Re: [RFC PATCH v2 01/10] mm/damon/core: introduce damos_quota_goal_tuner

[SeongJae Park <sj@kernel.org>]

On Tue,  3 Mar 2026 20:41:10 -0800 SeongJae Park <sj@kernel.org> wrote:

> Currently DAMOS quota goal feature utilizes a single feedback loop based
> algorithm for automatic tuning of the effective quota.  It is useful in
> dynamic environments that operate systems with only kernels in the long
> term.  But, no one fits all.  It is not very easy to control in
> environments having more controlled characteristics and user-space
> control towers.  We actually got multiple reports [1,2] of use cases
> that the algorithm is not optimal.
> 
> Introduce a new field of 'struct damos_quotas', namely 'goal_tuner'.  It
> specifies what tuning algorithm the given scheme should use, and allows
> DAMON API callers to set it as they want.  Nonetheless, this commit
> introduces no new tuning algorithm but only the interface.  This commit
> hence makes no behavioral change.  A new algorithm will be added by the
> following commit.
> 
> [1] https://lore.kernel.org/CALa+Y17__d=ZsM1yX+MXx0ozVdsXnFqF4p0g+kATEitrWyZFfg@mail.gmail.com
> [2] https://lore.kernel.org/20260204022537.814-1-yunjeong.mun@sk.com
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
[...]
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
[...]
>  /**
>   * struct damos_quota - Controls the aggressiveness of the given scheme.
>   * @reset_interval:	Charge reset interval in milliseconds.
> @@ -260,6 +268,7 @@ struct damos_quota {
>  	unsigned long ms;
>  	unsigned long sz;
>  	struct list_head goals;
> +	enum damos_quota_goal_tuner goal_tuner;

And the above change is not updating the kernel-doc comment of this struct.
I'll add that in the next spin.


Thanks,
SJ

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