Re: [PATCH v1 0/4]mm: convert totalram_pages, totalhigh_pages and managed pages to atomic

From: Arun KS <arunks@codeaurora.org>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
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
Date: Tue, 06 Nov 2018 14:00:14 +0530	[thread overview]
Message-ID: <08a61c003eed0280fd82f6200debcbca@codeaurora.org> (raw)
In-Reply-To: <63d9f48c-e39f-d345-0fb6-2f04afe769a2@yandex-team.ru>

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.

Will update the comment.

Regards,
Arun

> 
> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> 
>> 
>> 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):
>>> A  mm: Fix multiple evaluvations of totalram_pages and managed_pages
>>> A  mm: Convert zone->managed_pages to atomic variable
>>> A  mm: convert totalram_pages and totalhigh_pages variables to atomic
>>> A  mm: Remove managed_page_count spinlock
>>> 
>>> A arch/csky/mm/init.cA A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A arch/powerpc/platforms/pseries/cmm.cA A A A A A A A A  | 10 ++--
>>> A arch/s390/mm/init.cA A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A arch/um/kernel/mem.cA A A A A A A A A A A A A A A A A A A A A A A A A  |A  3 +-
>>> A arch/x86/kernel/cpu/microcode/core.cA A A A A A A A A  |A  5 +-
>>> A drivers/char/agp/backend.cA A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A drivers/gpu/drm/amd/amdkfd/kfd_crat.cA A A A A A A A  |A  2 +-
>>> A drivers/gpu/drm/i915/i915_gem.cA A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/gpu/drm/i915/selftests/i915_gem_gtt.c |A  4 +-
>>> A drivers/hv/hv_balloon.cA A A A A A A A A A A A A A A A A A A A A A  | 19 +++----
>>> A drivers/md/dm-bufio.cA A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/md/dm-crypt.cA A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/md/dm-integrity.cA A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/md/dm-stats.cA A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/media/platform/mtk-vpu/mtk_vpu.cA A A A A  |A  2 +-
>>> A drivers/misc/vmw_balloon.cA A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A drivers/parisc/ccio-dma.cA A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A drivers/parisc/sba_iommu.cA A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A drivers/staging/android/ion/ion_system_heap.c |A  2 +-
>>> A drivers/xen/xen-selfballoon.cA A A A A A A A A A A A A A A A  |A  6 +--
>>> A fs/ceph/super.hA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A fs/file_table.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  7 +--
>>> A fs/fuse/inode.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A fs/nfs/write.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A fs/nfsd/nfscache.cA A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A fs/ntfs/malloc.hA A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A fs/proc/base.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A include/linux/highmem.hA A A A A A A A A A A A A A A A A A A A A A  | 28 ++++++++++-
>>> A include/linux/mm.hA A A A A A A A A A A A A A A A A A A A A A A A A A A  | 27 +++++++++-
>>> A include/linux/mmzone.hA A A A A A A A A A A A A A A A A A A A A A A  | 15 +++---
>>> A include/linux/swap.hA A A A A A A A A A A A A A A A A A A A A A A A A  |A  1 -
>>> A kernel/fork.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  5 +-
>>> A kernel/kexec_core.cA A A A A A A A A A A A A A A A A A A A A A A A A A  |A  5 +-
>>> A kernel/power/snapshot.cA A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A lib/show_mem.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/highmem.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A mm/huge_memory.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/kasan/quarantine.cA A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/memblock.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  6 +--
>>> A mm/memory_hotplug.cA A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A mm/mm_init.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/oom_kill.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/page_alloc.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  | 71 
>>> +++++++++++++--------------
>>> A mm/shmem.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  7 +--
>>> A mm/slab.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/swap.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/util.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/vmalloc.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A mm/vmstat.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A mm/workingset.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A mm/zswap.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  4 +-
>>> A net/dccp/proto.cA A A A A A A A A A A A A A A A A A A A A A A A A A A A A  |A  7 +--
>>> A net/decnet/dn_route.cA A A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A net/ipv4/tcp_metrics.cA A A A A A A A A A A A A A A A A A A A A A A  |A  2 +-
>>> A net/netfilter/nf_conntrack_core.cA A A A A A A A A A A A  |A  7 +--
>>> A net/netfilter/xt_hashlimit.cA A A A A A A A A A A A A A A A A  |A  5 +-
>>> A net/sctp/protocol.cA A A A A A A A A A A A A A A A A A A A A A A A A A  |A  7 +--
>>> A security/integrity/ima/ima_kexec.cA A A A A A A A A A A  |A  2 +-
>>> A 58 files changed, 195 insertions(+), 144 deletions(-)