Re: [RFC PATCH v2 11/17] sched: Basic tracking of matching tasks

From: Aaron Lu
Date: Mon Apr 29 2019 - 02:15:33 EST


On Tue, Apr 23, 2019 at 04:18:16PM +0000, Vineeth Remanan Pillai wrote:
> +/*
> + * Find left-most (aka, highest priority) task matching @cookie.
> + */
> +struct task_struct *sched_core_find(struct rq *rq, unsigned long cookie)
> +{
> + struct rb_node *node = rq->core_tree.rb_node;
> + struct task_struct *node_task, *match;
> +
> + /*
> + * The idle task always matches any cookie!
> + */
> + match = idle_sched_class.pick_task(rq);
> +
> + while (node) {
> + node_task = container_of(node, struct task_struct, core_node);
> +
> + if (node_task->core_cookie < cookie) {
> + node = node->rb_left;

Should go right here?

> + } else if (node_task->core_cookie > cookie) {
> + node = node->rb_right;

And left here?

> + } else {
> + match = node_task;
> + node = node->rb_left;
> + }
> + }
> +
> + return match;
> +}