under the page table lock but this also broke several existing users of the mmu_notifier API that assumed they could sleep inside this callback. The second pitfall was invalidate_page() being the only callback not taking a range of address in respect to invalidation but was giving an address and a page. Lots of the callback implementers assumed this could never be THP and thus failed to invalidate the appropriate range for THP. By killing this callback we unify the mmu_notifier callback API to always take a virtual address range as input. Finally this also simplifies the end user life as there is now two clear choices: - invalidate_range_start()/end() callback (which allow you to sleep) - invalidate_range() where you can not sleep but happen right after page table update under page table lock Signed-off-by: Jérôme Glisse Cc: Bernhard Held Cc: Adam Borowski Cc: Andrea Arcangeli Cc: Radim Krčmář Cc: Wanpeng Li Cc: Paolo Bonzini Cc: Takashi Iwai Cc: Nadav Amit Cc: Mike Galbraith Cc: Kirill A. Shutemov Cc: axie Cc: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmu_notifier.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'mm') diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 54ca54562928..314285284e6e 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -174,20 +174,6 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, srcu_read_unlock(&srcu, id); } -void __mmu_notifier_invalidate_page(struct mm_struct *mm, - unsigned long address) -{ - struct mmu_notifier *mn; - int id; - - id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { - if (mn->ops->invalidate_page) - mn->ops->invalidate_page(mn, mm, address); - } - srcu_read_unlock(&srcu, id); -} - void __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end) { -- cgit v1.2.3-59-g8ed1b