From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-f72.google.com (mail-ot1-f72.google.com [209.85.210.72]) by kanga.kvack.org (Postfix) with ESMTP id 45F966B02B7 for ; Wed, 31 Oct 2018 09:00:14 -0400 (EDT) Received: by mail-ot1-f72.google.com with SMTP id x9so6105187otg.19 for ; Wed, 31 Oct 2018 06:00:14 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id n32si3582442otb.32.2018.10.31.06.00.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 31 Oct 2018 06:00:13 -0700 (PDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w9VCx5mq110152 for ; Wed, 31 Oct 2018 09:00:12 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2nfbgy46a3-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 31 Oct 2018 09:00:12 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 31 Oct 2018 13:00:09 -0000 From: Martin Schwidefsky Subject: [PATCH 3/4] mm: add mm_pxd_folded checks to pgtable_bytes accounting functions Date: Wed, 31 Oct 2018 14:00:00 +0100 In-Reply-To: <1540990801-4261-1-git-send-email-schwidefsky@de.ibm.com> References: <1540990801-4261-1-git-send-email-schwidefsky@de.ibm.com> Message-Id: <1540990801-4261-4-git-send-email-schwidefsky@de.ibm.com> Content-Type: text/plain Content-Transfer-Encoding: 8bit MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Li Wang , Guenter Roeck , Janosch Frank , "Kirill A. Shutemov" , Heiko Carstens , linux-kernel , Linux-MM Cc: Martin Schwidefsky The common mm code calls mm_dec_nr_pmds() and mm_dec_nr_puds() in free_pgtables() if the address range spans a full pud or pmd. If mm_dec_nr_puds/mm_dec_nr_pmds are non-empty due to configuration settings they blindly subtract the size of the pmd or pud table from pgtable_bytes even if the pud or pmd page table layer is folded. Add explicit mm_[pmd|pud]_folded checks to the four pgtable_bytes accounting functions mm_inc_nr_puds, mm_inc_nr_pmds, mm_dec_nr_puds and mm_dec_nr_pmds. As the check for folded page tables can be overwritten by the architecture, this allows to keep a correct pgtable_bytes value for platforms that use a dynamic number of page table levels. Acked-by: Kirill A. Shutemov Signed-off-by: Martin Schwidefsky --- include/linux/mm.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 1e52b8f..844a853 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1744,11 +1744,15 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address); static inline void mm_inc_nr_puds(struct mm_struct *mm) { + if (mm_pud_folded(mm)) + return; atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes); } static inline void mm_dec_nr_puds(struct mm_struct *mm) { + if (mm_pud_folded(mm)) + return; atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes); } #endif @@ -1768,11 +1772,15 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address); static inline void mm_inc_nr_pmds(struct mm_struct *mm) { + if (mm_pmd_folded(mm)) + return; atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes); } static inline void mm_dec_nr_pmds(struct mm_struct *mm) { + if (mm_pmd_folded(mm)) + return; atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes); } #endif -- 2.7.4