Merge pull request #448 from robertbaldyga/perqueue-seq-cutoff

Per-queue multi-stream sequential cutoff

inc/ocf_core.h

@@ -112,6 +112,15 @@ uint32_t ocf_core_get_seq_cutoff_threshold(ocf_core_t core);
  */
 ocf_seq_cutoff_policy ocf_core_get_seq_cutoff_policy(ocf_core_t core);
 
+/**
+ * @brief Get sequential cutoff stream promotion req count of given core object
+ *
+ * @param[in] core Core object
+ *
+ * @retval Sequential cutoff stream promotion request count
+ */
+uint32_t ocf_core_get_seq_cutoff_promotion_count(ocf_core_t core);
+
 /**
  * @brief Get name of given core object
  *

inc/ocf_debug.h

@@ -12,7 +12,7 @@ struct ocf_dbg_seq_cutoff_status {
 		uint64_t bytes;
 		uint32_t rw : 1;
 		uint32_t active : 1;
-	} streams[OCF_SEQ_CUTOFF_MAX_STREAMS];
+	} streams[OCF_SEQ_CUTOFF_PERCORE_STREAMS];
 };
 
 void ocf_dbg_get_seq_cutoff_status(ocf_core_t core,

inc/ocf_def.h

@@ -175,9 +175,12 @@ typedef enum {
 		/*!< Current cache mode of given cache instance */
 } ocf_cache_mode_t;
 
-#define OCF_SEQ_CUTOFF_MAX_STREAMS 256
+#define OCF_SEQ_CUTOFF_PERCORE_STREAMS 128
+#define OCF_SEQ_CUTOFF_PERQUEUE_STREAMS 64
 #define OCF_SEQ_CUTOFF_MIN_THRESHOLD 1
 #define OCF_SEQ_CUTOFF_MAX_THRESHOLD 4194181
+#define OCF_SEQ_CUTOFF_MIN_PROMOTION_COUNT 1
+#define OCF_SEQ_CUTOFF_MAX_PROMOTION_COUNT 65535
 
 typedef enum {
 	ocf_seq_cutoff_policy_always = 0,

inc/ocf_mngt.h

@@ -42,6 +42,9 @@ struct ocf_mngt_core_config {
 	uint32_t seq_cutoff_threshold;
 		/*!< Sequential cutoff threshold (in bytes) */
 
+	uint32_t seq_cutoff_promotion_count;
+		/*!< Sequential cutoff promotion request count */
+
 	struct {
 		void *data;
 		size_t size;
@@ -61,6 +64,7 @@ static inline void ocf_mngt_core_config_set_default(
 {
 	cfg->try_add = false;
 	cfg->seq_cutoff_threshold = 1024;
+	cfg->seq_cutoff_promotion_count = 8;
 	cfg->user_metadata.data = NULL;
 	cfg->user_metadata.size = 0;
 }
@@ -1010,6 +1014,47 @@ int ocf_mngt_core_set_seq_cutoff_policy_all(ocf_cache_t cache,
 int ocf_mngt_core_get_seq_cutoff_policy(ocf_core_t core,
 		ocf_seq_cutoff_policy *policy);
 
+/**
+ * @brief Set core sequential cutoff promotion request count
+ *
+ * @attention This changes only runtime state. To make changes persistent
+ *            use function ocf_mngt_cache_save().
+ *
+ * @param[in] core Core handle
+ * @param[in] count promotion request count
+ *
+ * @retval 0 Sequential cutoff promotion requets count has been set successfully
+ * @retval Non-zero Error occured and request count hasn't been updated
+ */
+int ocf_mngt_core_set_seq_cutoff_promotion_count(ocf_core_t core,
+		uint32_t count);
+
+/**
+ * @brief Set sequential cutoff promotion request count for all cores in cache
+ *
+ * @attention This changes only runtime state. To make changes persistent
+ *            use function ocf_mngt_cache_save().
+ *
+ * @param[in] cache Cache handle
+ * @param[in] count promotion request count
+ *
+ * @retval 0 Sequential cutoff promotion request count has been set successfully
+ * @retval Non-zero Error occured and request count hasn't been updated
+ */
+int ocf_mngt_core_set_seq_cutoff_promotion_count_all(ocf_cache_t cache,
+		uint32_t count);
+/**
+ * @brief Get core sequential cutoff promotion threshold
+ *
+ * @param[in] core Core handle
+ * @param[out] count promotion request count
+ *
+ * @retval 0 Sequential cutoff promotion request count has been get successfully
+ * @retval Non-zero Error occured
+ */
+int ocf_mngt_core_get_seq_cutoff_promotion_count(ocf_core_t core,
+		uint32_t *count);
+
 /**
  * @brief Set cache fallback Pass Through error threshold
  *

