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mx.microsoft.com 1; spf=pass smtp.mailfrom=nutanix.com; dmarc=pass action=none header.from=nutanix.com; dkim=pass header.d=nutanix.com; arc=none Received: from MN2PR02MB6303.namprd02.prod.outlook.com (2603:10b6:208:1bd::13) by MN2PR02MB6989.namprd02.prod.outlook.com (2603:10b6:208:20f::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2921.25; Tue, 14 Apr 2020 16:08:39 +0000 Received: from MN2PR02MB6303.namprd02.prod.outlook.com ([fe80::1dc5:77f3:3eaf:ffc8]) by MN2PR02MB6303.namprd02.prod.outlook.com ([fe80::1dc5:77f3:3eaf:ffc8%4]) with mapi id 15.20.2900.028; Tue, 14 Apr 2020 16:08:39 +0000 From: Ivan Teterevkov To: Michal Hocko CC: "rientjes@google.com" , "willy@infradead.org" , "vbabka@suse.cz" , "tj@kernel.org" , "lizefan@huawei.com" , "hannes@cmpxchg.org" , "corbet@lwn.net" , "vdavydov.dev@gmail.com" , "akpm@linux-foundation.org" , "guro@fb.com" , "shakeelb@google.com" , "chris@chrisdown.name" , "yang.shi@linux.alibaba.com" , "tglx@linutronix.de" , "minchan@kernel.org" , "ying.huang@intel.com" , "ziqian.lzq@antfin.com" , "cgroups@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Jonathan Davies Subject: RE: [RFC] memcg: fix default behaviour of non-overridden memcg.swappiness Thread-Topic: [RFC] memcg: fix default behaviour of non-overridden memcg.swappiness Thread-Index: AdX+Dc7TuUU65jcsTmmN9pfGvp9AeQAr94MABO48HRA= Date: Tue, 14 Apr 2020 16:08:39 +0000 Message-ID: References: <20200320134428.GG24409@dhcp22.suse.cz> In-Reply-To: <20200320134428.GG24409@dhcp22.suse.cz> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [31.125.170.138] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 5e2c41af-10e4-40dd-05a3-08d7e08e187c x-ms-traffictypediagnostic: MN2PR02MB6989: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-proofpoint-crosstenant: true x-ms-oob-tlc-oobclassifiers: OLM:9508; x-forefront-prvs: 0373D94D15 x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MN2PR02MB6303.namprd02.prod.outlook.com;PTR:;CAT:NONE;SFTY:;SFS:(10019020)(136003)(396003)(39830400003)(376002)(346002)(366004)(44832011)(5660300002)(2906002)(8676002)(86362001)(478600001)(71200400001)(4744005)(33656002)(81156014)(8936002)(26005)(107886003)(54906003)(316002)(6916009)(4326008)(186003)(6506007)(66556008)(66476007)(7416002)(76116006)(52536014)(9686003)(66446008)(66946007)(64756008)(7696005)(55016002);DIR:OUT;SFP:1102; received-spf: None (protection.outlook.com: nutanix.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 81fjC7P1yUMgY4+NpwMHI7pjn64+1RSsVdFiC63I2EjZYQbX8lBwmNU7DEdyHwfIflKXfLb+a0FrJbPvp7pE60U/FMcVzmqTGAxfpBRBUPbPLYOXKkkVryPhctMY+dTsII+QL66+zXKr0LB3NEdnG88v5xDMx/jEL7pZyaA8R0dElqLncU6RVjGVJ6Kes3ugmg0q/xUR133kE9bf0dEAL2dr1zJOgPWl9nakO/WANWVw7+3POwl+rIkamaAotUH5KDyycsv61hN0EYm14kBNs5kQn+J6KUvPLS0A4bpLrUHRmqT3bZ8xfS6OtYvq2YEsFFsBYJq7E+Lf0Kp77xSjEBCh2hb25SAiIVCTWNt6CyAnrxESnO0igeMiAcC9OrtW074jirVAVZ9vW+XTqipmh/Z+TGDjek6ryaEHOJaGE0c/uoHE5N5IRKkGOHpdRKZc x-ms-exchange-antispam-messagedata: PrOqkpWRb9Lmx1mGa2XnylOJJ2/L1K4/mKxs21Cukmg4Wxva66c+exnxyQwDNQXu5lV/zyxZW3rn/9iha0pLf+xw5WL4w9rct+sxamv9I59p/gobmZV7Q/BzEOluJ1ye5fTYPzML0X9HH6AU3wrv1Q== Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nutanix.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5e2c41af-10e4-40dd-05a3-08d7e08e187c X-MS-Exchange-CrossTenant-originalarrivaltime: 14 Apr 2020 16:08:39.4265 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: bb047546-786f-4de1-bd75-24e5b6f79043 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: aAGl/A2ez2HORvWec3Er0IHF+Gsn+A2FgN90jguyi/fbSkLzjhQa7NfR2/Iudr+hXn9hbm8gWjdp3Eha+S1mEjv+Sx0Mm2PlpY12YIa5E+g= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR02MB6989 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-14_09:2020-04-14,2020-04-14 signatures=0 X-Proofpoint-Spam-Reason: safe Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Mar 2020, Michal Hocko wrote: > On Thu 19-03-20 17:38:30, Ivan Teterevkov wrote: > > Also, shall this magic -1 be exposed to the user? I think it's a "no", > > but what if the user wants to un-override the memcg.swappiness... >=20 > If we are to use such a semantic then it absolutely has to be an opt-in b= ehavior > and expressed in some way to the user space (e.g. a symbolic name referri= ng to > the global setting). A symbolic link would be a good approach but... > I am not convinced we need it. ... agree and not going any further with the suggestion. Support of the sysctl parameters in the kernel command line is a better solution and would address my initially raised concern to tackle the configuration parameters. Thanks Ivan