Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751870AbbD3QrS (ORCPT ); Thu, 30 Apr 2015 12:47:18 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:51307 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750866AbbD3QrO (ORCPT ); Thu, 30 Apr 2015 12:47:14 -0400 From: "Aneesh Kumar K.V" To: "Kirill A. Shutemov" Cc: akpm@linux-foundation.org, paulus@samba.org, benh@kernel.crashing.org, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 1/3] mm/thp: Use pmdp_splitting_flush_notify to clear pmd on splitting In-Reply-To: <87iocd38uj.fsf@linux.vnet.ibm.com> References: <1429823043-157133-1-git-send-email-kirill.shutemov@linux.intel.com> <1430382341-8316-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1430382341-8316-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20150430133035.GF15874@node.dhcp.inet.fi> <87iocd38uj.fsf@linux.vnet.ibm.com> User-Agent: Notmuch/0.19+103~g294bb6d (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Thu, 30 Apr 2015 22:17:04 +0530 Message-ID: <87fv7h36nr.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15043016-0009-0000-0000-00000526D7DF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3183 Lines: 95 "Aneesh Kumar K.V" writes: > "Kirill A. Shutemov" writes: > >>> @@ -184,3 +185,13 @@ void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, >>> } >>> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >>> #endif >>> + >>> +#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH_NOTIFY >>> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >>> +void pmdp_splitting_flush_notify(struct vm_area_struct *vma, >>> + unsigned long address, pmd_t *pmdp) >>> +{ >>> + pmdp_clear_flush_notify(vma, address, pmdp); >>> +} >>> +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ >>> +#endif >> >> I think it worth inlining. Let's put it to >> >> It probably worth combining with collapse counterpart in the same patch. >> > > I tried that first, But that pulls in mmu_notifier.h and huge_mm.h > headers and other build failures > Putting them in TRANSPATENT_HUGEPAGE helped. commit 9c60ab5d1d684db2ba454ee1c7f3e9a6bf57f026 Author: Aneesh Kumar K.V Date: Wed Apr 29 14:57:30 2015 +0530 mm/thp: Use pmdp_splitting_flush_notify to clear pmd on splitting Some arch may require an explicit IPI before a THP PMD split. This ensures that a local_irq_disable can prevent a parallel THP PMD split. So use new function which arch can override Signed-off-by: Aneesh Kumar K.V diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index fe617b7e4be6..6a0b2ab899d1 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -184,6 +184,24 @@ 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 +static inline void pmdp_splitting_flush_notify(struct vm_area_struct *vma, + unsigned long address, + pmd_t *pmdp) +{ + pmdp_clear_flush_notify(vma, address, pmdp); +} +#else +static inline void pmdp_splitting_flush_notify(struct vm_area_struct *vma, + unsigned long address, + pmd_t *pmdp) +{ + BUG(); +} +#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..81e9578bf43a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -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); -- 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/