From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CE1FC64EB1 for ; Fri, 7 Dec 2018 05:42:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5859320892 for ; Fri, 7 Dec 2018 05:42:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5859320892 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726227AbeLGFmI (ORCPT ); Fri, 7 Dec 2018 00:42:08 -0500 Received: from mga01.intel.com ([192.55.52.88]:55177 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726212AbeLGFmE (ORCPT ); Fri, 7 Dec 2018 00:42:04 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Dec 2018 21:42:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,324,1539673200"; d="scan'208";a="105567298" Received: from yhuang-mobile.sh.intel.com ([10.239.196.133]) by fmsmga007.fm.intel.com with ESMTP; 06 Dec 2018 21:42:01 -0800 From: Huang Ying 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 Subject: [PATCH -V8 13/21] swap: Support PMD swap mapping in madvise_free() Date: Fri, 7 Dec 2018 13:41:13 +0800 Message-Id: <20181207054122.27822-14-ying.huang@intel.com> X-Mailer: git-send-email 2.18.1 In-Reply-To: <20181207054122.27822-1-ying.huang@intel.com> References: <20181207054122.27822-1-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When madvise_free() found a PMD swap mapping, if only part of the huge swap cluster is operated on, the PMD swap mapping will be split and fallback to PTE swap mapping processing. Otherwise, if all huge swap cluster is operated on, free_swap_and_cache() will be called to decrease the PMD swap mapping count and probably free the swap space and the THP in swap cache too. 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/huge_memory.c | 52 ++++++++++++++++++++++++++++++++++-------------- mm/madvise.c | 2 +- 2 files changed, 38 insertions(+), 16 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f3c0a9e8fb9a..9cf5d4fa6d98 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1899,6 +1899,15 @@ int do_huge_pmd_swap_page(struct vm_fault *vmf, pmd_t orig_pmd) } #endif +static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) +{ + pgtable_t pgtable; + + pgtable = pgtable_trans_huge_withdraw(mm, pmd); + pte_free(mm, pgtable); + mm_dec_nr_ptes(mm); +} + /* * Return true if we do MADV_FREE successfully on entire pmd page. * Otherwise, return false. @@ -1919,15 +1928,37 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, goto out_unlocked; orig_pmd = *pmd; - if (is_huge_zero_pmd(orig_pmd)) - goto out; - if (unlikely(!pmd_present(orig_pmd))) { - VM_BUG_ON(thp_migration_supported() && - !is_pmd_migration_entry(orig_pmd)); - goto out; + swp_entry_t entry = pmd_to_swp_entry(orig_pmd); + + if (is_migration_entry(entry)) { + VM_BUG_ON(!thp_migration_supported()); + goto out; + } else if (IS_ENABLED(CONFIG_THP_SWAP) && + !non_swap_entry(entry)) { + /* + * If part of THP is discarded, split the PMD + * swap mapping and operate on the PTEs + */ + if (next - addr != HPAGE_PMD_SIZE) { + __split_huge_swap_pmd(vma, addr, pmd); + goto out; + } + free_swap_and_cache(entry, HPAGE_PMD_NR); + pmd_clear(pmd); + zap_deposited_table(mm, pmd); + if (current->mm == mm) + sync_mm_rss(mm); + add_mm_counter(mm, MM_SWAPENTS, -HPAGE_PMD_NR); + ret = true; + goto out; + } else + VM_BUG_ON(1); } + if (is_huge_zero_pmd(orig_pmd)) + goto out; + page = pmd_page(orig_pmd); /* * If other processes are mapping this page, we couldn't discard @@ -1973,15 +2004,6 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, return ret; } -static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) -{ - pgtable_t pgtable; - - pgtable = pgtable_trans_huge_withdraw(mm, pmd); - pte_free(mm, pgtable); - mm_dec_nr_ptes(mm); -} - int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr) { diff --git a/mm/madvise.c b/mm/madvise.c index cbb3d7e38e51..0c1f96c605f8 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -321,7 +321,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, unsigned long next; next = pmd_addr_end(addr, end); - if (pmd_trans_huge(*pmd)) + if (pmd_trans_huge(*pmd) || is_swap_pmd(*pmd)) if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) goto next; -- 2.18.1