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=?utf-8?B?ZG0vYUdZcndKMFJtSDFWbFVnNU00bm8wQkFrMFVKM3huQy9VOHdXVVdLcUVi?= =?utf-8?Q?lcARqssfUVoGGpu4=3D?= X-Exchange-RoutingPolicyChecked: pk+R+P/dZYTWku6+D2IXX3gkTjEaIpG6LPCc68BkLym+0qq3RkXCTGTNrrgtIPlN5+mBf3fq3fC89yIXALYGAwHfsSvSH3vdSwt/LgrvaXRqWl990lC7OSfUWxzhWNHXAj52LEfnVEbrEkOQGeuA6BRUrjh4EUvX3wME2FydJ3hN7ZKlCCslfqnDGRPlnVgrXm0+lJmp1L7wk66ExPtosbB0PB2zlA/TWXTwsZfckTf1Z4Yc2O02dsp2Dv5vt8G/4wLl3hjDG31bGWNdZwRCwPh5pWd6CYcUGAiahpjSdwDdctSjpNfv6wdAg59lOYBy/EQRuHp/llZDWhW6MD+Bpg== X-MS-Exchange-CrossTenant-Network-Message-Id: 3ca27edd-c70b-4805-3c18-08dea9f67eb8 X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7573.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 May 2026 16:02:08.7898 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 6L40/D6z7RbmLnrunQT77yRLWvRNrQCoCmFuJ0LRamrHvM/f9qkP9vmTea7r+KHVFHMjfKAdTo1TjTHV4/h3cVUreALGXCfoAWkuFMxLtNs= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR11MB5878 X-OriginatorOrg: intel.com Hi Ben, On 4/28/26 6:04 AM, Ben Horgan wrote: > When 0 is written to the tasks file it is interpreted as the current task > in rdtgroup_move_task(). Each CPU's idle task has task_struct::pid set to 0 > and, on x86, task_struct::closid to RESCTRL_RESERVED_CLOSID and > task_struct::rmid to RESCTRL_RESERVED_RMID. Equivalently, on MPAM > platforms, thread_info::mpam_partid_pmg is encoded with PARTID and PMG set > to RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID, respectively. As > there is no interface to change these from the default, the resctrl > configuration for the idle tasks is fixed and they always behave > equivalently to a task in the default tasks file and so take their > configuration from the cpus/cpus_list files. > > On read of the tasks file, show_rdt_tasks() filters out any 0 PID. Hence, a > task id of 0 is never shown in the tasks file and the idle tasks are not > represented either. > > Document the user visible behaviour. > > Signed-off-by: Ben Horgan > --- Thank you very much for adding this. Reviewed-by: Reinette Chatre Reinette