Re: [RFC PATCH 1/5] mm/damon/core: add damon_target->obsolete for pin-point removal

[SeongJae Park <sj@kernel.org>]

On Fri, 17 Oct 2025 09:52:16 -0500 Bijan Tabatabai <bijan311@gmail.com> wrote:

> Thanks for working on this SJ!

My pleasure!

> 
> On Thu, Oct 16, 2025 at 4:47 PM SeongJae Park <sj@kernel.org> wrote:
> >
> > DAMON's monitoring targets parameters update function,
> > damon_commit_targets(), is not providing a way to remove a target in the
> > middle of existing targets list.  Extend the API by adding a field to
> > struct damon_target.  If the field of a damon_commit_targets() source
> > target is set, it indicates the matcing target on the existing targets
> > list is obsolete.  damon_commit_targets() understands that and remove
> > those from the list, while respecting the index based matching for other
> > non-obsolete targets.
> >
> > Signed-off-by: SeongJae Park <sj@kernel.org>
> > ---
> >  include/linux/damon.h |  6 ++++++
> >  mm/damon/core.c       | 10 +++++++++-
> >  2 files changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/damon.h b/include/linux/damon.h
> > index 524dea87cac7..8a7b45b9e40d 100644
> > --- a/include/linux/damon.h
> > +++ b/include/linux/damon.h
> > @@ -92,17 +92,23 @@ struct damon_region {
> >   * @nr_regions:                Number of monitoring target regions of this target.
> >   * @regions_list:      Head of the monitoring target regions of this target.
> >   * @list:              List head for siblings.
> > + * @obsolete:          Whether the commit destination target is obsolete.
> >   *
> >   * Each monitoring context could have multiple targets.  For example, a context
> >   * for virtual memory address spaces could have multiple target processes.  The
> >   * @pid should be set for appropriate &struct damon_operations including the
> >   * virtual address spaces monitoring operations.
> > + *
> > + * @obsolte is used only for damon_commit_targets() source targets, to specify
> > + * the matching destination targets are obsolte.  Read damon_commit_targets()
> > + * to see how it is handled.
> >   */
> Nit: Twice in the above comment you've written "obsolte" instead of "obsolete."

Thank you for catching this, I will definitely fix those on the next spin.

> 
> With that fixed
> Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
> for the entire series.

Thank you!


Thanks,
SJ

[...]