Re: [PATCH] mm/Kconfig: allow user to select MIGRATION if MEMORY_FAILURE is enabled

On Wed, Aug 12, 2026 at 01:45:30PM +0300, Mike Rapoport wrote:
> Hi,
>
> On Wed, Aug 12, 2026 at 05:16:44PM +0800, Xie Yuanbin wrote:
> > Currently, memory-failure can be enabled without migration. However,
> > migration cannot be selected by user when memory-failure is enabled.
> >
> > Migration is very useful for soft_offline_page(), which may be triggered
> > by correctable memory errors. Most of the anonymous or file-mapping
> > faulty pages can be migrated to other healthy pages.
> >
> > Allow user to select MIGRATION if MEMORY_FAILURE is enabled.
> > Also, select MIGRATION by default if MEMORY_FAILURE is enabled.
>
> Do we want to make users decide if they need MIGRATION when MEMORY_FAILURE
> is enabled?
>
> Just make MEMORY_FAILURE select MIGRATION.

NO.

Explain first why the hell one of the other options that selection migration
can't be enabled.

Changing configs just to support a weirdo no to compaction but yes to doing soft
offline for debugging or whatever isn't really convincing unless a real world,
sensible use case can be stated.

The kernel isn't there to allow you to have broken configs.

>
> > Signed-off-by: Xie Yuanbin <[email protected]>
> > ---
> >  mm/Kconfig | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/mm/Kconfig b/mm/Kconfig
> > index 8a24c130d008..b4c217383b51 100644
> > --- a/mm/Kconfig
> > +++ b/mm/Kconfig
> > @@ -682,7 +682,8 @@ config NUMA_MIGRATION
> >  	  demotion for memory tiering.
> >
> >  config MIGRATION
> > -	bool
> > +	bool "Enable page migration" if MEMORY_FAILURE
> > +	default y if MEMORY_FAILURE
> >  	depends on MMU
> >
> >  config DEVICE_MIGRATION
> > --
> > 2.55.0
> >
>
> --
> Sincerely yours,
> Mike.

--
Cheers, Lorenzo