4 files changed, 68 insertions, 12 deletions

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 36f6f1d21ff0..5b325749fc12 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1026,6 +1026,9 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
 	damon_for_each_scheme(s, c) {
 		struct damos_quota *quota = &s->quota;
 
+		if (c->passed_sample_intervals != s->next_apply_sis)
+			continue;
+
 		if (!s->wmarks.activated)
 			continue;
 
@@ -1176,10 +1179,6 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 		if (c->passed_sample_intervals != s->next_apply_sis)
 			continue;
 
-		s->next_apply_sis +=
-			(s->apply_interval_us ? s->apply_interval_us :
-			 c->attrs.aggr_interval) / sample_interval;
-
 		if (!s->wmarks.activated)
 			continue;
 
@@ -1195,6 +1194,14 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 		damon_for_each_region_safe(r, next_r, t)
 			damon_do_apply_schemes(c, t, r);
 	}
+
+	damon_for_each_scheme(s, c) {
+		if (c->passed_sample_intervals != s->next_apply_sis)
+			continue;
+		s->next_apply_sis +=
+			(s->apply_interval_us ? s->apply_interval_us :
+			 c->attrs.aggr_interval) / sample_interval;
+	}
 }
 
 /*
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index f2e5f9431892..3de2916a65c3 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -185,9 +185,21 @@ static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres)
 	return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO);
 }
 
+static void damon_lru_sort_copy_quota_status(struct damos_quota *dst,
+		struct damos_quota *src)
+{
+	dst->total_charged_sz = src->total_charged_sz;
+	dst->total_charged_ns = src->total_charged_ns;
+	dst->charged_sz = src->charged_sz;
+	dst->charged_from = src->charged_from;
+	dst->charge_target_from = src->charge_target_from;
+	dst->charge_addr_from = src->charge_addr_from;
+}
+
 static int damon_lru_sort_apply_parameters(void)
 {
-	struct damos *scheme;
+	struct damos *scheme, *hot_scheme, *cold_scheme;
+	struct damos *old_hot_scheme = NULL, *old_cold_scheme = NULL;
 	unsigned int hot_thres, cold_thres;
 	int err = 0;
 
@@ -195,18 +207,35 @@ static int damon_lru_sort_apply_parameters(void)
 	if (err)
 		return err;
 
+	damon_for_each_scheme(scheme, ctx) {
+		if (!old_hot_scheme) {
+			old_hot_scheme = scheme;
+			continue;
+		}
+		old_cold_scheme = scheme;
+	}
+
 	hot_thres = damon_max_nr_accesses(&damon_lru_sort_mon_attrs) *
 		hot_thres_access_freq / 1000;
-	scheme = damon_lru_sort_new_hot_scheme(hot_thres);
-	if (!scheme)
+	hot_scheme = damon_lru_sort_new_hot_scheme(hot_thres);
+	if (!hot_scheme)
 		return -ENOMEM;
-	damon_set_schemes(ctx, &scheme, 1);
+	if (old_hot_scheme)
+		damon_lru_sort_copy_quota_status(&hot_scheme->quota,
+				&old_hot_scheme->quota);
 
 	cold_thres = cold_min_age / damon_lru_sort_mon_attrs.aggr_interval;
-	scheme = damon_lru_sort_new_cold_scheme(cold_thres);
-	if (!scheme)
+	cold_scheme = damon_lru_sort_new_cold_scheme(cold_thres);
+	if (!cold_scheme) {
+		damon_destroy_scheme(hot_scheme);
 		return -ENOMEM;
-	damon_add_scheme(ctx, scheme);
+	}
+	if (old_cold_scheme)
+		damon_lru_sort_copy_quota_status(&cold_scheme->quota,
+				&old_cold_scheme->quota);
+
+	damon_set_schemes(ctx, &hot_scheme, 1);
+	damon_add_scheme(ctx, cold_scheme);
 
 	return damon_set_region_biggest_system_ram_default(target,
 					&monitor_region_start,
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index ab974e477d2f..66e190f0374a 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -150,9 +150,20 @@ static struct damos *damon_reclaim_new_scheme(void)
 			&damon_reclaim_wmarks);
 }
 
+static void damon_reclaim_copy_quota_status(struct damos_quota *dst,
+		struct damos_quota *src)
+{
+	dst->total_charged_sz = src->total_charged_sz;
+	dst->total_charged_ns = src->total_charged_ns;
+	dst->charged_sz = src->charged_sz;
+	dst->charged_from = src->charged_from;
+	dst->charge_target_from = src->charge_target_from;
+	dst->charge_addr_from = src->charge_addr_from;
+}
+
 static int damon_reclaim_apply_parameters(void)
 {
-	struct damos *scheme;
+	struct damos *scheme, *old_scheme;
 	struct damos_filter *filter;
 	int err = 0;
 
@@ -164,6 +175,11 @@ static int damon_reclaim_apply_parameters(void)
 	scheme = damon_reclaim_new_scheme();
 	if (!scheme)
 		return -ENOMEM;
+	if (!list_empty(&ctx->schemes)) {
+		damon_for_each_scheme(old_scheme, ctx)
+			damon_reclaim_copy_quota_status(&scheme->quota,
+					&old_scheme->quota);
+	}
 	if (skip_anon) {
 		filter = damos_new_filter(DAMOS_FILTER_TYPE_ANON, true);
 		if (!filter) {
diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index dd2fb5127009..ae0f0b314f3a 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -1905,6 +1905,10 @@ void damos_sysfs_set_quota_scores(struct damon_sysfs_schemes *sysfs_schemes,
 	damon_for_each_scheme(scheme, ctx) {
 		struct damon_sysfs_scheme *sysfs_scheme;
 
+		/* user could have removed the scheme sysfs dir */
+		if (i >= sysfs_schemes->nr)
+			break;
+
 		sysfs_scheme = sysfs_schemes->schemes_arr[i];
 		damos_sysfs_set_quota_score(sysfs_scheme->quotas->goals,
 				&scheme->quota);