Re: [v2 RFC PATCH 0/9] Another Approach to Use PMEM as NUMA Node

From: Keith Busch
Date: Wed Apr 17 2019 - 11:47:24 EST


On Wed, Apr 17, 2019 at 05:39:23PM +0200, Michal Hocko wrote:
> On Wed 17-04-19 09:23:46, Keith Busch wrote:
> > On Wed, Apr 17, 2019 at 11:23:18AM +0200, Michal Hocko wrote:
> > > On Tue 16-04-19 14:22:33, Dave Hansen wrote:
> > > > Keith Busch had a set of patches to let you specify the demotion order
> > > > via sysfs for fun. The rules we came up with were:
> > >
> > > I am not a fan of any sysfs "fun"
> >
> > I'm hung up on the user facing interface, but there should be some way a
> > user decides if a memory node is or is not a migrate target, right?
>
> Why? Or to put it differently, why do we have to start with a user
> interface at this stage when we actually barely have any real usecases
> out there?

The use case is an alternative to swap, right? The user has to decide
which storage is the swap target, so operating in the same spirit.