[RFC PATCH v2 05/10] mm/damon/sysfs-schemes: support DAMOS_QUOTA_NODE_MEMCG_USED_BP

[SeongJae Park <sj@kernel.org>]

Add support of DAMOS_QUOTA_NODE_MEMCG_USED_BP.  For this, extend quota
goal metric inputs for the new metric, and update DAMOS core layer
request construction logic to set the target cgroup, which is specified
by the user, via the 'path' file.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs-schemes.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 2c440a2b80e6..c679e62fd4b9 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -1030,6 +1030,10 @@ struct damos_sysfs_qgoal_metric_name damos_sysfs_qgoal_metric_names[] = {
 		.metric = DAMOS_QUOTA_NODE_MEM_FREE_BP,
 		.name = "node_mem_free_bp",
 	},
+	{
+		.metric = DAMOS_QUOTA_NODE_MEMCG_USED_BP,
+		.name = "node_memcg_used_bp",
+	},
 };
 
 static ssize_t target_metric_show(struct kobject *kobj,
@@ -2526,7 +2530,7 @@ static int damos_sysfs_add_quota_score(
 		struct damos_quota *quota)
 {
 	struct damos_quota_goal *goal;
-	int i;
+	int i, err;
 
 	for (i = 0; i < sysfs_goals->nr; i++) {
 		struct damos_sysfs_quota_goal *sysfs_goal =
@@ -2547,6 +2551,15 @@ static int damos_sysfs_add_quota_score(
 		case DAMOS_QUOTA_NODE_MEM_FREE_BP:
 			goal->nid = sysfs_goal->nid;
 			break;
+		case DAMOS_QUOTA_NODE_MEMCG_USED_BP:
+			err = damon_sysfs_memcg_path_to_id(
+					sysfs_goal->path, &goal->memcg_id);
+			if (err) {
+				damos_destroy_quota_goal(goal);
+				return err;
+			}
+			goal->nid = sysfs_goal->nid;
+			break;
 		default:
 			break;
 		}
-- 
2.39.5