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.
No functional changes applied.
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
---
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,
+};
+
+static unsigned long damon_pa_migrate(struct damon_region *r, struct damos *s,
+ enum migration_mode mm)
{
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)
put_folio:
folio_put(folio);
}
- applied = reclaim_pages(&folio_list);
+ switch (mm) {
+ case MIG_PAGEOUT:
+ applied = reclaim_pages(&folio_list);
+ break;
+ default:
+ /* Unexpected migration mode. */
+ return 0;
+ }
cond_resched();
return applied * PAGE_SIZE;
}
@@ -297,7 +309,7 @@ static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,
{
switch (scheme->action) {
case DAMOS_PAGEOUT:
- return damon_pa_pageout(r, scheme);
+ return damon_pa_migrate(r, scheme, MIG_PAGEOUT);
case DAMOS_LRU_PRIO:
return damon_pa_mark_accessed(r, scheme);
case DAMOS_LRU_DEPRIO:
--
2.34.1On Fri, 5 Apr 2024 15:08:50 +0900 Honggyu Kim <honggyu.kim@sk.com> 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.
>
> No functional changes applied.
>
> Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
> ---
> 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)
> put_folio:
> folio_put(folio);
> }
> - applied = reclaim_pages(&folio_list);
> + switch (mm) {
> + case MIG_PAGEOUT:
> + applied = reclaim_pages(&folio_list);
> + break;
> + default:
> + /* Unexpected migration mode. */
> + return 0;
> + }
> cond_resched();
> return applied * PAGE_SIZE;
> }
> @@ -297,7 +309,7 @@ static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,
> {
> switch (scheme->action) {
> case DAMOS_PAGEOUT:
> - return damon_pa_pageout(r, scheme);
> + return damon_pa_migrate(r, scheme, MIG_PAGEOUT);
> case DAMOS_LRU_PRIO:
> return damon_pa_mark_accessed(r, scheme);
> case DAMOS_LRU_DEPRIO:
> --
> 2.34.1
Thanks,
SJ
On Fri, 5 Apr 2024 12:19:07 -0700 SeongJae Park <sj@kernel.org> wrote:
> On Fri, 5 Apr 2024 15:08:50 +0900 Honggyu Kim <honggyu.kim@sk.com> 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@kernel.org
Thanks,
SJ
[...]
>
> >
> > No functional changes applied.
> >
> > Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
> > ---
> > 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
[...]
On Sat, 11 May 2024 13:16:17 -0700 SeongJae Park <sj@kernel.org> wrote: > On Fri, 5 Apr 2024 12:19:07 -0700 SeongJae Park <sj@kernel.org> wrote: > > > On Fri, 5 Apr 2024 15:08:50 +0900 Honggyu Kim <honggyu.kim@sk.com> 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@kernel.org I updated this patchset to address comments on this thread, and posted it as RFC patchset v4 on behalf of Honggyu under his approval: https://lore.kernel.org/20240512175447.75943-1-sj@kernel.org Thanks, SJ [...]
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