Re: [PATCH] sched/ext: Add tg->scx.idle which tracks the current state

[Tejun Heo <tj@kernel.org>]

On Wed, Oct 08, 2025 at 10:09:39AM +0800, zhidao su wrote:
> Add an idle field to the scx_task_group structure to track the current
> idle state of a task group. This field is initialized to false in
> scx_tg_init() and updated in scx_group_set_idle() when the idle state
> changes.
> 
> This allows BPF schedulers to check the current idle state of a task
> group directly from the scx_task_group structure.
> 
> v2: Add tg->scx.idle which tracks the current state

Hmm... maybe a blank line here? I don't know whether there actually is an
established convention but I don't think we usually put version delta
descriptions in the tag section.

> Signed-off-by: zhidao su <soolaugust@gmail.com>
...
> @@ -4273,6 +4274,9 @@ void scx_group_set_idle(struct task_group *tg, bool idle)
>  
>  	percpu_down_read(&scx_cgroup_rwsem);
>  
> +	/* Update the task group's idle state */
> +	tg->scx.idle = idle;
> +
>  	if (scx_cgroup_enabled && SCX_HAS_OP(sch, cgroup_set_idle))
>  		SCX_CALL_OP(sch, SCX_KF_UNLOCKED, cgroup_set_idle, NULL,
>  			    tg_cgrp(tg), idle);

This can be either way but scx_group_set_weight() sets the weight after
calling the ops.cgroup_set_weight() is called, so let's match that.

Thanks.

-- 
tejun