Re: [PATCH v3] mm: remove min_free_kbytes adjustment for THP

[David Laight]

On Wed, 9 Sep 2026 12:18:03 +0100
"Lorenzo Stoakes (ARM)" <ljs@xxxxxxxxxx> wrote:

> On Wed, Sep 09, 2026 at 11:38:36AM +0100, David Laight wrote:
> > On Wed, 9 Sep 2026 09:11:04 +0100
> > "Lorenzo Stoakes (ARM)" <ljs@xxxxxxxxxx> wrote:
> >  
> > > On Tue, Sep 08, 2026 at 03:30:30PM -0400, Johannes Weiner wrote:  
> > > > On Tue, Sep 08, 2026 at 08:24:38AM -0400, Zi Yan wrote:  
> > > > > On Tue Sep 8, 2026 at 7:54 AM EDT, Vlastimil Babka (SUSE) wrote:  
> > > > > > Given neither of the patchset versions achieved universal acceptance, could
> > > > > > we try just disabling all the automatic (re)calculations of min_free_kbytes
> > > > > > the first moment the sysctl gets adjusted from userspace?  
> > > > >
> > > > > Sounds good to me. Johannes, WDYT?  
> > > >
> > > > +1 That sounds good to me as well.  
> > >
> > > Me also! :>)  
> >
> > You might want some method of restoring the default behaviour.
> > Maybe setting to 0 can be used (if that is just silly).  
> 
> I suppose the concern would be an embedded user for some reason enabling
> CONFIG_TRANSPARENT_HUGEPAGE and then defaulting to THP ->madvise and getting the
> bigger reserves before somehow disabling it after boot.

Or just testing whether it makes any difference to a workload.

David

> 
> But I'm not sure if this is something we really need to worry about?
> 
> >
> > David
> >  
> > >
> > > --
> > > Cheers, Lorenzo
> > >  
> >  
> 
> --
> Cheers, Lorenzo