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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?obeUsOTYfOqAt5CVTNDszIqTiGPklYIAifG9Zo+5U0jMMKBabkNtd/3ejbt6?= =?us-ascii?Q?Hhso2MR9rZK+DHIL82QcB/ImS83RLy91F6ahaWrBV8jixmcQAmiGcsTzkmjO?= =?us-ascii?Q?nh8lCx1KhARcMGOSkyvGb8pkkXd5lvx4+8Fc95JZfxXBT7+bMmGcCUME9MCo?= =?us-ascii?Q?kpO7w/rkmzC3qU9+37qw+NvmPFIG4UH4SnC2aMgFeGCM03V+NHTgGs7+uti7?= =?us-ascii?Q?lwf//b8lImCGwU89McR5aokD/C2p5phLWPiOJhzuTp7ueg9cl8WJk2+bD9vo?= =?us-ascii?Q?YpfK988ltuQRhiaET8UiDonpqyIxI46n8ptGAihcQUc8gbq/7RcRSJAkqpmZ?= =?us-ascii?Q?4xADcyJNekm2EczORBCqx6AiIW4khkUy2BWo94onp4S/Zm0+wk8qgYK/Tipf?= =?us-ascii?Q?CA+mbWMEEtIhp4KjIUCS7ivygTJYnB4CC4idX2sSV0K6aJt+5AivMcpWPBDq?= =?us-ascii?Q?bE6Fnwlvq/ZDcIdiYufH497Rclf+kqRQkpod71RZuunQoxpOOfDcdN+2p/Hn?= =?us-ascii?Q?6RH5DEBLvL5EpjgnJIiTQp9Xdi5PJ0uUx9irS33H77StetNfCjI25L9BYXVD?= =?us-ascii?Q?WeWED7FwiKTPPH1BkFNgCDqn09jaiV5OfNOOkci5NK27kN/WEcdSmoHXuvrr?= =?us-ascii?Q?icNIJdooAFAorm100xP194wD3VtGj8eDyM9Qu5GqoagjAxFwo586FpVvNnQm?= =?us-ascii?Q?8dnuaaEcUcMTUprM4DYy45GpjrIGk75OGlGacunibOlx2vsg1tnafc++bNoq?= =?us-ascii?Q?lC/ZUVUjfeNr8JFHm4G83eT9x0P+cjPV2GadLGj5ESzGtzqJFf8br40/VpAC?= =?us-ascii?Q?r19ArYI8h9U/Fwnkl95PecVGjg9WIuRO5BpLOUEGp5m/ZnPcqqiCu1RlxrgG?= =?us-ascii?Q?YClIFrERp1owSDOrsJ8Qa1Fk065V3G5RfNm7ewiQEPipYjK1NSwcMk+7q43X?= =?us-ascii?Q?1iF0n8clWR+EQJzoDTDZgz6nbNt4MAdKX3DSo+0tRAW++fw+Yhs/oyJ9GAqH?= =?us-ascii?Q?ij6tbZzfNAi/1XWeJhFU5sO9Ye9PtpXwhDDz5am2EAjmU5B3EToUXt8LfNVV?= =?us-ascii?Q?0TTtOzgp/GyL/Jghptx2eOfgIXhAVSaJvAK5264dFj3/n05BlBQT1KXHI7bu?= =?us-ascii?Q?ywXNLCJthY3gwVR7dOo1f572XSmGRaQxzxRBXY/eYwxo635TjWh/W4Uuh79I?= =?us-ascii?Q?0b/u04rz0eDLdfuC346GVbFKntkbylng1fZ//scx/3s3kt51a89LptUR5IlX?= =?us-ascii?Q?h49M7LVitO+RjkFpWEcJbFd39zzo6rYBhCJkQoRvqkpZQ+Q7SEyLuyO8/GCg?= =?us-ascii?Q?So5E7sjG9lhvy0HC6+pkGaQjiMS6t9TLs6Bdq0U+690vM6U0KE0CBzhkhsj3?= =?us-ascii?Q?oNvNtedOhoMqY93iX1wTBM1iTiyVLybIHCQFmd3IZ9ThBSikX1f4rj291r95?= =?us-ascii?Q?oamO38h3cYcN/IfkU+IiHTm/mAUqp6ZsaiJljyosSm03d0r+wzdx9FocY5D5?= =?us-ascii?Q?QXi18FsAAA/X1KEZjxtiBUG8wWgiDVnvRXdpdJYv3TbTrfBD8368QmuUJhlG?= =?us-ascii?Q?7QnPXQJ0J85L97z0iwiSFiY1c9/9la7BKkBFyXDkwdfj9CsOdKZu03bXpvJ3?= =?us-ascii?Q?lt7GCZdkbzQwSbKHw84NKJ43Y6PRfddonUT9YmOLLoCfmW2DPRFM9KCESIV/?= =?us-ascii?Q?BjSbzQQlqFJ4MDrNRekU5g2SRxqY3FC6qg3n2Vi+bmZ3sVujHSbdjrjIFd+Q?= =?us-ascii?Q?n2+qimP+OQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 83c5308c-bdf7-4dda-9aa7-08df07fa4c61 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Sep 2026 07:26:11.6518 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: SQHxPrtIU/W8lQqKfyBt7kL2frHzwSDN512qCwtPSOtcmjMHW5k9nuRN9RjgChFxFHZUiLtYz+HIt1un7eZcug== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB8739 Hi Tao, On Tue, Sep 01, 2026 at 11:11:01AM +0800, Tao Cui wrote: > From: Tao Cui > > ops.cgroup_set_idle() is documented to be invoked when a cgroup > transitions between idle and non-idle states, and scx_group_set_weight() > already skips value-preserving writes. scx_group_set_idle() delivers > every write unconditionally, so rewriting an already-correct cpu.idle > value feeds the BPF scheduler a transition callback each time, which > toggle- or accounting-based schedulers miscount. Mirror the weight > guard and only deliver on an actual change. > > Verified with a probe scheduler printing each callback: rewriting > cpu.idle=1 twice on an already-idle cgroup delivered two callbacks > before and none after. > > Fixes: 347ed2d566da ("sched/ext: Implement cgroup_set_idle() callback") > Link: https://lore.kernel.org/r/b53c61a1-4d7d-4232-941f-d48b0563d4ed This link seems broken, I think the right one is: Link: https://lore.kernel.org/r/b53c61a1-4d7d-4232-941f-d48b0563d4ed@linux.dev > Signed-off-by: Tao Cui Other than that looks good to me. Reviewed-by: Andrea Righi Thanks, -Andrea > --- > kernel/sched/ext/ext.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c > index 8041c87a3562..8b3625107b72 100644 > --- a/kernel/sched/ext/ext.c > +++ b/kernel/sched/ext/ext.c > @@ -4933,7 +4933,8 @@ void scx_group_set_idle(struct task_group *tg, bool idle) > percpu_down_read(&scx_cgroup_ops_rwsem); > sch = scx_tg_knob_sched(tg); > > - if (scx_cgroup_enabled && sch && SCX_HAS_OP(sch, cgroup_set_idle)) > + if (scx_cgroup_enabled && sch && SCX_HAS_OP(sch, cgroup_set_idle) && > + tg->scx.sched_idle != idle) > SCX_CALL_OP(sch, cgroup_set_idle, NULL, tg_cgrp(tg), idle); > > /* Update the task group's idle state */ > -- > 2.43.0 >