mm/damon/sysfs-schemes: set damos->migrate_dests

Pass user-specified multiple DAMOS action destinations and their weights
to DAMON core API, so that user requests can really work.

Link: https://lkml.kernel.org/r/20250709005952.17776-5-bijan311@gmail.com
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Bijan Tabatabai <bijantabatab@micron.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ravi Shankar Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index b9434cdaacdc..74056bcd6a2c 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -2576,6 +2576,29 @@ void damos_sysfs_update_effective_quotas(
 	}
 }
 
+static int damos_sysfs_add_migrate_dest(struct damos *scheme,
+		struct damos_sysfs_dests *sysfs_dests)
+{
+	struct damos_migrate_dests *dests = &scheme->migrate_dests;
+	int i;
+
+	dests->node_id_arr = kmalloc_array(sysfs_dests->nr,
+			sizeof(*dests->node_id_arr), GFP_KERNEL);
+	if (!dests->node_id_arr)
+		return -ENOMEM;
+	dests->weight_arr = kmalloc_array(sysfs_dests->nr,
+			sizeof(*dests->weight_arr), GFP_KERNEL);
+	if (!dests->weight_arr)
+		/* ->node_id_arr will be freed by scheme destruction */
+		return -ENOMEM;
+	for (i = 0; i < sysfs_dests->nr; i++) {
+		dests->node_id_arr[i] = sysfs_dests->dests_arr[i]->id;
+		dests->weight_arr[i] = sysfs_dests->dests_arr[i]->weight;
+	}
+	dests->nr_dests = sysfs_dests->nr;
+	return 0;
+}
+
 static struct damos *damon_sysfs_mk_scheme(
 		struct damon_sysfs_scheme *sysfs_scheme)
 {
@@ -2638,6 +2661,11 @@ static struct damos *damon_sysfs_mk_scheme(
 		damon_destroy_scheme(scheme);
 		return NULL;
 	}
+	err = damos_sysfs_add_migrate_dest(scheme, sysfs_scheme->dests);
+	if (err) {
+		damon_destroy_scheme(scheme);
+		return NULL;
+	}
 	return scheme;
 }