[RFC PATCH 11/13] mm/damon/core: remove nr_accesses_bp setups and updates
From: SeongJae Park
Date: Fri Jun 19 2026 - 15:39:39 EST
DAMON core sets and updates nr_accesses_bp in multiple places. It
explains how delicate it is. The field is no more being used for any
real purpose, and replaced by a simpler function. Remove the setups and
updates.
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
mm/damon/core.c | 17 -----------------
1 file changed, 17 deletions(-)
diff --git a/mm/damon/core.c b/mm/damon/core.c
index f2db39aa34f4c..eb129e3f7029d 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -294,7 +294,6 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end)
region->ar.start = start;
region->ar.end = end;
region->nr_accesses = 0;
- region->nr_accesses_bp = 0;
for (i = 0; i < DAMON_MAX_PROBES; i++)
region->probe_hits[i] = 0;
INIT_LIST_HEAD(®ion->list);
@@ -869,7 +868,6 @@ static void damon_update_monitoring_result(struct damon_region *r,
if (!aggregating) {
r->nr_accesses = damon_nr_accesses_for_new_attrs(
r->nr_accesses, old_attrs, new_attrs);
- r->nr_accesses_bp = r->nr_accesses * 10000;
} else {
/*
* if this is called in the middle of the aggregation, reset
@@ -879,7 +877,6 @@ static void damon_update_monitoring_result(struct damon_region *r,
*/
r->last_nr_accesses = damon_nr_accesses_for_new_attrs(
r->last_nr_accesses, old_attrs, new_attrs);
- r->nr_accesses_bp = r->last_nr_accesses * 10000;
r->nr_accesses = 0;
}
r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs);
@@ -3096,7 +3093,6 @@ static void damon_merge_two_regions(struct damon_target *t,
l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) /
(sz_l + sz_r);
- l->nr_accesses_bp = l->nr_accesses * 10000;
l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r);
l->ar.end = r->ar.end;
/* todo: do this for only installed probes */
@@ -3208,7 +3204,6 @@ static void damon_split_region_at(struct damon_target *t,
new->age = r->age;
new->last_nr_accesses = r->last_nr_accesses;
- new->nr_accesses_bp = r->nr_accesses_bp;
new->nr_accesses = r->nr_accesses;
/* todo: do this for only installed probes */
memcpy(new->probe_hits, r->probe_hits, sizeof(r->probe_hits));
@@ -3777,18 +3772,6 @@ static unsigned int damon_moving_sum(unsigned int mvsum, unsigned int nomvsum,
void damon_update_region_access_rate(struct damon_region *r, bool accessed,
struct damon_attrs *attrs)
{
- unsigned int len_window = 1;
-
- /*
- * sample_interval can be zero, but cannot be larger than
- * aggr_interval, owing to validation of damon_set_attrs().
- */
- if (attrs->sample_interval)
- len_window = damon_max_nr_accesses(attrs);
- r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp,
- r->last_nr_accesses * 10000, len_window,
- accessed ? 10000 : 0);
-
if (accessed)
r->nr_accesses++;
}
--
2.47.3