From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754517AbbFCRTp (ORCPT ); Wed, 3 Jun 2015 13:19:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:46992 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933154AbbFCRGa (ORCPT ); Wed, 3 Jun 2015 13:06:30 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,548,1427785200"; d="scan'208";a="720166491" From: "Kirill A. Shutemov" To: Andrew Morton , Andrea Arcangeli , Hugh Dickins Cc: Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv6 20/36] powerpc, thp: remove infrastructure for handling splitting PMDs Date: Wed, 3 Jun 2015 20:05:51 +0300 Message-Id: <1433351167-125878-21-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With new refcounting we don't need to mark PMDs splitting. Let's drop code to handle this. pmdp_splitting_flush() is not needed too: on splitting PMD we will do pmdp_clear_flush() + set_pte_at(). pmdp_clear_flush() will do IPI as needed for fast_gup. Signed-off-by: Kirill A. Shutemov --- arch/powerpc/include/asm/kvm_book3s_64.h | 6 ---- arch/powerpc/include/asm/pgtable-ppc64.h | 25 +--------------- arch/powerpc/mm/hugepage-hash64.c | 3 -- arch/powerpc/mm/hugetlbpage.c | 7 +---- arch/powerpc/mm/pgtable_64.c | 49 -------------------------------- 5 files changed, 2 insertions(+), 88 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index 2d81e202bdcc..9a96fe3caa48 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -298,12 +298,6 @@ static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing, cpu_relax(); continue; } -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - /* If hugepage and is trans splitting return None */ - if (unlikely(hugepage && - pmd_trans_splitting(pte_pmd(old_pte)))) - return __pte(0); -#endif /* If pte is not present return None */ if (unlikely(!(old_pte & _PAGE_PRESENT))) return __pte(0); diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index 012e3adab7f8..5729b303d206 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -358,11 +358,6 @@ void pgtable_cache_init(void); #endif /* __ASSEMBLY__ */ /* - * THP pages can't be special. So use the _PAGE_SPECIAL - */ -#define _PAGE_SPLITTING _PAGE_SPECIAL - -/* * We need to differentiate between explicit huge page and THP huge * page, since THP huge page also need to track real subpage details */ @@ -372,8 +367,7 @@ void pgtable_cache_init(void); * set of bits not changed in pmd_modify. */ #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | \ - _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \ - _PAGE_THP_HUGE) + _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_THP_HUGE) #ifndef __ASSEMBLY__ /* @@ -455,13 +449,6 @@ static inline int pmd_trans_huge(pmd_t pmd) return (pmd_val(pmd) & 0x3) && (pmd_val(pmd) & _PAGE_THP_HUGE); } -static inline int pmd_trans_splitting(pmd_t pmd) -{ - if (pmd_trans_huge(pmd)) - return pmd_val(pmd) & _PAGE_SPLITTING; - return 0; -} - extern int has_transparent_hugepage(void); #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -514,12 +501,6 @@ static inline pmd_t pmd_mknotpresent(pmd_t pmd) return pmd; } -static inline pmd_t pmd_mksplitting(pmd_t pmd) -{ - pmd_val(pmd) |= _PAGE_SPLITTING; - return pmd; -} - #define __HAVE_ARCH_PMD_SAME static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) { @@ -570,10 +551,6 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr, pmd_hugepage_update(mm, addr, pmdp, _PAGE_RW, 0); } -#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH -extern void pmdp_splitting_flush(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp); - #define pmdp_collapse_flush pmdp_collapse_flush extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c index 86686514ae13..078f7207afd2 100644 --- a/arch/powerpc/mm/hugepage-hash64.c +++ b/arch/powerpc/mm/hugepage-hash64.c @@ -39,9 +39,6 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid, /* If PMD busy, retry the access */ if (unlikely(old_pmd & _PAGE_BUSY)) return 0; - /* If PMD is trans splitting retry the access */ - if (unlikely(old_pmd & _PAGE_SPLITTING)) - return 0; /* If PMD permissions don't match, take page fault */ if (unlikely(access & ~old_pmd)) return 1; diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 5f979e51ef7b..a09ff52b906e 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -997,13 +997,8 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift /* * A hugepage collapse is captured by pmd_none, because * it mark the pmd none and do a hpte invalidate. - * - * A hugepage split is captured by pmd_trans_splitting - * because we mark the pmd trans splitting and do a - * hpte invalidate - * */ - if (pmd_none(pmd) || pmd_trans_splitting(pmd)) + if (pmd_none(pmd)) return NULL; if (pmd_huge(pmd) || pmd_large(pmd)) { diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 52c4827bceb0..7bad475bc235 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -614,55 +614,6 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, } /* - * We mark the pmd splitting and invalidate all the hpte - * entries for this hugepage. - */ -void pmdp_splitting_flush(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp) -{ - unsigned long old, tmp; - - VM_BUG_ON(address & ~HPAGE_PMD_MASK); - -#ifdef CONFIG_DEBUG_VM - WARN_ON(!pmd_trans_huge(*pmdp)); - assert_spin_locked(&vma->vm_mm->page_table_lock); -#endif - -#ifdef PTE_ATOMIC_UPDATES - - __asm__ __volatile__( - "1: ldarx %0,0,%3\n\ - andi. %1,%0,%6\n\ - bne- 1b \n\ - ori %1,%0,%4 \n\ - stdcx. %1,0,%3 \n\ - bne- 1b" - : "=&r" (old), "=&r" (tmp), "=m" (*pmdp) - : "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY) - : "cc" ); -#else - old = pmd_val(*pmdp); - *pmdp = __pmd(old | _PAGE_SPLITTING); -#endif - /* - * If we didn't had the splitting flag set, go and flush the - * HPTE entries. - */ - trace_hugepage_splitting(address, old); - if (!(old & _PAGE_SPLITTING)) { - /* We need to flush the hpte */ - if (old & _PAGE_HASHPTE) - hpte_do_hugepage_flush(vma->vm_mm, address, pmdp, old); - } - /* - * This ensures that generic code that rely on IRQ disabling - * to prevent a parallel THP split work as expected. - */ - kick_all_cpus_sync(); -} - -/* * We want to put the pgtable in pmd and use pgtable for tracking * the base page size hptes */ -- 2.1.4