On Fri, 5 Apr 2024 12:19:07 -0700 SeongJae Park <sj@xxxxxxxxxx> wrote: > On Fri, 5 Apr 2024 15:08:50 +0900 Honggyu Kim <honggyu.kim@xxxxxx> wrote: > > > This is a preparation patch that introduces migration modes. > > > > The damon_pa_pageout is renamed to damon_pa_migrate and it receives an > > extra argument for migration_mode. > > I personally think keeping damon_pa_pageout() as is and adding a new function > (damon_pa_migrate()) with some duplicated code is also ok, but this approach > also looks fine to me. So I have no strong opinion here, but just letting you > know I would have no objection at both approaches. Meanwhile, we added one more logic in damon_pa_pageout() for doing page idleness double check on its own[1]. It makes reusing damon_pa_pageout() for multiple reason a bit complex. I think the complexity added a problem in this patch that I also missed before due to the complexity. Show below comment in line. Hence now I think it would be better to do the suggested way. If we use the approach, this patch is no more necessary, and therefore can be dropped. [1] https://lore.kernel.org/20240426195247.100306-1-sj@xxxxxxxxxx Thanks, SJ [...] > > > > > No functional changes applied. > > > > Signed-off-by: Honggyu Kim <honggyu.kim@xxxxxx> > > --- > > mm/damon/paddr.c | 18 +++++++++++++++--- > > 1 file changed, 15 insertions(+), 3 deletions(-) > > > > diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c > > index 081e2a325778..277a1c4d833c 100644 > > --- a/mm/damon/paddr.c > > +++ b/mm/damon/paddr.c > > @@ -224,7 +224,12 @@ static bool damos_pa_filter_out(struct damos *scheme, struct folio *folio) > > return false; > > } > > > > -static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s) > > +enum migration_mode { > > + MIG_PAGEOUT, > > +}; > > To avoid name conflicts, what about renaming to 'damos_migration_mode' and > 'DAMOS_MIG_PAGEOUT'? > > > + > > +static unsigned long damon_pa_migrate(struct damon_region *r, struct damos *s, > > + enum migration_mode mm) > > My poor brain has a bit confused with the name. What about calling it 'mode'? > > > { > > unsigned long addr, applied; > > LIST_HEAD(folio_list); > > @@ -249,7 +254,14 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s) Before this line, damon_pa_pageout() calls folio_clear_referenced() and folio_test_clear_young() for the folio, because this is pageout code. Changed function, damon_pa_migrate() is not only for cold pages but general migrations. Hence it should also be handled based on the migration mode, but not handled. I think this problem came from the increased complexity of this function. Hence I think it is better to keep damon_pa_pageout() as is and adding a new function for migration. Thanks, SJ [...]
