From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx170.postini.com [74.125.245.170]) by kanga.kvack.org (Postfix) with SMTP id 0E6916B0044 for ; Fri, 12 Oct 2012 00:12:13 -0400 (EDT) Date: Fri, 12 Oct 2012 07:13:05 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page Message-ID: <20121012041305.GA16854@shutemov.name> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50778D39.1000102@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ni zhan Chen Cc: "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, Andrea Arcangeli , Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org 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 -- Kirill A. Shutemov -- 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