From e3ebcf64381188a2744a9829a4eb5c2b60f1974c Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Mon, 8 Oct 2012 16:30:07 -0700 Subject: thp: remove assumptions on pgtable_t type The thp page table pre-allocation code currently assumes that pgtable_t is of type "struct page *". This may not be true for all architectures, so this patch removes that assumption by replacing the functions prepare_pmd_huge_pte() and get_pmd_huge_pte() with two new functions that can be defined architecture-specific. It also removes two VM_BUG_ON checks for page_count() and page_mapcount() operating on a pgtable_t. Apart from the VM_BUG_ON removal, there will be no functional change introduced by this patch. Signed-off-by: Gerald Schaefer Cc: Andrea Arcangeli Cc: Andi Kleen Cc: Hugh Dickins Cc: Hillf Danton Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/pgtable-generic.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'mm/pgtable-generic.c') diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index 74c0ddaa6fa0..29867e083d37 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -120,3 +120,42 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif + +#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable) +{ + assert_spin_locked(&mm->page_table_lock); + + /* FIFO */ + if (!mm->pmd_huge_pte) + INIT_LIST_HEAD(&pgtable->lru); + else + list_add(&pgtable->lru, &mm->pmd_huge_pte->lru); + mm->pmd_huge_pte = pgtable; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif + +#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +/* no "address" argument so destroys page coloring of some arch */ +pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm) +{ + pgtable_t pgtable; + + assert_spin_locked(&mm->page_table_lock); + + /* FIFO */ + pgtable = mm->pmd_huge_pte; + if (list_empty(&pgtable->lru)) + mm->pmd_huge_pte = NULL; + else { + mm->pmd_huge_pte = list_entry(pgtable->lru.next, + struct page, lru); + list_del(&pgtable->lru); + } + return pgtable; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif -- cgit v1.2.3