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

SeongJae Park
2026-03-07T02:40:39Z

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 …