Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752703AbbHCKxb (ORCPT ); Mon, 3 Aug 2015 06:53:31 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:32932 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751770AbbHCKxa (ORCPT ); Mon, 3 Aug 2015 06:53:30 -0400 Date: Mon, 3 Aug 2015 13:53:27 +0300 From: "Kirill A. Shutemov" To: Jerome Marchand Cc: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli , Hugh Dickins , Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv9 30/36] thp: add option to setup migration entiries during PMD split Message-ID: <20150803105327.GD25034@node.dhcp.inet.fi> References: <1437402069-105900-1-git-send-email-kirill.shutemov@linux.intel.com> <1437402069-105900-31-git-send-email-kirill.shutemov@linux.intel.com> <55BB8FB2.6040004@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55BB8FB2.6040004@redhat.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3997 Lines: 93 On Fri, Jul 31, 2015 at 05:09:38PM +0200, Jerome Marchand wrote: > On 07/20/2015 04:21 PM, Kirill A. Shutemov wrote: > > We are going to use migration PTE entires to stabilize page counts. > > If the page is mapped with PMDs we need to split the PMD and setup > > migration enties. It's reasonable to combine these operations to avoid > > double-scanning over the page table. > > Entries? Three different typos for three occurrences of the same word. > You don't like it, do you? Urgh.. >From 6c5b35ffcc425bcfc91b56d1ee404ab83cc667cf Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 10 Apr 2015 12:39:14 +0300 Subject: [PATCH] thp: add option to setup migration entries during PMD split We are going to use migration PTE entries to stabilize page counts. If the page is mapped with PMDs we need to split the PMD and setup migration entries. It's reasonable to combine these operations to avoid double-scanning over the page table. Signed-off-by: Kirill A. Shutemov Tested-by: Sasha Levin Tested-by: Aneesh Kumar K.V Acked-by: Vlastimil Babka Acked-by: Jerome Marchand --- mm/huge_memory.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1e0e02786241..0d817863a739 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -2627,7 +2628,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, } static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, - unsigned long haddr) + unsigned long haddr, bool freeze) { struct mm_struct *mm = vma->vm_mm; struct page *page; @@ -2669,12 +2670,18 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, * transferred to avoid any possibility of altering * permissions across VMAs. */ - entry = mk_pte(page + i, vma->vm_page_prot); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); - if (!write) - entry = pte_wrprotect(entry); - if (!young) - entry = pte_mkold(entry); + if (freeze) { + swp_entry_t swp_entry; + swp_entry = make_migration_entry(page + i, write); + entry = swp_entry_to_pte(swp_entry); + } else { + entry = mk_pte(page + i, vma->vm_page_prot); + entry = maybe_mkwrite(pte_mkdirty(entry), vma); + if (!write) + entry = pte_wrprotect(entry); + if (!young) + entry = pte_mkold(entry); + } pte = pte_offset_map(&_pmd, haddr); BUG_ON(!pte_none(*pte)); set_pte_at(mm, haddr, pte, entry); @@ -2715,7 +2722,7 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PMD_SIZE); ptl = pmd_lock(mm, pmd); if (likely(pmd_trans_huge(*pmd))) - __split_huge_pmd_locked(vma, pmd, haddr); + __split_huge_pmd_locked(vma, pmd, haddr, false); spin_unlock(ptl); mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PMD_SIZE); } -- Kirill A. Shutemov -- 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/