src/mngt/ocf_mngt_core.c

@@ -451,6 +451,8 @@ static void ocf_mngt_cache_add_core_insert(ocf_pipeline_t pipeline,
 			ocf_seq_cutoff_policy_default);
 	env_atomic_set(&core->conf_meta->seq_cutoff_threshold,
 			cfg->seq_cutoff_threshold);
+	env_atomic_set(&core->conf_meta->seq_cutoff_promo_count,
+			cfg->seq_cutoff_promotion_count);
 
 	/* Add core sequence number for atomic metadata matching */
 	core_sequence_no = _ocf_mngt_get_core_seq_no(cache);
@@ -1016,3 +1018,62 @@ int ocf_mngt_core_get_seq_cutoff_policy(ocf_core_t core,
 
 	return 0;
 }
+
+static int _cache_mngt_set_core_seq_cutoff_promo_count(ocf_core_t core,
+		void *cntx)
+{
+	uint32_t count = *(uint32_t*) cntx;
+	uint32_t count_old = ocf_core_get_seq_cutoff_promotion_count(core);
+
+	if (count < OCF_SEQ_CUTOFF_MIN_PROMOTION_COUNT ||
+			count > OCF_SEQ_CUTOFF_MAX_PROMOTION_COUNT) {
+		ocf_core_log(core, log_info,
+				"Invalid sequential cutoff promotion count!\n");
+		return -OCF_ERR_INVAL;
+	}
+
+
+	if (count_old == count) {
+		ocf_core_log(core, log_info,
+				"Sequential cutoff promotion count %u "
+				"bytes is already set\n", count);
+		return 0;
+	}
+
+	env_atomic_set(&core->conf_meta->seq_cutoff_promo_count, count);
+
+	ocf_core_log(core, log_info, "Changing sequential cutoff promotion"
+			"count from %u to %u bytes successful\n",
+			count_old, count);
+
+	return 0;
+}
+
+int ocf_mngt_core_set_seq_cutoff_promotion_count(ocf_core_t core,
+		uint32_t count)
+{
+	OCF_CHECK_NULL(core);
+
+	return _cache_mngt_set_core_seq_cutoff_promo_count(core, &count);
+}
+
+int ocf_mngt_core_set_seq_cutoff_promotion_count_all(ocf_cache_t cache,
+		uint32_t count)
+{
+	OCF_CHECK_NULL(cache);
+
+	return ocf_core_visit(cache,
+			_cache_mngt_set_core_seq_cutoff_promo_count,
+			&count, true);
+}
+
+int ocf_mngt_core_get_seq_cutoff_promotion_count(ocf_core_t core,
+		uint32_t *count)
+{
+	OCF_CHECK_NULL(core);
+	OCF_CHECK_NULL(count);
+
+	*count = ocf_core_get_seq_cutoff_promotion_count(core);
+
+	return 0;
+}

src/ocf_cache.c

@@ -11,6 +11,7 @@
 #include "utils/utils_part.h"
 #include "ocf_priv.h"
 #include "ocf_cache_priv.h"
+#include "ocf_queue_priv.h"
 #include "utils/utils_stats.h"
 
 ocf_volume_t ocf_cache_get_volume(ocf_cache_t cache)

src/ocf_core.c

@@ -114,6 +114,11 @@ ocf_seq_cutoff_policy ocf_core_get_seq_cutoff_policy(ocf_core_t core)
 	return env_atomic_read(&core->conf_meta->seq_cutoff_policy);
 }
 
+uint32_t ocf_core_get_seq_cutoff_promotion_count(ocf_core_t core)
+{
+	return env_atomic_read(&core->conf_meta->seq_cutoff_promo_count);
+}
+
 int ocf_core_visit(ocf_cache_t cache, ocf_core_visitor_t visitor, void *cntx,
 		bool only_opened)
 {

src/ocf_core_priv.h

@@ -44,6 +44,9 @@ struct ocf_core_meta_config {
 	/* Sequential cutoff policy */
 	env_atomic seq_cutoff_policy;
 
