From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx203.postini.com [74.125.245.203]) by kanga.kvack.org (Postfix) with SMTP id F2BD86B0044 for ; Fri, 12 Oct 2012 01:00:52 -0400 (EDT) Received: by mail-da0-f41.google.com with SMTP id i14so1298341dad.14 for ; Thu, 11 Oct 2012 22:00:52 -0700 (PDT) Message-ID: <5077A3F7.6010407@gmail.com> Date: Fri, 12 Oct 2012 13:00:39 +0800 From: Ni zhan Chen MIME-Version: 1.0 Subject: Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page References: <1349191172-28855-1-git-send-email-kirill.shutemov@linux.intel.com> <1349191172-28855-8-git-send-email-kirill.shutemov@linux.intel.com> <50778D39.1000102@gmail.com> <20121012041305.GA16854@shutemov.name> In-Reply-To: <20121012041305.GA16854@shutemov.name> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, Andrea Arcangeli , Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org On 10/12/2012 12:13 PM, Kirill A. Shutemov wrote: > On Fri, Oct 12, 2012 at 11:23:37AM +0800, Ni zhan Chen wrote: >> On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote: >>> From: "Kirill A. Shutemov" >>> >>> We can't split huge zero page itself, but we can split the pmd which >>> points to it. >>> >>> On splitting the pmd we create a table with all ptes set to normal zero >>> page. >>> >>> Signed-off-by: Kirill A. Shutemov >>> Reviewed-by: Andrea Arcangeli >>> --- >>> mm/huge_memory.c | 32 ++++++++++++++++++++++++++++++++ >>> 1 files changed, 32 insertions(+), 0 deletions(-) >>> >>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>> index 95032d3..3f1c59c 100644 >>> --- a/mm/huge_memory.c >>> +++ b/mm/huge_memory.c >>> @@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page) >>> struct anon_vma *anon_vma; >>> int ret = 1; >>> + BUG_ON(is_huge_zero_pfn(page_to_pfn(page))); >>> BUG_ON(!PageAnon(page)); >>> anon_vma = page_lock_anon_vma(page); >>> if (!anon_vma) >>> @@ -2503,6 +2504,32 @@ static int khugepaged(void *none) >>> return 0; >>> } >>> +static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, >>> + unsigned long haddr, pmd_t *pmd) >>> +{ >>> + pgtable_t pgtable; >>> + pmd_t _pmd; >>> + int i; >>> + >>> + pmdp_clear_flush_notify(vma, haddr, pmd); >> why I can't find function pmdp_clear_flush_notify in kernel source >> code? Do you mean pmdp_clear_flush_young_notify or something like >> that? > It was changed recently. See commit > 2ec74c3 mm: move all mmu notifier invocations to be done outside the PT lock Oh, thanks! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org