[RFC PATCH v2.1 23/28] mm/damon/paddr: support DAMON_FILTER_TYPE_MEMCG

[SeongJae Park <sj@kernel.org>]

Implement the support of DAMON_FILTER_TYPE_MEMCG on the DAMON operation
set implementation for the physical address space.

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

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index e60af2cbc1089..f093485fd16a6 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -124,6 +124,7 @@ static bool damon_pa_filter_match(struct damon_filter *filter,
 		struct folio *folio)
 {
 	bool matched = false;
+	struct mem_cgroup *memcg;
 
 	switch (filter->type) {
 	case DAMON_FILTER_TYPE_ANON:
@@ -133,6 +134,19 @@ static bool damon_pa_filter_match(struct damon_filter *filter,
 		}
 		matched = folio_test_anon(folio);
 		break;
+	case DAMON_FILTER_TYPE_MEMCG:
+		if (!folio) {
+			matched = false;
+			break;
+		}
+		rcu_read_lock();
+		memcg = folio_memcg_check(folio);
+		if (!memcg)
+			matched = false;
+		else
+			matched = filter->memcg_id == mem_cgroup_id(memcg);
+		rcu_read_unlock();
+		break;
 	default:
 		break;
 	}
-- 
2.47.3