From 9501d09fa3c4ca18971083dfb0c9aa1afc85f19c Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Mon, 8 Oct 2012 16:30:18 -0700 Subject: [PATCH] thp, s390: thp pagetable pre-allocation for s390 This patch is part of the architecture backend for thp on s390. It provides the pagetable pre-allocation functions pgtable_trans_huge_deposit() and pgtable_trans_huge_withdraw(). Unlike other archs, s390 has no struct page * as pgtable_t, but rather a pointer to the page table. So instead of saving the pagetable pre- allocation list info inside the struct page, it is being saved within the pagetable itself. 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 --- arch/s390/include/asm/pgtable.h | 6 ++++++ arch/s390/mm/pgtable.c | 38 +++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index c3f0775e71f1..2c8f00d31cfe 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1166,6 +1166,12 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) #define pte_unmap(pte) do { } while (0) #ifdef CONFIG_TRANSPARENT_HUGEPAGE +#define __HAVE_ARCH_PGTABLE_DEPOSIT +extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable); + +#define __HAVE_ARCH_PGTABLE_WITHDRAW +extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm); + static inline int pmd_trans_splitting(pmd_t pmd) { return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT; diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index a6131d1fe6c0..1ca371a06516 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -883,4 +883,42 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, smp_call_function(pmdp_splitting_flush_sync, NULL, 1); } } + +void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable) +{ + struct list_head *lh = (struct list_head *) pgtable; + + assert_spin_locked(&mm->page_table_lock); + + /* FIFO */ + if (!mm->pmd_huge_pte) + INIT_LIST_HEAD(lh); + else + list_add(lh, (struct list_head *) mm->pmd_huge_pte); + mm->pmd_huge_pte = pgtable; +} + +pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm) +{ + struct list_head *lh; + pgtable_t pgtable; + pte_t *ptep; + + assert_spin_locked(&mm->page_table_lock); + + /* FIFO */ + pgtable = mm->pmd_huge_pte; + lh = (struct list_head *) pgtable; + if (list_empty(lh)) + mm->pmd_huge_pte = NULL; + else { + mm->pmd_huge_pte = (pgtable_t) lh->next; + list_del(lh); + } + ptep = (pte_t *) pgtable; + pte_val(*ptep) = _PAGE_TYPE_EMPTY; + ptep++; + pte_val(*ptep) = _PAGE_TYPE_EMPTY; + return pgtable; +} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -- 2.20.1