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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 E3FEFC32789 for ; Tue, 6 Nov 2018 08:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C52A20862 for ; Tue, 6 Nov 2018 08:43:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ASoO0XpQ"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="EykZ5w3b" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C52A20862 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 S2387867AbeKFSHX (ORCPT ); Tue, 6 Nov 2018 13:07:23 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:37830 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729416AbeKFSHX (ORCPT ); Tue, 6 Nov 2018 13:07:23 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 869C161327; Tue, 6 Nov 2018 08:43:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1541493794; bh=ydZmGCYJJph9PcEyjP8vu4Bo8X1b57eb3CWoLdP/FZA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ASoO0XpQn5i4P+yLfVWXnEJnnZO3+cyyADlKy9Y1gBTYUSzh1pbg9JNuKry801xgf c7KJINfIdNVZSEl377qwovy+IW5lRnN63ozgonChZq0SbQIWodC42THoM2jiLg9je9 7c7bmamU3rEITLSJY2D8vqCU42ouTNnYchG0SiZA= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 82F7461482; Tue, 6 Nov 2018 08:43:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1541493792; bh=ydZmGCYJJph9PcEyjP8vu4Bo8X1b57eb3CWoLdP/FZA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=EykZ5w3b4CO4sFBxbDOH9zzW13CJRkM9pRgtAZPTOsazXjMUQB3WqfAerIcoDX+6b 85GyWp3IDIRJLgMh0vBeUPpoJFSL5ZDrbvnnol1d0xMXFvNH3nO5pnCfd4MhzFdgpb pOzpSegmfrW6egkafg2F1WBRi2uoRCshvnkdur9o= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Tue, 06 Nov 2018 14:13:12 +0530 From: Arun KS To: Konstantin Khlebnikov Cc: keescook@chromium.org, minchan@kernel.org, getarunks@gmail.com, gregkh@linuxfoundation.org, akpm@linux-foundation.org, mhocko@kernel.org, vbabka@suse.cz, linux-kernel@vger.kernel.org, linux-mm@kvack.org, julia.lawall@lip6.fr Subject: Re: [PATCH v1 0/4]mm: convert totalram_pages, totalhigh_pages and managed pages to atomic In-Reply-To: <10c88df6-dbb1-7490-628c-055d59b5ad8e@yandex-team.ru> References: <1540551662-26458-1-git-send-email-arunks@codeaurora.org> <9b210d4cc9925caf291412d7d45f16d7@codeaurora.org> <63d9f48c-e39f-d345-0fb6-2f04afe769a2@yandex-team.ru> <08a61c003eed0280fd82f6200debcbca@codeaurora.org> <10c88df6-dbb1-7490-628c-055d59b5ad8e@yandex-team.ru> Message-ID: <22fa2222012341a54f6b0b6aea341aa2@codeaurora.org> X-Sender: arunks@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-11-06 14:07, Konstantin Khlebnikov wrote: > On 06.11.2018 11:30, Arun KS wrote: >> On 2018-11-06 13:47, Konstantin Khlebnikov wrote: >>> On 06.11.2018 8:38, Arun KS wrote: >>>> Any comments? >>> >>> Looks good. >>> Except unclear motivation behind this change. >>> This should be in comment of one of patch. >> >> totalram_pages, zone->managed_pages and totalhigh_pages are sometimes >> modified outside managed_page_count_lock. Hence convert these variable >> to atomic to avoid readers potentially seeing a store tear. > > So, this is just theoretical issue or splat from sanitizer. > After boot memory online\offline are strictly serialized by > rw-semaphore. Few instances which can race with hot add. Please see below, https://patchwork.kernel.org/patch/10627521/ Regards, Arun > >> >> Will update the comment. >> >> Regards, >> Arun >> >>> >>> Reviewed-by: Konstantin Khlebnikov >>> >>>> >>>> Regards, >>>> Arun >>>> >>>> On 2018-10-26 16:30, Arun KS wrote: >>>>> 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 tip of linux-mmotm. And memory hotplug tested on arm64, but on >>>>> an >>>>> older version of kernel. >>>>> >>>>> Arun KS (4): >>>>>   mm: Fix multiple evaluvations of totalram_pages and managed_pages >>>>>   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                                  |  4 +- >>>>>  mm/huge_memory.c                              |  2 +- >>>>>  mm/kasan/quarantine.c                         |  2 +- >>>>>  mm/memblock.c                                 |  6 +-- >>>>>  mm/memory_hotplug.c                           |  4 +- >>>>>  mm/mm_init.c                                  |  2 +- >>>>>  mm/oom_kill.c                                 |  2 +- >>>>>  mm/page_alloc.c                               | 71 >>>>> +++++++++++++-------------- >>>>>  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 +- >>>>>  58 files changed, 195 insertions(+), 144 deletions(-)