From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) by kanga.kvack.org (Postfix) with ESMTP id 9DEF26B0278 for ; Wed, 10 Oct 2018 03:27:43 -0400 (EDT) Received: by mail-pl1-f200.google.com with SMTP id t9-v6so3174400plq.15 for ; Wed, 10 Oct 2018 00:27:43 -0700 (PDT) Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id n84-v6si21364295pfg.127.2018.10.10.00.27.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Oct 2018 00:27:42 -0700 (PDT) From: Huang Ying Subject: [PATCH -V6 17/21] swap: Support PMD swap mapping for MADV_WILLNEED Date: Wed, 10 Oct 2018 15:19:20 +0800 Message-Id: <20181010071924.18767-18-ying.huang@intel.com> In-Reply-To: <20181010071924.18767-1-ying.huang@intel.com> References: <20181010071924.18767-1-ying.huang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , "Kirill A. Shutemov" , Andrea Arcangeli , Michal Hocko , Johannes Weiner , Shaohua Li , Hugh Dickins , Minchan Kim , Rik van Riel , Dave Hansen , Naoya Horiguchi , Zi Yan , Daniel Jordan During MADV_WILLNEED, for a PMD swap mapping, if THP swapin is enabled for the VMA, the whole swap cluster will be swapin. Otherwise, the huge swap cluster and the PMD swap mapping will be split and fallback to PTE swap mapping. Signed-off-by: "Huang, Ying" Cc: "Kirill A. Shutemov" Cc: Andrea Arcangeli Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dave Hansen Cc: Naoya Horiguchi Cc: Zi Yan Cc: Daniel Jordan --- mm/madvise.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 20101ff125d0..0413659ff6ba 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -196,14 +196,36 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, pte_t *orig_pte; struct vm_area_struct *vma = walk->private; unsigned long index; + swp_entry_t entry; + struct page *page; + pmd_t pmdval; + + pmdval = *pmd; + if (IS_ENABLED(CONFIG_THP_SWAP) && is_swap_pmd(pmdval) && + !is_pmd_migration_entry(pmdval)) { + entry = pmd_to_swp_entry(pmdval); + if (!transparent_hugepage_swapin_enabled(vma)) { + if (!split_swap_cluster(entry, 0)) + split_huge_swap_pmd(vma, pmd, start, pmdval); + } else { + page = read_swap_cache_async(entry, + GFP_HIGHUSER_MOVABLE, + vma, start, false); + if (page) { + /* The swap cluster has been split under us */ + if (!PageTransHuge(page)) + split_huge_swap_pmd(vma, pmd, start, + pmdval); + put_page(page); + } + } + } if (pmd_none_or_trans_huge_or_clear_bad(pmd)) return 0; for (index = start; index != end; index += PAGE_SIZE) { pte_t pte; - swp_entry_t entry; - struct page *page; spinlock_t *ptl; orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); -- 2.16.4