Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Roman Gushchin <guro@fb.com>
To:     Andrew Morton <akpm@linux-foundation.org>
CC:     "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Kernel Team <Kernel-team@fb.com>,
        "Johannes Weiner" <hannes@cmpxchg.org>,
        Shakeel Butt <shakeelb@google.com>,
        "Vladimir Davydov" <vdavydov.dev@gmail.com>,
        Waiman Long <longman@redhat.com>
Subject: Re: [PATCH v6 00/10] mm: reparent slab memory on cgroup removal
Thread-Topic: [PATCH v6 00/10] mm: reparent slab memory on cgroup removal
Thread-Index: AQHVG0i11hwXEGSev06rqUx7yW/VhKaMc7gAgAEVDoA=
Date:   Wed, 5 Jun 2019 20:45:59 +0000
Message-ID: <20190605204555.GC10098@tower.DHCP.thefacebook.com>
References: <20190605024454.1393507-1-guro@fb.com>
 <20190604211418.70d178253550d96da46cee21@linux-foundation.org>
In-Reply-To: <20190604211418.70d178253550d96da46cee21@linux-foundation.org>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-messagesentrepresentingtype: 1
x-originating-ip: [2620:10d:c090:200::2:a19a]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: 9bab4133-a572-4471-8337-08d6e9f6d0b2
x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:BYAPR15MB2600;
x-ms-traffictypediagnostic: BYAPR15MB2600:
x-microsoft-antispam-prvs: <BYAPR15MB26008CB813EE481CBB8E608ABE160@BYAPR15MB2600.namprd15.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:7691;
x-forefront-prvs: 00594E8DBA
x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(136003)(396003)(39860400002)(366004)(376002)(346002)(189003)(199004)(76176011)(99286004)(68736007)(54906003)(316002)(52116002)(53936002)(6246003)(6916009)(6512007)(9686003)(25786009)(446003)(46003)(11346002)(4326008)(6116002)(476003)(486006)(478600001)(229853002)(14454004)(33656002)(73956011)(6436002)(66476007)(66556008)(64756008)(66946007)(66446008)(6486002)(305945005)(256004)(14444005)(1076003)(8936002)(81156014)(71200400001)(8676002)(71190400001)(7736002)(86362001)(81166006)(186003)(5660300002)(2906002)(102836004)(386003)(6506007);DIR:OUT;SFP:1102;SCL:1;SRVR:BYAPR15MB2600;H:BYAPR15MB2631.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1;
received-spf: None (protection.outlook.com: fb.com does not designate
 permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: psJ6PrpHs3gpw4eMzLKPubEKHR3aamKbYlMVlrNMCHHpC+mIv8M1WZ5MBYql4k8EnCzwcOb/tr2aIQuYsbVZ9L/YnZJqpGm8QhATxHXOtFhftaHmmCjadT3UU9CLJv+lTlF6laWLAcHzJujmZFUP0swUv0G4NAqUG/yNCoVrJgsAqPxPI2AsOoVfPFwzg+4d2UtwChDjFpaNerCX8z2mWTIv8ivLQk/L9dJLpVLvBowLd3e3+Yr2lN2HMrod+8WEI3AICfYV7S7ChSqyj82R9avYcyqo82OZ2T6R/QTCKAHay0fqFnxfuG/9xQwe5ykiAjjVLxz04r+JcHgoroEBPGghaNKnqZt4P0fnAMzUyWo6KNwq9nkz8CSESEeuS+IV/ewtnsqgowV0sTbOYcpHioGHzi5jIMqkRXoks7IeWRw=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <0EA21FF608EE45438385A171ACF79D9A@namprd15.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 9bab4133-a572-4471-8337-08d6e9f6d0b2
X-MS-Exchange-CrossTenant-originalarrivaltime: 05 Jun 2019 20:45:59.4688
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: guro@fb.com
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2600
X-OriginatorOrg: fb.com
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-05_13:,,
 signatures=0
X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501
 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0
 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0
 mlxlogscore=663 adultscore=0 classifier=spam adjust=0 reason=mlx
 scancount=1 engine=8.0.1-1810050000 definitions=main-1906050131
X-FB-Internal: deliver
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 Tue, Jun 04, 2019 at 09:14:18PM -0700, Andrew Morton wrote:
> On Tue, 4 Jun 2019 19:44:44 -0700 Roman Gushchin <guro@fb.com> wrote:
>=20
> > So instead of trying to find a maybe non-existing balance, let's do rep=
arent
> > the accounted slabs to the parent cgroup on cgroup removal.
>
> s/slabs/slab caches/.  Take more care with the terminology, please...

Slabs are effectively reparented too (what's most important, their
references), but I agree, "slab caches" suits better here.

>=20
> > There is a bonus: currently we do release empty kmem_caches on cgroup
> > removal, however all other are waiting for the releasing of the memory =
cgroup.
> > These refactorings allow kmem_caches to be released as soon as they
> > become inactive and free.
>=20
> Unclear.
>=20
> s/All other/releasing of all non-empty slab caches depends upon the relea=
sing/
>=20
> I think?
>=20
How about this?

There is a bonus: currently we release all memcg kmem_caches all together
with the memory cgroup itself. This patchset allows individual kmem_caches
to be released as soon as they become inactive and free.

--

Sorry, my bad, I was focused on patches, and didn't give enough attention
to the cover letter. I hope to get some feedback from Vladimir, and then
post a next version with these issues fixed.

Thank you for looking into it!

Roman