On Tue, Nov 17, 2020 at 06:19:52PM -0500, Joel Fernandes (Google) wrote:
> +void sched_core_tag_requeue(struct task_struct *p, unsigned long cookie,
> bool group)
> +{
> + if (!p)
> + return;
> +
> + if (group)
> + p->core_group_cookie = cookie;
> + else
> + p->core_task_cookie = cookie;
> +
> + /* Use up half of the cookie's bits for task cookie and remaining for
> group cookie. */
> + p->core_cookie = (p->core_task_cookie <<
> + (sizeof(unsigned long) * 4)) +
> p->core_group_cookie;
This seems dangerous; afaict there is nothing that prevents cookie
collision.
