Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278AbbEAFnz (ORCPT ); Fri, 1 May 2015 01:43:55 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:41859 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752939AbbEAFny (ORCPT ); Fri, 1 May 2015 01:43:54 -0400 From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, mpe@ellerman.id.au, paulus@samba.org, benh@kernel.crashing.org, kirill.shutemov@linux.intel.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [PATCH V2 1/2] mm/thp: Use new functions to clear pmd on splitting and collapse Date: Fri, 1 May 2015 11:13:25 +0530 Message-Id: <1430459006-18142-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430459006-18142-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1430459006-18142-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15050105-0025-0000-0000-0000048A64C8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2916 Lines: 88 Some arch may require an explicit IPI before a THP PMD split or collapse. This enable us to use local_irq_disable to prevent a parallel THP PMD split or collapse. Signed-off-by: Aneesh Kumar K.V --- include/asm-generic/pgtable.h | 32 ++++++++++++++++++++++++++++++++ mm/huge_memory.c | 9 +++++---- 2 files changed, 37 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index fe617b7e4be6..e95c697bef25 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -184,6 +184,38 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif +#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH_NOTIFY +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#define pmdp_splitting_flush_notify pmdp_clear_flush_notify +#else +static inline void pmdp_splitting_flush_notify(struct vm_area_struct *vma, + unsigned long address, + pmd_t *pmdp) +{ + BUILD_BUG(); +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif + +#ifndef __HAVE_ARCH_PMDP_COLLAPSE_FLUSH +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, + unsigned long address, + pmd_t *pmdp) +{ + return pmdp_clear_flush(vma, address, pmdp); +} +#else +static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, + unsigned long address, + pmd_t *pmdp) +{ + BUILD_BUG(); + return __pmd(0); +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif + #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, pgtable_t pgtable); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cce4604c192f..30c1b46fcf6d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2187,7 +2187,7 @@ static void collapse_huge_page(struct mm_struct *mm, * huge and small TLB entries for the same virtual address * to avoid the risk of CPU bugs in that area. */ - _pmd = pmdp_clear_flush(vma, address, pmd); + _pmd = pmdp_collapse_flush(vma, address, pmd); spin_unlock(pmd_ptl); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); @@ -2606,9 +2606,10 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, write = pmd_write(*pmd); young = pmd_young(*pmd); - - /* leave pmd empty until pte is filled */ - pmdp_clear_flush_notify(vma, haddr, pmd); + /* + * leave pmd empty until pte is filled. + */ + pmdp_splitting_flush_notify(vma, haddr, pmd); pgtable = pgtable_trans_huge_withdraw(mm, pmd); pmd_populate(mm, &_pmd, pgtable); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/