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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 59515ECDE47 for ; Thu, 8 Nov 2018 08:23:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29ABC20827 for ; Thu, 8 Nov 2018 08:23:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29ABC20827 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org 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 S1726744AbeKHR6B (ORCPT ); Thu, 8 Nov 2018 12:58:01 -0500 Received: from alexa-out-blr-02.qualcomm.com ([103.229.18.198]:32566 "EHLO alexa-out-blr.qualcomm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726162AbeKHR6A (ORCPT ); Thu, 8 Nov 2018 12:58:00 -0500 X-IronPort-AV: E=Sophos;i="5.54,478,1534789800"; d="scan'208";a="233229" Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by alexa-out-blr.qualcomm.com with ESMTP/TLS/AES256-SHA; 08 Nov 2018 13:53:23 +0530 X-IronPort-AV: E=McAfee;i="5900,7806,9070"; a="5699120" Received: from blr-ubuntu-104.ap.qualcomm.com (HELO blr-ubuntu-104.qualcomm.com) ([10.79.40.64]) by ironmsg01-blr.qualcomm.com with ESMTP; 08 Nov 2018 13:53:22 +0530 Received: by blr-ubuntu-104.qualcomm.com (Postfix, from userid 346745) id 137E923A8; Thu, 8 Nov 2018 13:53:21 +0530 (IST) From: Arun KS To: akpm@linux-foundation.org, keescook@chromium.org, khlebnikov@yandex-team.ru, minchan@kernel.org, mhocko@kernel.org, vbabka@suse.cz, osalvador@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: getarunks@gmail.com, Arun KS Subject: [PATCH v3 0/4] mm: convert totalram_pages, totalhigh_pages and managed pages to atomic Date: Thu, 8 Nov 2018 13:53:14 +0530 Message-Id: <1541665398-29925-1-git-send-email-arunks@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series convert totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. The patch was comiple tested on x86(x86_64_defconfig & i386_defconfig) on 4.20-rc1. And memory hotplug tested on arm64, but on an older version of kernel. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. Changes in v3: - Fixed kbuild test robot errors. - Modifed changelogs to be more clear. - EXPORT_SYMBOL for _totalram_pages and _totalhigh_pages. Arun KS (4): mm: reference totalram_pages and managed_pages once per function mm: convert zone->managed_pages to atomic variable mm: convert totalram_pages and totalhigh_pages variables to atomic mm: Remove managed_page_count spinlock arch/csky/mm/init.c | 4 +- arch/powerpc/platforms/pseries/cmm.c | 10 ++-- arch/s390/mm/init.c | 2 +- arch/um/kernel/mem.c | 3 +- arch/x86/kernel/cpu/microcode/core.c | 5 +- drivers/char/agp/backend.c | 4 +- drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 2 +- drivers/gpu/drm/i915/i915_gem.c | 2 +- drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 4 +- drivers/hv/hv_balloon.c | 19 +++---- drivers/md/dm-bufio.c | 2 +- drivers/md/dm-crypt.c | 2 +- drivers/md/dm-integrity.c | 2 +- drivers/md/dm-stats.c | 2 +- drivers/media/platform/mtk-vpu/mtk_vpu.c | 2 +- drivers/misc/vmw_balloon.c | 2 +- drivers/parisc/ccio-dma.c | 4 +- drivers/parisc/sba_iommu.c | 4 +- drivers/staging/android/ion/ion_system_heap.c | 2 +- drivers/xen/xen-selfballoon.c | 6 +-- fs/ceph/super.h | 2 +- fs/file_table.c | 7 +-- fs/fuse/inode.c | 2 +- fs/nfs/write.c | 2 +- fs/nfsd/nfscache.c | 2 +- fs/ntfs/malloc.h | 2 +- fs/proc/base.c | 2 +- include/linux/highmem.h | 28 ++++++++++- include/linux/mm.h | 27 +++++++++- include/linux/mmzone.h | 15 +++--- include/linux/swap.h | 1 - kernel/fork.c | 5 +- kernel/kexec_core.c | 5 +- kernel/power/snapshot.c | 2 +- lib/show_mem.c | 2 +- mm/highmem.c | 5 +- mm/huge_memory.c | 2 +- mm/kasan/quarantine.c | 2 +- mm/memblock.c | 6 +-- mm/mm_init.c | 2 +- mm/oom_kill.c | 2 +- mm/page_alloc.c | 72 +++++++++++++-------------- mm/shmem.c | 7 +-- mm/slab.c | 2 +- mm/swap.c | 2 +- mm/util.c | 2 +- mm/vmalloc.c | 4 +- mm/vmstat.c | 4 +- mm/workingset.c | 2 +- mm/zswap.c | 4 +- net/dccp/proto.c | 7 +-- net/decnet/dn_route.c | 2 +- net/ipv4/tcp_metrics.c | 2 +- net/netfilter/nf_conntrack_core.c | 7 +-- net/netfilter/xt_hashlimit.c | 5 +- net/sctp/protocol.c | 7 +-- security/integrity/ima/ima_kexec.c | 2 +- 57 files changed, 195 insertions(+), 142 deletions(-) -- 1.9.1