Re: retiring laptop_mode? was Re: [PATCH] mm: vmscan: always allow writeback during memcg reclaim

Shakeel Butt
2025-12-18T07:21:15Z

On Wed, Dec 17, 2025 at 02:59:20PM -0500, Johannes Weiner wrote:
> On Tue, Dec 16, 2025 at 03:23:53PM -0800, Shakeel Butt wrote:
> > On Tue, Dec 16, 2025 at 01:52:01PM -0500, Johannes Weiner wrote:
>
> > Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
>
> Thanks!
>
> > > --- a/include/uapi/linux/sysctl.h
> > > +++ b/include/uapi/linux/sysctl.h
> > > @@ -183,7 +183,7 @@ enum
> > > VM_LOWMEM_RESERVE_RATIO=20,/* reservation ratio for lower memory zones */
> > > VM_MIN_FREE_KBYTES=21, /* Minimum free kilobytes to maintain */
> > > VM_MAX_MAP_COUNT=22, /* int: Maximum number of mmaps/address-space */
> > > - VM_LAPTOP_MODE=23, /* vm laptop mode */
> > > +
> >
> > There are 8 earlier enums here with names like VM_UNUSED* along with
> > the information on what were they. Should we have something similar for
> > this one? Something like:
> >
> > VM_UNUSED10=23, /* was vm laptop mode */
>
> The other enums in that file leave holes, the VM ones have a mix of
> VM_UNUSED and holes. I don't think it matters either way since the
> sysctl syscall has been removed and nothing new should be compiled
> against the definitions in this file, right?

Yes, you are right.