1 files changed, 103 insertions, 14 deletions
diff --git a/include/linux/damon.h b/include/linux/damon.h
index a67f2c4940e9..c9074d569596 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -193,11 +193,16 @@ struct damos_quota_goal {
  * size quota is set, DAMON tries to apply the action only up to &sz bytes
  * within &reset_interval.
  *
- * Internally, the time quota is transformed to a size quota using estimated
- * throughput of the scheme's action.  DAMON then compares it against &sz and
- * uses smaller one as the effective quota.
+ * To convince the different types of quotas and goals, DAMON internally
+ * converts those into one single size quota called "effective quota".  DAMON
+ * internally uses it as the only one real quota.  The conversion is made as
+ * follows.
  *
- * If @goals is not empt, DAMON calculates yet another size quota based on the
+ * The time quota is transformed to a size quota using estimated throughput of
+ * the scheme's action.  DAMON then compares it against &sz and uses smaller
+ * one as the effective quota.
+ *
+ * If @goals is not empty, DAMON calculates yet another size quota based on the
  * goals using its internal feedback loop algorithm, for every @reset_interval.
  * Then, if the new size quota is smaller than the effective quota, it uses the
  * new size quota as the effective quota.
@@ -286,13 +291,33 @@ struct damos_watermarks {
  * @sz_tried:	Total size of regions that the scheme is tried to be applied.
  * @nr_applied:	Total number of regions that the scheme is applied.
  * @sz_applied:	Total size of regions that the scheme is applied.
+ * @sz_ops_filter_passed:
+ *		Total bytes that passed ops layer-handled DAMOS filters.
  * @qt_exceeds: Total number of times the quota of the scheme has exceeded.
+ *
+ * "Tried an action to a region" in this context means the DAMOS core logic
+ * determined the region as eligible to apply the action.  The access pattern
+ * (&struct damos_access_pattern), quotas (&struct damos_quota), watermarks
+ * (&struct damos_watermarks) and filters (&struct damos_filter) that handled
+ * on core logic can affect this.  The core logic asks the operation set
+ * (&struct damon_operations) to apply the action to the region.
+ *
+ * "Applied an action to a region" in this context means the operation set
+ * (&struct damon_operations) successfully applied the action to the region, at
+ * least to a part of the region.  The filters (&struct damos_filter) that
+ * handled on operation set layer and type of the action and pages of the
+ * region can affect this.  For example, if a filter is set to exclude
+ * anonymous pages and the region has only anonymous pages, the region will be
+ * failed at applying the action.  If the action is &DAMOS_PAGEOUT and all
+ * pages of the region are already paged out, the region will be failed at
+ * applying the action.
  */
 struct damos_stat {
 	unsigned long nr_tried;
 	unsigned long sz_tried;
 	unsigned long nr_applied;
 	unsigned long sz_applied;
+	unsigned long sz_ops_filter_passed;
 	unsigned long qt_exceeds;
 };
 
@@ -327,8 +352,9 @@ enum damos_filter_type {
 
 /**
  * struct damos_filter - DAMOS action target memory filter.
- * @type:	Type of the page.
- * @matching:	If the matching page should filtered out or in.
+ * @type:	Type of the target memory.
+ * @matching:	Whether this is for @type-matching memory.
+ * @allow:	Whether to include or exclude the @matching memory.
  * @memcg_id:	Memcg id of the question if @type is DAMOS_FILTER_MEMCG.
  * @addr_range:	Address range if @type is DAMOS_FILTER_TYPE_ADDR.
  * @target_idx:	Index of the &struct damon_target of
@@ -337,13 +363,15 @@ enum damos_filter_type {
  * @list:	List head for siblings.
  *
  * Before applying the &damos->action to a memory region, DAMOS checks if each
- * page of the region matches to this and avoid applying the action if so.
- * Support of each filter type depends on the running &struct damon_operations
- * and the type.  Refer to &enum damos_filter_type for more detai.
+ * byte of the region matches to this given condition and avoid applying the
+ * action if so.  Support of each filter type depends on the running &struct
+ * damon_operations and the type.  Refer to &enum damos_filter_type for more
+ * details.
  */
 struct damos_filter {
 	enum damos_filter_type type;
 	bool matching;
+	bool allow;
 	union {
 		unsigned short memcg_id;
 		struct damon_addr_range addr_range;
@@ -352,6 +380,31 @@ struct damos_filter {
 	struct list_head list;
 };
 
