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received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-microsoft-antispam-message-info: WY5U90tKQNM4yiWODoAT6d1MPFs/cavAGTZXeJd+lZFJm8gH/UBcbRh1M+J8km5ykJuS0Gj0tq0KcLPcckNJsZ09E/13ql2AqH/LyXUQmPKGFhfLpJUiZj0Qs4C2dQY8sSM1MlmV0B2/T9+lBJLHia+zBk+m8LVGeTD5RNXMe/+iTnGpPDbYBfoi0TT5+wIgYCYtnpxmYJ1qRpxUd+bhAFmCyzaJBo0PlaG/tdT4N5o2NWfYNLjzjmDcqceCa10nLJJRCP65jpM7FBjAflSLH0BO/ovjKKuOj5z5ZAjOwAwVz0Qe00chPRPbLTjsHtl+mE64Td6CNPlnU75eR5crptzOHVs16XFeULY477tJUyA= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="us-ascii" Content-ID: <2BFDF386C6DA804C8707CAE220CD369C@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: ed0a4ab3-1041-4ad7-062c-08d6594884a0 X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Dec 2018 17:55:32.2445 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY2PR15MB0309 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-12-03_09:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 03, 2018 at 08:17:06AM -0800, Tejun Heo wrote: > On Fri, Nov 30, 2018 at 03:47:41PM -0800, Roman Gushchin wrote: > > + * nr_descendants and nr_dying_descendants are protected > > + * by cgroup_mutex and css_set_lock. >=20 > Can you be a bit more specific - hold both for writes, either for > reads. Sure. Thanks!