[RFC PATCH v2 2/7] mm/damon/core: extend probe_hits_wsum() for moving sum based calculation

[SJ Park <sj@kernel.org>]

damon_probe_hits_wsum() is being called only in aggregation time.  In
future, it could also be used by DAMOS.  In this case, since DAMOS uses
its own apply_interval, it could be called in sampling time.  Then using
the not yet fully aggregated probe_hits could result in suboptimum
outcomes.  Extend damon_probe_hits_wsum() to get the weighted sum based
on moving sum to prepare the DAMOS usage.

Signed-off-by: SJ Park <sj@kernel.org>
---
 include/linux/damon.h | 2 +-
 mm/damon/core.c       | 8 ++++++--
 mm/damon/paddr.c      | 2 +-
 mm/damon/vaddr.c      | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 1deda16bb70b5..9fa99f92a2e94 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -1073,7 +1073,7 @@ unsigned int damon_nr_accesses_mvsum(struct damon_region *r,
 		struct damon_ctx *ctx);
 unsigned char damon_probe_hits_mvsum(int probe_idx, struct damon_region *r,
 		struct damon_ctx *ctx);
-unsigned int damon_probe_hits_wsum(struct damon_region *r, bool last,
+unsigned int damon_probe_hits_wsum(struct damon_region *r, bool last, bool mv,
 		struct damon_ctx *ctx);
 
 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 1752afede01e2..30af5bbcc90e7 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -469,11 +469,12 @@ static bool damon_is_last_region(struct damon_region *r,
  * damon_probe_hits_wsum() - Returns probe hits weighted sum of a region.
  * @r:		region to get the weighted sum of.
  * @last:	if the request is for last-window aggregated probe hits.
+ * @mv:		use moving sum.
  * @ctx:	context of &r.
  *
  * Return: the weighted sum of probe hits of the region.
  */
-unsigned int damon_probe_hits_wsum(struct damon_region *r, bool last,
+unsigned int damon_probe_hits_wsum(struct damon_region *r, bool last, bool mv,
 		struct damon_ctx *ctx)
 {
 	struct damon_probe *probe;
@@ -483,6 +484,9 @@ unsigned int damon_probe_hits_wsum(struct damon_region *r, bool last,
 	damon_for_each_probe(probe, ctx) {
 		if (last)
 			sum += r->last_probe_hits[i++] * probe->weight;
+		else if (mv)
+			sum += damon_probe_hits_mvsum(i++, r, ctx) *
+				probe->weight;
 		else
 			sum += r->probe_hits[i++] * probe->weight;
 	}
@@ -3467,7 +3471,7 @@ static unsigned int damon_merge_score(struct damon_region *r, bool last,
 		struct damon_ctx *ctx, bool use_probe_hits)
 {
 	if (use_probe_hits)
-		return damon_probe_hits_wsum(r, last, ctx);
+		return damon_probe_hits_wsum(r, last, false, ctx);
 	if (last)
 		return r->last_nr_accesses;
 	return r->nr_accesses;
diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index d7c81829445ba..b8f4d28165dd7 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -202,7 +202,7 @@ static unsigned int damon_pa_apply_probes(struct damon_ctx *ctx,
 				folio_put(folio);
 			if (return_max_wsum)
 				max_wsum = max(damon_probe_hits_wsum(r, false,
-							ctx), max_wsum);
+							false, ctx), max_wsum);
 		}
 	}
 	return max_wsum;
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 9a38dc89a156e..4aecf34e39be2 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -704,7 +704,7 @@ static unsigned int damon_va_apply_probes(struct damon_ctx *ctx,
 			__damon_va_apply_probes(ctx, mm, r);
 			if (return_max_wsum)
 				max_wsum = max(damon_probe_hits_wsum(r, false,
-							ctx), max_wsum);
+							false, ctx), max_wsum);
 		}
 		if (mm)
 			mmput(mm);
-- 
2.47.3