Re: [RFC PATCH v2 1/4] mm/damon: Generic context creation for modules

SeongJae Park
2026-03-11T00:58:07Z

On Tue, 10 Mar 2026 16:24:17 +0000 <gutierrez.asier@huawei-partners.com> wrote:

> From: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
>
> It is more elegant to have a generic version of new context creation
> which receives the mode as a parameter.
>
> Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
> Co-developed-by: Anatoly Stepanov <stepanov.anatoly@huawei.com>
> ---
> mm/damon/lru_sort.c | 5 +++--
> mm/damon/modules-common.c | 6 +++---
> mm/damon/modules-common.h | 4 ++--
> mm/damon/reclaim.c | 5 +++--
> 4 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
> index 7bc5c0b2aea3..143ee0b21da6 100644
> --- a/mm/damon/lru_sort.c
> +++ b/mm/damon/lru_sort.c
> @@ -287,7 +287,8 @@ static int damon_lru_sort_apply_parameters(void)
> unsigned int hot_thres, cold_thres;
> int err;
>
> - err = damon_modules_new_paddr_ctx_target(&param_ctx, &param_target);
> + err = damon_modules_new_ctx_target(&param_ctx, &param_target,
> + DAMON_OPS_PADDR);

I like the name of the function is becoming shorter. But I'm not happy with
the fact the resulting calling code becomes longer.

I understand you are doing this extension because you want a version of the
function for vaddr. What about introducing another dedicated function, say,
damon_modules_new_vaddr_ctx_target() ?

And you can avoid duplicates between damon_modules_new_{p,v}addr_ctx_target()
by implementing internal function, say, damon_modules_new_ctx_target() that
receives the damon_ops_id. And damon_modules_new_{P,v}addr_ctx_target() will
just wrappers of damon_modules_new_ctx_target().

> if (err)
> return err;
>
> @@ -479,7 +480,7 @@ static int __init damon_lru_sort_init(void)
> err = -ENOMEM;
> goto out;
> }
> - err = damon_modules_new_paddr_ctx_target(&ctx, &target);
> + err = damon_modules_new_ctx_target(&ctx, &target, DAMON_OPS_PADDR);

Ditto.

> if (err)
> goto out;
>
> diff --git a/mm/damon/modules-common.c b/mm/damon/modules-common.c
> index 86d58f8c4f63..ae50b2fa3a86 100644
> --- a/mm/damon/modules-common.c
> +++ b/mm/damon/modules-common.c
> @@ -14,8 +14,8 @@
> * @ctxp: Pointer to save the point to the newly created context
> * @targetp: Pointer to save the point to the newly created target
> */
> -int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
> - struct damon_target **targetp)
> +int damon_modules_new_ctx_target(struct damon_ctx **ctxp,
> + struct damon_target **targetp, enum damon_ops_id mode)

Nit. I'd suggest 'ops_id' as the parameter name, instead of 'mode'.

> {
> struct damon_ctx *ctx;
> struct damon_target *target;
> @@ -24,7 +24,7 @@ int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
> if (!ctx)
> return -ENOMEM;
>
> - if (damon_select_ops(ctx, DAMON_OPS_PADDR)) {
> + if (damon_select_ops(ctx, mode)) {
> damon_destroy_ctx(ctx);
> return -EINVAL;
> }
> diff --git a/mm/damon/modules-common.h b/mm/damon/modules-common.h
> index f103ad556368..379b49c6a617 100644
> --- a/mm/damon/modules-common.h
> +++ b/mm/damon/modules-common.h
> @@ -45,5 +45,5 @@
> module_param_named(nr_##qt_exceed_name, stat.qt_exceeds, ulong, \
> 0400);
>
> -int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
> - struct damon_target **targetp);
> +int damon_modules_new_ctx_target(struct damon_ctx **ctxp,
> + struct damon_target **targetp, enum damon_ops_id mode);
> diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
> index 43d76f5bed44..24786a58683a 100644
> --- a/mm/damon/reclaim.c
> +++ b/mm/damon/reclaim.c
> @@ -197,7 +197,8 @@ static int damon_reclaim_apply_parameters(void)
> struct damos_filter *filter;
> int err;
>
> - err = damon_modules_new_paddr_ctx_target(&param_ctx, &param_target);
> + err = damon_modules_new_ctx_target(&param_ctx, &param_target,
> + DAMON_OPS_PADDR);
> if (err)
> return err;
>
> @@ -381,7 +382,7 @@ static int __init damon_reclaim_init(void)
> err = -ENOMEM;
> goto out;
> }
> - err = damon_modules_new_paddr_ctx_target(&ctx, &target);
> + err = damon_modules_new_ctx_target(&ctx, &target, DAMON_OPS_PADDR);
> if (err)
> goto out;
>
> --
> 2.43.0

Thanks,
SJ