[RFC PATCH v2 08/28] mm/damon/paddr: support data attributes monitoring

[SeongJae Park <sj@kernel.org>]

Implement and register damon_operations->apply_probes() callback to
support data attributes monitoring.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/paddr.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index c4738cd5e221e..e60af2cbc1089 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -120,6 +120,67 @@ static unsigned int damon_pa_check_accesses(struct damon_ctx *ctx)
 	return max_nr_accesses;
 }
 
+static bool damon_pa_filter_match(struct damon_filter *filter,
+		struct folio *folio)
+{
+	bool matched = false;
+
+	switch (filter->type) {
+	case DAMON_FILTER_TYPE_ANON:
+		if (!folio) {
+			matched = false;
+			break;
+		}
+		matched = folio_test_anon(folio);
+		break;
+	default:
+		break;
+	}
+	return matched == filter->matching;
+}
+
+static bool damon_pa_filter_pass(phys_addr_t pa, struct damon_probe *p)
+{
+	struct damon_filter *f;
+	struct folio *folio;
+	bool pass = true;
+
+	folio = damon_get_folio(PHYS_PFN(pa));
+	damon_for_each_filter(f, p) {
+		if (damon_pa_filter_match(f, folio)) {
+			pass = f->allow;
+			break;
+		}
+		pass = !f->allow;
+	}
+	if (folio)
+		folio_put(folio);
+	return pass;
+}
+
+static void damon_pa_apply_probes(struct damon_ctx *ctx)
+{
+	struct damon_target *t;
+	struct damon_region *r;
+	struct damon_probe *p;
+
+	damon_for_each_target(t, ctx) {
+		damon_for_each_region(r, t) {
+			int i = 0;
+
+			damon_for_each_probe(p, ctx) {
+				phys_addr_t pa;
+
+				pa = damon_pa_phys_addr(r->sampling_addr,
+						ctx->addr_unit);
+				if (damon_pa_filter_pass(pa, p))
+					r->probe_hits[i]++;
+				i++;
+			}
+		}
+	}
+}
+
 /*
  * damos_pa_filter_out - Return true if the page should be filtered out.
  */
@@ -371,6 +432,7 @@ static int __init damon_pa_initcall(void)
 		.update = NULL,
 		.prepare_access_checks = damon_pa_prepare_access_checks,
 		.check_accesses = damon_pa_check_accesses,
+		.apply_probes = damon_pa_apply_probes,
 		.target_valid = NULL,
 		.apply_scheme = damon_pa_apply_scheme,
 		.get_scheme_score = damon_pa_scheme_score,
-- 
2.47.3