Re: [PATCH 08/11] mm/damon/lru_sort: support active:inactive memory ratio based auto-tuning

[wang lian <lianux.mm@gmail.com>]

> Doing DAMOS_LRU_[DE]PRIO with DAMOS_QUOTA_[IN]ACTIVE_MEM_BP based quota
> auto-tuning can be easy and intuitive, compared to the manual
> [de]prioritization target access pattern thresholds tuning.  For
> example, users can ask DAMON to "find hot/cold pages and
> activate/deactivate those aiming 50:50 active:inactive memory size." But
> DAMON_LRU_SORT has no interface to do that.  Add a module parameter for
> setting the target ratio.

> Signed-off-by: SeongJae Park <sj@kernel.org>

```
> +static int damon_lru_sort_add_quota_goals(struct damos *hot_scheme,
> +		struct damos *cold_scheme)
> +{
> 	struct damos_quota_goal *goal;
> +
> +	if (!active_mem_bp)
> +		return 0;
> +	goal = damos_new_quota_goal(DAMOS_QUOTA_ACTIVE_MEM_BP, active_mem_bp);
> +	if (!goal)
> +		return -ENOMEM;
> +	damos_add_quota_goal(&hot_scheme->quota, goal);
> +	/* aim 0.2 % goal conflict, to keep little ping pong */
> +	goal = damos_new_quota_goal(DAMOS_QUOTA_INACTIVE_MEM_BP,
> +			10000 - active_mem_bp + 2);
> +	if (!goal)
> +		return -ENOMEM;
> +	damos_add_quota_goal(&hot_scheme->quota, goal);
> +	return 0;
> +}

The second goal (Inactive ratio target) is added to hot_scheme again. 
Should this be cold_scheme? Currently the cold_scheme parameter appears to be unused.

--
Best Regards,
wang lian