As of this writing, multiple major distros including Alma, Amazon,
Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON
(set CONFIG_DAMON[1]).  Enabling it by default will save configuration
setup time for the current and future DAMON users.

Build-enabling DAMON does not introduce a real risk since it makes no
behavioral change by default.  It requires explicit user requests to do
anything.  Only one potential risk is making the size of the kernel a
little bit larger.  On a production-purpose configuration, it increases
the resulting kernel package size by about 0.1 % of the final package
file.  I believe that's too small to be a real problem in common setups.

Hence, the benefit of enabling CONFIG_DAMON outweighs the potential
risk.  Set CONFIG_DAMON by default.

[1] https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index c93d0c56b963..551745df011b 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -4,6 +4,7 @@ menu "Data Access Monitoring"
 
 config DAMON
 	bool "DAMON: Data Access Monitoring Framework"
+	default y
 	help
 	  This builds a framework that allows kernel subsystems to monitor
 	  access frequency of each memory region. The information can be useful
-- 
2.39.5

On 5/21/2025 1:27 PM, SeongJae Park wrote:
> As of this writing, multiple major distros including Alma, Amazon,
> Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON
> (set CONFIG_DAMON[1]).  Enabling it by default will save configuration
> setup time for the current and future DAMON users.
> 
> Build-enabling DAMON does not introduce a real risk since it makes no
> behavioral change by default.  It requires explicit user requests to do
> anything.  Only one potential risk is making the size of the kernel a
> little bit larger.  On a production-purpose configuration, it increases
> the resulting kernel package size by about 0.1 % of the final package
> file.  I believe that's too small to be a real problem in common setups.
> 
> Hence, the benefit of enabling CONFIG_DAMON outweighs the potential
> risk.  Set CONFIG_DAMON by default.

Agreed.

> [1] https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>   mm/damon/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
> index c93d0c56b963..551745df011b 100644
> --- a/mm/damon/Kconfig
> +++ b/mm/damon/Kconfig
> @@ -4,6 +4,7 @@ menu "Data Access Monitoring"
>   
>   config DAMON
>   	bool "DAMON: Data Access Monitoring Framework"
> +	default y
>   	help
>   	  This builds a framework that allows kernel subsystems to monitor
>   	  access frequency of each memory region. The information can be useful

     Acked-by: Honggyu Kim <honggyu.kim@sk.com>

Thanks,
Honggyu