[PATCH 14/19] mm/damon/core: get merge threshold from probe hits when weights are set

[SJ Park <sj@kernel.org>]

When probe weights are set, DAMON merges regions based on their probe
hits weighted sum.  But the merge threshold is calculated based on the
access frequency.  Update it to retrieve the maximum probe hits weighted
sum in the snapshot from apply_probes() ops callback, and generate the
threshold based on it.

Signed-off-by: SJ Park <sj@kernel.org>
---
 mm/damon/core.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index f7782c69037da..91964336ce31e 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3763,7 +3763,8 @@ static int kdamond_fn(void *data)
 		unsigned long next_ops_update_sis = ctx->next_ops_update_sis;
 		unsigned long sample_interval = ctx->attrs.sample_interval;
 		bool access_check_disabled = damon_has_probe_weights(ctx);
-		unsigned int max_merge_score = 0;
+		unsigned int max_merge_score = 0, max_wsum;
+		bool get_max_wsum;
 
 		if (kdamond_wait_activation(ctx))
 			break;
@@ -3776,9 +3777,18 @@ static int kdamond_fn(void *data)
 
 		if (!access_check_disabled && ctx->ops.check_accesses)
 			max_merge_score = ctx->ops.check_accesses(ctx);
-		if (ctx->ops.apply_probes)
-			ctx->ops.apply_probes(ctx, access_check_disabled,
-					false);
+		if (ctx->ops.apply_probes) {
+			if (time_after_eq(ctx->passed_sample_intervals,
+						next_aggregation_sis) &&
+					access_check_disabled)
+				get_max_wsum = true;
+			else
+				get_max_wsum = false;
+			max_wsum = ctx->ops.apply_probes(ctx,
+					access_check_disabled, get_max_wsum);
+			if (get_max_wsum)
+				max_merge_score = max_wsum;
+		}
 
 		if (time_after_eq(ctx->passed_sample_intervals,
 					next_aggregation_sis)) {
-- 
2.47.3