+struct damon_ctx;
+struct damos;
+
+/**
+ * struct damos_walk_control - Control damos_walk().
+ *
+ * @walk_fn:	Function to be called back for each region.
+ * @data:	Data that will be passed to walk functions.
+ *
+ * Control damos_walk(), which requests specific kdamond to invoke the given
+ * function to each region that eligible to apply actions of the kdamond's
+ * schemes.  Refer to damos_walk() for more details.
+ */
+struct damos_walk_control {
+	void (*walk_fn)(void *data, struct damon_ctx *ctx,
+			struct damon_target *t, struct damon_region *r,
+			struct damos *s, unsigned long sz_filter_passed);
+	void *data;
+/* private: internal use only */
+	/* informs if the kdamond finished handling of the walk request */
+	struct completion completion;
+	/* informs if the walk is canceled. */
+	bool canceled;
+};
+
 /**
  * struct damos_access_pattern - Target access pattern of the given scheme.
  * @min_sz_region:	Minimum size of target regions.
@@ -415,6 +468,13 @@ struct damos {
 	 * @action
 	 */
 	unsigned long next_apply_sis;
+	/* informs if ongoing DAMOS walk for this scheme is finished */
+	bool walk_completed;
+	/*
+	 * If the current region in the filtering stage is allowed by core
+	 * layer-handled filters.  If true, operations layer allows it, too.
+	 */
+	bool core_filters_allowed;
 /* public: */
 	struct damos_quota quota;
 	struct damos_watermarks wmarks;
@@ -442,8 +502,6 @@ enum damon_ops_id {
 	NR_DAMON_OPS,
 };
 
-struct damon_ctx;
-
 /**
  * struct damon_operations - Monitoring operations for given use cases.
  *
@@ -487,7 +545,8 @@ struct damon_ctx;
  * @apply_scheme is called from @kdamond when a region for user provided
  * DAMON-based operation scheme is found.  It should apply the scheme's action
  * to the region and return bytes of the region that the action is successfully
- * applied.
+ * applied.  It should also report how many bytes of the region has passed
+ * filters (&struct damos_filter) that handled by itself.
  * @target_valid should check whether the target is still valid for the
  * monitoring.
  * @cleanup is called from @kdamond just before its termination.
@@ -504,7 +563,7 @@ struct damon_operations {
 			struct damos *scheme);
 	unsigned long (*apply_scheme)(struct damon_ctx *context,
 			struct damon_target *t, struct damon_region *r,
-			struct damos *scheme);
+			struct damos *scheme, unsigned long *sz_filter_passed);
 	bool (*target_valid)(struct damon_target *t);
 	void (*cleanup)(struct damon_ctx *context);
 };
@@ -552,6 +611,27 @@ struct damon_callback {
 	void (*before_terminate)(struct damon_ctx *context);
 };
 
+/*
+ * struct damon_call_control - Control damon_call().
+ *
+ * @fn:			Function to be called back.
+ * @data:		Data that will be passed to @fn.
+ * @return_code:	Return code from @fn invocation.
+ *
+ * Control damon_call(), which requests specific kdamond to invoke a given
+ * function.  Refer to damon_call() for more details.
+ */
+struct damon_call_control {
+	int (*fn)(void *data);
+	void *data;
+	int return_code;
+/* private: internal use only */
+	/* informs if the kdamond finished handling of the request */
+	struct completion completion;
+	/* informs if the kdamond canceled @fn infocation */
+	bool canceled;
+};
+
 /**
  * struct damon_attrs - Monitoring attributes for accuracy/overhead control.
  *
@@ -632,6 +712,12 @@ struct damon_ctx {
 	/* for scheme quotas prioritization */
 	unsigned long *regions_score_histogram;
 
+	struct damon_call_control *call_control;
+	struct mutex call_control_lock;
+
+	struct damos_walk_control *walk_control;
+	struct mutex walk_control_lock;
+
 /* public: */
 	struct task_struct *kdamond;
 	struct mutex kdamond_lock;
@@ -725,7 +811,7 @@ void damon_update_region_access_rate(struct damon_region *r, bool accessed,
 		struct damon_attrs *attrs);
 
 struct damos_filter *damos_new_filter(enum damos_filter_type type,
-		bool matching);
+		bool matching, bool allow);
 void damos_add_filter(struct damos *s, struct damos_filter *f);
 void damos_destroy_filter(struct damos_filter *f);
 
@@ -779,6 +865,9 @@ static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs
 int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive);
 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
 
+int damon_call(struct damon_ctx *ctx, struct damon_call_control *control);
+int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control);
+
 int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 				unsigned long *start, unsigned long *end);