From fcbe08d66f57c368e77ca729dd01e6b539ffb3ff Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 24 Oct 2014 10:52:29 +0200 Subject: [PATCH] s390/mm: pmdp_get_and_clear_full optimization Analog to ptep_get_and_clear_full define a variant of the pmpd_get_and_clear primitive which gets the full hint from the mmu_gather struct. This allows s390 to avoid a costly instruction when destroying an address space. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 13 +++++++++++++ include/asm-generic/pgtable.h | 11 +++++++++++ mm/huge_memory.c | 3 ++- 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 5ef1a266936a..5e102422c9ab 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1651,6 +1651,19 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, return pmd; } +#define __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL +static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm, + unsigned long address, + pmd_t *pmdp, int full) +{ + pmd_t pmd = *pmdp; + + if (!full) + pmdp_flush_lazy(mm, address, pmdp); + pmd_clear(pmdp); + return pmd; +} + #define __HAVE_ARCH_PMDP_CLEAR_FLUSH static inline pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 752e30d63904..177d5973b132 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -103,6 +103,17 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif +#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR_FULL +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t pmdp_get_and_clear_full(struct mm_struct *mm, + unsigned long address, pmd_t *pmdp, + int full) +{ + return pmdp_get_and_clear(mm, address, pmdp); +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif + #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long address, pte_t *ptep, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 7e9c15cb93a9..6a37f1b2ed1e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1400,7 +1400,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, * pgtable_trans_huge_withdraw after finishing pmdp related * operations. */ - orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd); + orig_pmd = pmdp_get_and_clear_full(tlb->mm, addr, pmd, + tlb->fullmm); tlb_remove_pmd_tlb_entry(tlb, pmd, addr); pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); if (is_huge_zero_pmd(orig_pmd)) {