+	/* Sequential cutoff stream promotion request count */
+	env_atomic seq_cutoff_promo_count;
+
 	/* core object size in bytes */
 	uint64_t length;
 

src/ocf_queue.c

@@ -44,6 +44,13 @@ int ocf_queue_create(ocf_cache_t cache, ocf_queue_t *queue,
 	tmp_queue->cache = cache;
 	tmp_queue->ops = ops;
 
+	result = ocf_queue_seq_cutoff_init(tmp_queue);
+	if (result) {
+		ocf_mngt_cache_put(cache);
+		env_free(tmp_queue);
+		return result;
+	}
+
 	list_add(&tmp_queue->list, &cache->io_queues);
 
 	*queue = tmp_queue;
@@ -65,6 +72,7 @@ void ocf_queue_put(ocf_queue_t queue)
 	if (env_atomic_dec_return(&queue->ref_count) == 0) {
 		list_del(&queue->list);
 		queue->ops->stop(queue);
+		ocf_queue_seq_cutoff_deinit(queue);
 		ocf_mngt_cache_put(queue->cache);
 		env_spinlock_destroy(&queue->io_list_lock);
 		env_free(queue);

src/ocf_queue_priv.h

@@ -34,6 +34,8 @@ struct ocf_queue {
 
 	const struct ocf_queue_ops *ops;
 
+	struct ocf_seq_cutoff *seq_cutoff;
+
 	void *priv;
 };
 

src/ocf_request.h

@@ -187,6 +187,9 @@ struct ocf_request {
 	uint8_t master_io_req_type : 2;
 	/*!< Core device request context type */
 
+	uint8_t seq_cutoff_core : 1;
+	/*!< Sequential cut off stream promoted to core level */
+
 	uint8_t seq_cutoff : 1;
 	/*!< Sequential cut off set for this request */
 

src/ocf_seq_cutoff.c

@@ -5,6 +5,8 @@
 
 #include "ocf_seq_cutoff.h"
 #include "ocf_cache_priv.h"
+#include "ocf_core_priv.h"
+#include "ocf_queue_priv.h"
 #include "ocf_priv.h"
 #include "ocf/ocf_debug.h"
 #include "utils/utils_cache_line.h"
@@ -51,50 +53,86 @@ static struct ocf_rb_node *ocf_seq_cutoff_stream_list_find(
 	struct ocf_rb_node *node;
 
 	node = list_entry(node_list, struct ocf_rb_node, list);
-	max_stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+	stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+	if (stream->valid)
+		max_stream = stream;
 	list_for_each_entry(node, node_list, list) {
 		stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+		if (!stream->valid)
+			continue;
+		if (!max_stream)
+			max_stream = stream;
 		if (stream->bytes > max_stream->bytes)
 			max_stream = stream;
 	}
 
-	return &max_stream->node;
+	return max_stream ? &max_stream->node : NULL;
 }
 
-int ocf_core_seq_cutoff_init(ocf_core_t core)
+static void ocf_seq_cutoff_base_init(struct ocf_seq_cutoff *base, int nstreams)
 {
 	struct ocf_seq_cutoff_stream *stream;
 	int i;
 
-	ocf_core_log(core, log_info, "Seqential cutoff init\n");
+	env_rwlock_init(&base->lock);
-
+	ocf_rb_tree_init(&base->tree, ocf_seq_cutoff_stream_cmp,
-	core->seq_cutoff = env_vmalloc(sizeof(*core->seq_cutoff));
-	if (!core->seq_cutoff)
-		return -OCF_ERR_NO_MEM;
-
-	env_rwlock_init(&core->seq_cutoff->lock);
-	ocf_rb_tree_init(&core->seq_cutoff->tree, ocf_seq_cutoff_stream_cmp,
 			ocf_seq_cutoff_stream_list_find);
-	INIT_LIST_HEAD(&core->seq_cutoff->lru);
+	INIT_LIST_HEAD(&base->lru);
 
