From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 8D63D6B002B for ; Mon, 16 Apr 2018 22:03:33 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id p12so10439622pfn.13 for ; Mon, 16 Apr 2018 19:03:33 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id q74si633723pfi.282.2018.04.16.19.03.31 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Apr 2018 19:03:32 -0700 (PDT) From: "Huang, Ying" Subject: [PATCH -mm 18/21] mm, THP, swap: Support PMD swap mapping in mincore() Date: Tue, 17 Apr 2018 10:02:27 +0800 Message-Id: <20180417020230.26412-19-ying.huang@intel.com> In-Reply-To: <20180417020230.26412-1-ying.huang@intel.com> References: <20180417020230.26412-1-ying.huang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Tim Chen , Andi Kleen , 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 From: Huang Ying During mincore(), for PMD swap mapping, swap cache will be looked up. If the resulting page isn't compound page, the PMD swap mapping will be split and fallback to PTE swap mapping processing. 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 --- mm/mincore.c | 37 +++++++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 6 deletions(-) diff --git a/mm/mincore.c b/mm/mincore.c index a66f2052c7b1..897dd2c187e8 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -48,7 +48,8 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr, * and is up to date; i.e. that no page-in operation would be required * at this time if an application were to map and access this page. */ -static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff) +static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff, + bool *compound) { unsigned char present = 0; struct page *page; @@ -86,6 +87,8 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff) #endif if (page) { present = PageUptodate(page); + if (compound) + *compound = PageCompound(page); put_page(page); } @@ -103,7 +106,8 @@ static int __mincore_unmapped_range(unsigned long addr, unsigned long end, pgoff = linear_page_index(vma, addr); for (i = 0; i < nr; i++, pgoff++) - vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); + vec[i] = mincore_page(vma->vm_file->f_mapping, + pgoff, NULL); } else { for (i = 0; i < nr; i++) vec[i] = 0; @@ -127,14 +131,36 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, pte_t *ptep; unsigned char *vec = walk->private; int nr = (end - addr) >> PAGE_SHIFT; + swp_entry_t entry; ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { - memset(vec, 1, nr); + unsigned char val = 1; + bool compound; + + if (thp_swap_supported() && is_swap_pmd(*pmd)) { + entry = pmd_to_swp_entry(*pmd); + if (!non_swap_entry(entry)) { + val = mincore_page(swap_address_space(entry), + swp_offset(entry), + &compound); + /* + * The huge swap cluster has been + * split under us + */ + if (!compound) { + __split_huge_swap_pmd(vma, addr, pmd); + spin_unlock(ptl); + goto fallback; + } + } + } + memset(vec, val, nr); spin_unlock(ptl); goto out; } +fallback: if (pmd_trans_unstable(pmd)) { __mincore_unmapped_range(addr, end, vma, vec); goto out; @@ -150,8 +176,7 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, else if (pte_present(pte)) *vec = 1; else { /* pte is a swap entry */ - swp_entry_t entry = pte_to_swp_entry(pte); - + entry = pte_to_swp_entry(pte); if (non_swap_entry(entry)) { /* * migration or hwpoison entries are always @@ -161,7 +186,7 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, } else { #ifdef CONFIG_SWAP *vec = mincore_page(swap_address_space(entry), - swp_offset(entry)); + swp_offset(entry), NULL); #else WARN_ON(1); *vec = 1; -- 2.17.0