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charset="iso-8859-1" Content-ID: <9251CA4EE47867469CA25AC1576D7DF2@namprd18.prod.outlook.com> Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Exchange-RoutingPolicyChecked: V7B6Cy9jae2bdQ9gFis7UYosZOoIa9YRj62lXmPbOHksg2v4g+DkYWo33AFLgqQUIvsLw99BiVAiNpkzhBl1itV48i7tSnm9L1ANkvVcGRauXtPuVSBKIq7LRu5Uhg19fRDlknnoKFasaRt7TnA0A8gUOKNl02vEenpyOCmoSUQ5cLln/TR7EoROSybC4Mi//iLN4mnQsVUdqTulNFpXoEc3xDdOB6oRVrFEWnexS9Ib6NTaEus/xLQ77kzzlTGtGh0YV74LPcslDZ1mSCB56gmVTiSdDy6vzxGLvw4oE7Wr5uXGh4bVvg8sfu++DkhepSf64Dkmr+L6gug0Da0DxQ== X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: MW4PR18MB5206.namprd18.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: ac268e9b-dcf6-469a-190e-08de94e3ae41 X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Apr 2026 20:24:33.4826 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 5280104a-472d-4538-9ccf-1e1d0efe8b1b X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: nR2/g58pgKMVZyhsjiqpgHg0Q3XY9SIWmxu2uLBJQiRxRJbWOgig5BcuNqOMqhOae0tRIVLlPFpfHc08/6LPag== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR18MB4800 X-OriginatorOrg: amazon.com On Tue, Apr 07, 2026 at 08:27:41AM -1000, Tejun Heo wrote: >On Mon, Apr 06, 2026 at 06:06:43PM -0700, Willy Barro Raffel wrote: >> Expose per-CPU subtree_bstat via a new cgroupfs file cpu.stat.percpu. >> Each line shows one CPU cumulative stats in io.stat-style key=3Dvalue >> format: >> >> cpu0 usage_usec=3D123 user_usec=3D45 system_usec=3D78 nice_usec=3D0 >> cpu1 usage_usec=3D456 user_usec=3D123 system_usec=3D333 nice_usec=3D0 >> >> This completes the interface left as a TODO in commit 7716f383a583 >> ("Merge tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kerne= l/git/tj/cgroup") >> which added per-CPU subtree_bstat but only exposed it via BPF/drgn. > >Given how quickly cpu count is increasing with 1k CPUs on common prod >machines not too far off, I'm not sure naively formatting output for every >possible CPU is desirable. > >Thanks. > >-- >tejun Good point. I can skip CPUs with zero stats in the output, i.e.: a cgroup r= unning on 4 of 1024 CPUs would only produce 4 lines. Would that address you= r concern?=