-	for (i = 0; i < OCF_SEQ_CUTOFF_MAX_STREAMS; i++) {
+	for (i = 0; i < nstreams; i++) {
-		stream = &core->seq_cutoff->streams[i];
+		stream = &base->streams[i];
 		stream->last = 4096 * i;
 		stream->bytes = 0;
 		stream->rw = 0;
-		ocf_rb_tree_insert(&core->seq_cutoff->tree, &stream->node);
+		stream->valid = false;
-		list_add_tail(&stream->list, &core->seq_cutoff->lru);
+		ocf_rb_tree_insert(&base->tree, &stream->node);
+		list_add_tail(&stream->list, &base->lru);
 	}
+}
+
+void ocf_seq_cutoff_base_deinit(struct ocf_seq_cutoff *base)
+{
+	env_rwlock_destroy(&base->lock);
+}
+
+int ocf_core_seq_cutoff_init(ocf_core_t core)
+{
+	ocf_core_log(core, log_info, "Seqential cutoff init\n");
+
+	core->seq_cutoff = env_vmalloc(sizeof(struct ocf_seq_cutoff_percore));
+	if (!core->seq_cutoff)
+		return -OCF_ERR_NO_MEM;
+
+	ocf_seq_cutoff_base_init(core->seq_cutoff,
+			OCF_SEQ_CUTOFF_PERCORE_STREAMS);
 
 	return 0;
 }
 
 void ocf_core_seq_cutoff_deinit(ocf_core_t core)
 {
-	env_rwlock_destroy(&core->seq_cutoff->lock);
+	ocf_seq_cutoff_base_deinit(core->seq_cutoff);
 	env_vfree(core->seq_cutoff);
 }
 
+int ocf_queue_seq_cutoff_init(ocf_queue_t queue)
+{
+	queue->seq_cutoff = env_vmalloc(sizeof(struct ocf_seq_cutoff_perqueue));
+	if (!queue->seq_cutoff)
+		return -OCF_ERR_NO_MEM;
+
+	ocf_seq_cutoff_base_init(queue->seq_cutoff,
+			OCF_SEQ_CUTOFF_PERQUEUE_STREAMS);
+
+	return 0;
+}
+
+void ocf_queue_seq_cutoff_deinit(ocf_queue_t queue)
+{
+	ocf_seq_cutoff_base_deinit(queue->seq_cutoff);
+	env_vfree(queue->seq_cutoff);
+}
+
 void ocf_dbg_get_seq_cutoff_status(ocf_core_t core,
 		struct ocf_dbg_seq_cutoff_status *status)
 {
@@ -118,17 +156,38 @@ void ocf_dbg_get_seq_cutoff_status(ocf_core_t core,
 	env_rwlock_read_unlock(&core->seq_cutoff->lock);
 }
 
+static bool ocf_core_seq_cutoff_base_check(struct ocf_seq_cutoff *seq_cutoff,
+		uint64_t addr, uint32_t len, int rw, uint32_t threshold,
+		struct ocf_seq_cutoff_stream **out_stream)
+{
+	struct ocf_seq_cutoff_stream item = {
+		.last = addr, .rw = rw
+	};
+	struct ocf_seq_cutoff_stream *stream;
+	struct ocf_rb_node *node;
+	bool result = false;
+
+	node = ocf_rb_tree_find(&seq_cutoff->tree, &item.node);
+	if (node) {
+		stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+		if (stream->bytes + len >= threshold)
+			result = true;
+
+		if (out_stream)
+			*out_stream = stream;
+	}
+
+	return result;
+}
+
 bool ocf_core_seq_cutoff_check(ocf_core_t core, struct ocf_request *req)
 {
 	ocf_seq_cutoff_policy policy = ocf_core_get_seq_cutoff_policy(core);
 	uint32_t threshold = ocf_core_get_seq_cutoff_threshold(core);
 	ocf_cache_t cache = ocf_core_get_cache(core);
-	struct ocf_seq_cutoff_stream item = {
+	struct ocf_seq_cutoff_stream *queue_stream = NULL;
-		.last = req->byte_position, .rw = req->rw
+	struct ocf_seq_cutoff_stream *core_stream = NULL;
-	};
+	bool result;
-	struct ocf_seq_cutoff_stream *stream;
-	struct ocf_rb_node *node;
-	bool result = false;
 
 	switch (policy) {
 		case ocf_seq_cutoff_policy_always:
@@ -145,55 +204,134 @@ bool ocf_core_seq_cutoff_check(ocf_core_t core, struct ocf_request *req)
 			return false;
 	}
 
