Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   =?iso-2022-jp?B?SE9SSUdVQ0hJIE5BT1lBKBskQktZOH0hIUQ+TGkbKEIp?= 
        <naoya.horiguchi@nec.com>
To:     Andrew Morton <akpm@linux-foundation.org>
CC:     "nao.horiguchi@gmail.com" <nao.horiguchi@gmail.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "mhocko@kernel.org" <mhocko@kernel.org>,
        "mike.kravetz@oracle.com" <mike.kravetz@oracle.com>,
        "osalvador@suse.de" <osalvador@suse.de>,
        "tony.luck@intel.com" <tony.luck@intel.com>,
        "david@redhat.com" <david@redhat.com>,
        "aneesh.kumar@linux.vnet.ibm.com" <aneesh.kumar@linux.vnet.ibm.com>,
        "zeil@yandex-team.ru" <zeil@yandex-team.ru>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 00/15] HWPOISON: soft offline rework
Thread-Topic: [PATCH v3 00/15] HWPOISON: soft offline rework
Thread-Index: AQHWSlwottUppHD7sEaxjlCDSVewGKjoWwgA
Date:   Wed, 24 Jun 2020 22:36:18 +0000
Message-ID: <20200624223618.GA13133@hori.linux.bs1.fc.nec.co.jp>
References: <20200624150137.7052-1-nao.horiguchi@gmail.com>
 <20200624121742.711331a2a65633a0e16fd9e6@linux-foundation.org>
In-Reply-To: <20200624121742.711331a2a65633a0e16fd9e6@linux-foundation.org>
Accept-Language: ja-JP, en-US
Content-Language: en-US
Content-Type: text/plain; charset="iso-2022-jp"
Content-ID: <1B98CB1C80B07449AD2D8C0681ECF62A@jpnprd01.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: a5bfc718-85a2-4ce0-9d96-08d8188f0347
X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Jun 2020 22:36:18.6550
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: e67df547-9d0d-4f4d-9161-51c6ed1f7d11
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: PkXIIYP95GgCppS3sxkoE65IDE6Rdf8LcdyxrmsH/1J/v8TGuYAvdV7uToX+2wdLa6mJjZZngcNXTX8H7xhC3w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: TY2PR01MB4076
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Jun 24, 2020 at 12:17:42PM -0700, Andrew Morton wrote:
> On Wed, 24 Jun 2020 15:01:22 +0000 nao.horiguchi@gmail.com wrote:
>=20
> > I rebased soft-offline rework patchset [1][2] onto the latest mmotm.  T=
he
> > rebasing required some non-trivial changes to adjust, but mainly that w=
as
> > straightforward.  I confirmed that the reported problem doesn't reprodu=
ce on
> > compaction after soft offline.  For more precise description of the pro=
blem
> > and the motivation of this patchset, please see [2].
> >=20
> > I think that the following two patches in v2 are better to be done with
> > separate work of hard-offline rework, so it's not included in this seri=
es.
> >=20
> >   - mm,hwpoison: Take pages off the buddy when hard-offlining
> >   - mm/hwpoison-inject: Rip off duplicated checks
> >=20
> > These two are not directly related to the reported problem, so they see=
ms
> > not urgent.  And the first one breaks num_poisoned_pages counting in so=
me
> > testcases, and The second patch needs more consideration about commente=
d point.
> >=20
>=20
> It would be nice to have some sort of overview of the patch series in
> this [0/n] email.
>=20
> > [1] v1: https://lore.kernel.org/linux-mm/1541746035-13408-1-git-send-em=
ail-n-horiguchi@ah.jp.nec.com/
> > [2] v2: https://lore.kernel.org/linux-mm/20191017142123.24245-1-osalvad=
or@suse.de/
>=20
> The above have such, but are they up to date?

The description of the problem doesn't change, but there're some new patche=
s
and some patches are postponed, so I should've added an overview of this se=
ries:

- patch 1, 2 are cleanups.
- patch 3, 4, 5 change the precondition when calling memory_failure(). Prev=
iously
  we sometimes call it with holding refcount of the target page and somtime=
s call
  without holding it, and we passed a flag of whether refcount was taken ou=
t of
  memory_failure().  It was confusing and caused code more complex than nee=
ded.
- patch 6-10 are cleanups.
- patch 11 introduces new logic to remove the error page from buddy allocat=
or,
  which is also applied to the path of soft-offling in-use pages in patch 1=
2.
- patch 13 is basically a refactoring but I added some adjustment to make s=
ure
  that the freed page is surely sent back to buddy instead of being kept in=
 pcplist,
  which is based on discussion in v2.
- patch 14 fixes the inconsistency of return values between injection inter=
faces.
- patch 15 is a new patch to complement missing code found in code review f=
or
  previous version.

Core change is in patch 11 and 12, and the others are kind of cleanup/refac=
toring.

Thanks,
Naoya Horiguchi=