Re: [PATCH 03/15] sched_ext: Factor out pnode allocation and deallocation into helpers

[Emil Tsalapatis]

On Fri Mar 6, 2026 at 2:06 PM EST, Tejun Heo wrote:
> Extract pnode allocation and deallocation logic into alloc_pnode() and
> free_pnode() helpers. This simplifies scx_alloc_and_add_sched() and prepares
> for adding more per-node initialization and cleanup in subsequent patches.
>
> No functional changes.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>

Reviewed-by: Emil Tsalapatis <emil@xxxxxxxxxxxxxxx>

> ---
>  kernel/sched/ext.c | 32 +++++++++++++++++++++++---------
>  1 file changed, 23 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index 9232abea4f22..c36d399bca3e 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -4114,6 +4114,7 @@ static const struct attribute_group scx_global_attr_group = {
>  	.attrs = scx_global_attrs,
>  };
>  
> +static void free_pnode(struct scx_sched_pnode *pnode);
>  static void free_exit_info(struct scx_exit_info *ei);
>  
>  static void scx_sched_free_rcu_work(struct work_struct *work)
> @@ -4148,7 +4149,7 @@ static void scx_sched_free_rcu_work(struct work_struct *work)
>  	free_percpu(sch->pcpu);
>  
>  	for_each_node_state(node, N_POSSIBLE)
> -		kfree(sch->pnode[node]);
> +		free_pnode(sch->pnode[node]);
>  	kfree(sch->pnode);
>  
>  	rhashtable_walk_enter(&sch->dsq_hash, &rht_iter);
> @@ -5685,6 +5686,24 @@ static int alloc_kick_syncs(void)
>  	return 0;
>  }
>  
> +static void free_pnode(struct scx_sched_pnode *pnode)
> +{
> +	kfree(pnode);
> +}
> +
> +static struct scx_sched_pnode *alloc_pnode(struct scx_sched *sch, int node)
> +{
> +	struct scx_sched_pnode *pnode;
> +
> +	pnode = kzalloc_node(sizeof(*pnode), GFP_KERNEL, node);
> +	if (!pnode)
> +		return NULL;
> +
> +	init_dsq(&pnode->global_dsq, SCX_DSQ_GLOBAL, sch);
> +
> +	return pnode;
> +}
> +
>  static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops,
>  						 struct cgroup *cgrp,
>  						 struct scx_sched *parent)
> @@ -5714,16 +5733,11 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops,
>  	}
>  
>  	for_each_node_state(node, N_POSSIBLE) {
> -		struct scx_sched_pnode *pnode;
> -
> -		pnode = kzalloc_node(sizeof(*pnode), GFP_KERNEL, node);
> -		if (!pnode) {
> +		sch->pnode[node] = alloc_pnode(sch, node);
> +		if (!sch->pnode[node]) {
>  			ret = -ENOMEM;
>  			goto err_free_pnode;
>  		}
> -
> -		init_dsq(&pnode->global_dsq, SCX_DSQ_GLOBAL, sch);
> -		sch->pnode[node] = pnode;
>  	}
>  
>  	sch->dsp_max_batch = ops->dispatch_max_batch ?: SCX_DSP_DFL_MAX_BATCH;
> @@ -5821,7 +5835,7 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops,
>  	free_percpu(sch->pcpu);
>  err_free_pnode:
>  	for_each_node_state(node, N_POSSIBLE)
> -		kfree(sch->pnode[node]);
> +		free_pnode(sch->pnode[node]);
>  	kfree(sch->pnode);
>  err_free_hash:
>  	rhashtable_free_and_destroy(&sch->dsq_hash, NULL, NULL);