Re: [RFC PATCH v3 0/7] DAMON based tiered memory management for CXL memory

[Honggyu Kim]

Hi SeongJae,

On Fri,  5 Apr 2024 12:28:00 -0700 SeongJae Park <sj@xxxxxxxxxx> wrote:
> Hello Honggyu,
> 
> On Fri,  5 Apr 2024 15:08:49 +0900 Honggyu Kim <honggyu.kim@xxxxxx> wrote:
> 
> > There was an RFC IDEA "DAMOS-based Tiered-Memory Management" previously
> > posted at [1].
> > 
> > It says there is no implementation of the demote/promote DAMOS action
> > are made.  This RFC is about its implementation for physical address
> > space.
> > 
> > 
> > Changes from RFC v2:
> >   1. Rename DAMOS_{PROMOTE,DEMOTE} actions to DAMOS_MIGRATE_{HOT,COLD}.
> >   2. Create 'target_nid' to set the migration target node instead of
> >      depending on node distance based information.
> >   3. Instead of having page level access check in this patch series,
> >      delegate the job to a new DAMOS filter type YOUNG[2].
> >   4. Introduce vmstat counters "damon_migrate_{hot,cold}".
> >   5. Rebase from v6.7 to v6.8.
> 
> Thank you for patiently keeping discussion and making this great version!  I
> left comments on each patch, but found no special concerns.  Per-page access
> recheck for MIGRATE_HOT and vmstat change are taking my eyes, though.  I doubt
> if those really needed.  It would be nice if you could answer to the comments.

I will answer them where you made the comments.

> Once my comments on this version are addressed, I would have no reason to
> object at dropping the RFC tag from this patchset.

Thanks.  I will drop the RFC after addressing your comments.

> Nonetheless, I show some warnings and errors from checkpatch.pl.  I don't
> really care about those for RFC patches, so no problem at all.  But if you
> agree to my opinion about RFC tag dropping, and therefore if you will send next
> version without RFC tag, please make sure you also run checkpatch.pl before
> posting.

Sure.  I will run checkpatch.pl from the next revision.

Thanks,
Honggyu

> 
> Thanks,
> SJ
> 
> [...]