Re: [RFC][PATCH 0/9] extend hugepage migration

From: Simon Jeons <simon.jeons@gmail.com>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	Mel Gorman <mel@csn.ul.ie>, Hugh Dickins <hughd@google.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Andi Kleen <andi@firstfloor.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH 0/9] extend hugepage migration
Date: Wed, 20 Mar 2013 07:43:44 +0800	[thread overview]
Message-ID: <5148F830.3070601@gmail.com> (raw)
In-Reply-To: <1361475708-25991-1-git-send-email-n-horiguchi@ah.jp.nec.com>

Hi Naoya,
On 02/22/2013 03:41 AM, Naoya Horiguchi wrote:
> Hi,
>
> Hugepage migration is now available only for soft offlining (moving
> data on the half corrupted page to another page to save the data).
> But it's also useful some other users of page migration, so this
> patchset tries to extend some of such users to support hugepage.
>
> The targets of this patchset are NUMA related system calls (i.e.
> migrate_pages(2), move_pages(2), and mbind(2)), and memory hotplug.
> This patchset does not extend page migration in memory compaction,
> because I think that users of memory compaction mainly expect to
> construct thp by arranging raw pages but hugepage migration doesn't
> help it.
> CMA, another user of page migration, can have benefit from hugepage
> migration, but is not enabled to support it now. This is because
> I've never used CMA and need to learn more to extend and/or test
> hugepage migration in CMA. I'll add this in later version if it
> becomes ready, or will post as a separate patchset.
>
> Hugepage migration of 1GB hugepage is not enabled for now, because
> I'm not sure whether users of 1GB hugepage really want it.
> We need to spare free hugepage in order to do migration, but I don't
> think that users want to 1GB memory to idle for that purpose
> (currently we can't expand/shrink 1GB hugepage pool after boot).
>
> Could you review and give me some comments/feedbacks?
>
> Thanks,
> Naoya Horiguchi
> ---
> Easy patch access:
>    git@github.com:Naoya-Horiguchi/linux.git
>    branch:extend_hugepage_migration
>
> Test code:
>    git@github.com:Naoya-Horiguchi/test_hugepage_migration_extension.git

git clone 
git@github.com:Naoya-Horiguchi/test_hugepage_migration_extension.git
Cloning into test_hugepage_migration_extension...
Permission denied (publickey).
fatal: The remote end hung up unexpectedly

>
> Naoya Horiguchi (9):
>        migrate: add migrate_entry_wait_huge()
>        migrate: make core migration code aware of hugepage
>        soft-offline: use migrate_pages() instead of migrate_huge_page()
>        migrate: clean up migrate_huge_page()
>        migrate: enable migrate_pages() to migrate hugepage
>        migrate: enable move_pages() to migrate hugepage
>        mbind: enable mbind() to migrate hugepage
>        memory-hotplug: enable memory hotplug to handle hugepage
>        remove /proc/sys/vm/hugepages_treat_as_movable
>
>   Documentation/sysctl/vm.txt |  16 ------
>   include/linux/hugetlb.h     |  25 ++++++++--
>   include/linux/mempolicy.h   |   2 +-
>   include/linux/migrate.h     |  12 ++---
>   include/linux/swapops.h     |   4 ++
>   kernel/sysctl.c             |   7 ---
>   mm/hugetlb.c                |  98 ++++++++++++++++++++++++++++--------
>   mm/memory-failure.c         |  20 ++++++--
>   mm/memory.c                 |   6 ++-
>   mm/memory_hotplug.c         |  51 +++++++++++++++----
>   mm/mempolicy.c              |  61 +++++++++++++++--------
>   mm/migrate.c                | 119 ++++++++++++++++++++++++++++++--------------
>   mm/page_alloc.c             |  12 +++++
>   mm/page_isolation.c         |   5 ++
>   14 files changed, 311 insertions(+), 127 deletions(-)
>
> --
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