From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by kanga.kvack.org (Postfix) with ESMTP id 70DDA6B7EB3 for ; Fri, 7 Dec 2018 00:42:20 -0500 (EST) Received: by mail-pg1-f197.google.com with SMTP id m16so1851325pgd.0 for ; Thu, 06 Dec 2018 21:42:20 -0800 (PST) Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id cf16si2126256plb.227.2018.12.06.21.42.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Dec 2018 21:42:18 -0800 (PST) From: Huang Ying Subject: [PATCH -V8 18/21] swap: Support PMD swap mapping in mincore() Date: Fri, 7 Dec 2018 13:41:18 +0800 Message-Id: <20181207054122.27822-19-ying.huang@intel.com> In-Reply-To: <20181207054122.27822-1-ying.huang@intel.com> References: <20181207054122.27822-1-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 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 Cc: Daniel Jordan --- mm/mincore.c | 37 +++++++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 6 deletions(-) diff --git a/mm/mincore.c b/mm/mincore.c index aa0e542569f9..1d861fac82ee 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 (IS_ENABLED(CONFIG_THP_SWAP) && 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; -- 2.18.1