[RFC PATCH 02/11] mm/damon: add a new DAMOS quota goal metric for cgroup on node memory usage

[SeongJae Park <sj@kernel.org>]

Define a new DAMOS quota auto-tuning target metrics for per-cgroup
per-node memory usage.  Also extend damos_quota_goal struct to have a
field for specifying the cgroup of the interest.

Note that this commit is only for DAMON kernel API extension.  Real
behavior of the new metric will be implemented by a following commit.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/damon.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 39b835dd3c4d..43aef959d357 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -175,6 +175,7 @@ enum damos_action {
  * @DAMOS_QUOTA_SOME_MEM_PSI_US:	System level some memory PSI in us.
  * @DAMOS_QUOTA_NODE_MEM_USED_BP:	MemUsed ratio of a node.
  * @DAMOS_QUOTA_NODE_MEM_FREE_BP:	MemFree ratio of a node.
+ * @DAMOS_QUOTA_NODE_MEMCG_USED_BP:	MemUsed ratio of a node for a cgroup.
  * @DAMOS_QUOTA_ACTIVE_MEM_BP:		Active to inactive memory ratio.
  * @NR_DAMOS_QUOTA_GOAL_METRICS:	Number of DAMOS quota goal metrics.
  *
@@ -185,6 +186,7 @@ enum damos_quota_goal_metric {
 	DAMOS_QUOTA_SOME_MEM_PSI_US,
 	DAMOS_QUOTA_NODE_MEM_USED_BP,
 	DAMOS_QUOTA_NODE_MEM_FREE_BP,
+	DAMOS_QUOTA_NODE_MEMCG_USED_BP,
 	DAMOS_QUOTA_ACTIVE_MEM_BP,
 	NR_DAMOS_QUOTA_GOAL_METRICS,
 };
@@ -196,6 +198,7 @@ enum damos_quota_goal_metric {
  * @current_value:	Current value of @metric.
  * @last_psi_total:	Last measured total PSI
  * @nid:		Node id.
+ * @memcg:		Memcg id.
  * @list:		List head for siblings.
  *
  * Data structure for getting the current score of the quota tuning goal.  The
@@ -209,6 +212,9 @@ enum damos_quota_goal_metric {
  *
  * If @metric is DAMOS_QUOTA_NODE_MEM_{USED,FREE}_BP, @nid represents the node
  * id of the target node to account the used/free memory.
+ *
+ * If @metric is DAMOS_QUOTA_NODE_MEMCG_USED_BP, @nid and @memcg_id represents
+ * the node id and the cgroup to account the used memory for.
  */
 struct damos_quota_goal {
 	enum damos_quota_goal_metric metric;
@@ -217,7 +223,10 @@ struct damos_quota_goal {
 	/* metric-dependent fields */
 	union {
 		u64 last_psi_total;
-		int nid;
+		struct {
+			int nid;
+			unsigned short memcg_id;
+		};
 	};
 	struct list_head list;
 };
-- 
2.39.5