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 978056B0272 for ; Wed, 23 May 2018 04:27:18 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id p189-v6so12807161pfp.2 for ; Wed, 23 May 2018 01:27:18 -0700 (PDT) Received: from mga17.intel.com (mga17.intel.com. [192.55.52.151]) by mx.google.com with ESMTPS id d2-v6si18038840plh.387.2018.05.23.01.27.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 May 2018 01:27:17 -0700 (PDT) From: "Huang, Ying" Subject: [PATCH -mm -V3 16/21] mm, THP, swap: Free PMD swap mapping when zap_huge_pmd() Date: Wed, 23 May 2018 16:26:20 +0800 Message-Id: <20180523082625.6897-17-ying.huang@intel.com> In-Reply-To: <20180523082625.6897-1-ying.huang@intel.com> References: <20180523082625.6897-1-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 From: Huang Ying For a PMD swap mapping, zap_huge_pmd() will clear the PMD and call free_swap_and_cache() to decrease the swap reference count and maybe free or split the huge swap cluster and the THP in swap cache. 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/huge_memory.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 01fdd59fe6d4..e057b966ea68 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2007,7 +2007,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, spin_unlock(ptl); if (is_huge_zero_pmd(orig_pmd)) tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE); - } else if (is_huge_zero_pmd(orig_pmd)) { + } else if (pmd_present(orig_pmd) && is_huge_zero_pmd(orig_pmd)) { zap_deposited_table(tlb->mm, pmd); spin_unlock(ptl); tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE); @@ -2020,17 +2020,27 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, page_remove_rmap(page, true); VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); VM_BUG_ON_PAGE(!PageHead(page), page); - } else if (thp_migration_supported()) { - swp_entry_t entry; - - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); - entry = pmd_to_swp_entry(orig_pmd); - page = pfn_to_page(swp_offset(entry)); + } else { + swp_entry_t entry = pmd_to_swp_entry(orig_pmd); + + if (thp_migration_supported() && + is_migration_entry(entry)) + page = pfn_to_page(swp_offset(entry)); + else if (thp_swap_supported() && + !non_swap_entry(entry)) + free_swap_and_cache(entry, true); + else { + WARN_ONCE(1, +"Non present huge pmd without pmd migration or swap enabled!"); + goto unlock; + } flush_needed = 0; - } else - WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!"); + } - if (PageAnon(page)) { + if (!page) { + zap_deposited_table(tlb->mm, pmd); + add_mm_counter(tlb->mm, MM_SWAPENTS, -HPAGE_PMD_NR); + } else if (PageAnon(page)) { zap_deposited_table(tlb->mm, pmd); add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); } else { @@ -2038,7 +2048,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, zap_deposited_table(tlb->mm, pmd); add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR); } - +unlock: spin_unlock(ptl); if (flush_needed) tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE); -- 2.16.1