Re: [PATCH v4 14/16] timer: Implement the hierarchical pull model

[Frederic Weisbecker]

On Fri, Nov 04, 2022 at 03:57:35PM +0100, Anna-Maria Behnsen wrote:
> +/*
> + * Returns true, if there is nothing to be propagated to the next level
> + *
> + * @data->nextexp is reset to KTIME_MAX; it is reused for first global
> + * event which needs to be handled by migrator (in toplevel group)
> + *
> + * This is the only place where group event expiry value is set.
> + */
> +static bool tmigr_update_events(struct tmigr_group *group,
> +				struct tmigr_group *child,
> +				struct tmigr_walk *data)
> +{
> +	struct tmigr_event *evt, *first_childevt;
> +	bool walk_done;
> +	u64 nextexp;
> +
> +	if (child) {
> +		if (data->childstate.active)
> +			return true;
> +
> +		raw_spin_lock(&child->lock);
> +		raw_spin_lock_nested(&group->lock, SINGLE_DEPTH_NESTING);
> +
> +		first_childevt = tmigr_next_groupevt(child);
> +		nextexp = child->next_expiry;
> +		evt = &child->groupevt;
> +	} else {
> +		nextexp = data->nextexp;
> +
> +		/*
> +		 * Set @data->nextexp to KTIME_MAX; it is reused for first
> +		 * global event which needs to be handled by migrator (in
> +		 * toplevel group)
> +		 */
> +		data->nextexp = KTIME_MAX;
> +
> +		first_childevt = evt = data->evt;
> +		if (test_bit(0, &evt->ignore))

The bit 0 set/clear/test on that ignore field looks a bit confusing.
Is there any reason why it can't be some plain int/boolean?

Thanks.