Re: [PATCH 11/11] mm/damon: add damon_ctx->min_region

[SeongJae Park <sj@kernel.org>]

On Thu, 21 Aug 2025 18:51:59 +0800 Quanmin Yan <yanquanmin1@huawei.com> wrote:

> Adopting addr_unit would make DAMON_MINREGION 'addr_unit * 4096'
> bytes and cause data alignment issues[1].
> 
> Add damon_ctx->min_region to change DAMON_MIN_REGION from a global

s/min_region/min_sz_region/ ?

> macro value to per-context variable.
> 
> [1] https://lore.kernel.org/all/527714dd-0e33-43ab-bbbd-d89670ba79e7@huawei.com
> 
> Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
> ---
>  include/linux/damon.h        |  4 ++-
>  mm/damon/core.c              | 67 ++++++++++++++++++++----------------
>  mm/damon/sysfs.c             |  8 +++--
>  mm/damon/tests/core-kunit.h  | 21 ++++++-----
>  mm/damon/tests/vaddr-kunit.h |  2 +-
>  mm/damon/vaddr.c             |  2 +-
>  6 files changed, 61 insertions(+), 43 deletions(-)
[...]
> @@ -1248,6 +1253,7 @@ int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src)
>  	}
>  	dst->ops = src->ops;
>  	dst->addr_unit = src->addr_unit;
> +	dst->min_sz_region = max(DAMON_MIN_REGION / src->addr_unit, 1);

Can't we set this as src->min_sz_region?

I asked a same question[1] to the previous version but seems it was missed.

[...]

Other parts look good to me.

[1] https://lore.kernel.org/20250820215612.86678-1-sj@kernel.org


Thanks,
SJ