+	result = ocf_core_seq_cutoff_base_check(req->io_queue->seq_cutoff,
+			req->byte_position, req->byte_length, req->rw,
+			threshold, &queue_stream);
+	if (queue_stream)
+		return result;
+
 	env_rwlock_read_lock(&core->seq_cutoff->lock);
-	node = ocf_rb_tree_find(&core->seq_cutoff->tree, &item.node);
+	result = ocf_core_seq_cutoff_base_check(core->seq_cutoff,
-	if (node) {
+			req->byte_position, req->byte_length, req->rw,
-		stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+			threshold, &core_stream);
-		if (stream->bytes + req->byte_length >= threshold)
-			result = true;
-	}
 	env_rwlock_read_unlock(&core->seq_cutoff->lock);
 
+	if (core_stream)
+		req->seq_cutoff_core = true;
+
 	return result;
 }
 
-void ocf_core_seq_cutoff_update(ocf_core_t core, struct ocf_request *req)
+static struct ocf_seq_cutoff_stream *ocf_core_seq_cutoff_base_update(
+		struct ocf_seq_cutoff *seq_cutoff,
+		uint64_t addr, uint32_t len, int rw, bool insert)
 {
-	ocf_seq_cutoff_policy policy = ocf_core_get_seq_cutoff_policy(core);
 	struct ocf_seq_cutoff_stream item = {
-		.last = req->byte_position, .rw = req->rw
+		.last = addr, .rw = rw
 	};
 	struct ocf_seq_cutoff_stream *stream;
 	struct ocf_rb_node *node;
 	bool can_update;
 
+	node = ocf_rb_tree_find(&seq_cutoff->tree, &item.node);
+	if (node) {
+		stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+		item.last = addr + len;
+		can_update = ocf_rb_tree_can_update(&seq_cutoff->tree,
+				node, &item.node);
+		stream->last = addr + len;
+		stream->bytes += len;
+		stream->req_count++;
+		if (!can_update) {
+			ocf_rb_tree_remove(&seq_cutoff->tree, node);
+			ocf_rb_tree_insert(&seq_cutoff->tree, node);
+		}
+		list_move_tail(&stream->list, &seq_cutoff->lru);
+
+		return stream;
+	}
+
+	if (insert) {
+		stream = list_first_entry(&seq_cutoff->lru,
+				struct ocf_seq_cutoff_stream, list);
+		ocf_rb_tree_remove(&seq_cutoff->tree, &stream->node);
+		stream->rw = rw;
+		stream->last = addr + len;
+		stream->bytes = len;
+		stream->req_count = 1;
+		stream->valid = true;
+		ocf_rb_tree_insert(&seq_cutoff->tree, &stream->node);
+		list_move_tail(&stream->list, &seq_cutoff->lru);
+
+		return stream;
+	}
+
+	return NULL;
+}
+
+static void ocf_core_seq_cutoff_base_promote(
+		struct ocf_seq_cutoff *dst_seq_cutoff,
+		struct ocf_seq_cutoff *src_seq_cutoff,
+		struct ocf_seq_cutoff_stream *src_stream)
+{
+	struct ocf_seq_cutoff_stream *dst_stream;
+
+	dst_stream = list_first_entry(&dst_seq_cutoff->lru,
+			struct ocf_seq_cutoff_stream, list);
+	ocf_rb_tree_remove(&dst_seq_cutoff->tree, &dst_stream->node);
+	dst_stream->rw = src_stream->rw;
+	dst_stream->last = src_stream->last;
+	dst_stream->bytes = src_stream->bytes;
+	dst_stream->req_count = src_stream->req_count;
+	dst_stream->valid = true;
+	ocf_rb_tree_insert(&dst_seq_cutoff->tree, &dst_stream->node);
+	list_move_tail(&dst_stream->list, &dst_seq_cutoff->lru);
+	src_stream->valid = false;
+	list_move(&src_stream->list, &src_seq_cutoff->lru);
+}
+
+void ocf_core_seq_cutoff_update(ocf_core_t core, struct ocf_request *req)
+{
+	ocf_seq_cutoff_policy policy = ocf_core_get_seq_cutoff_policy(core);
+	uint32_t threshold = ocf_core_get_seq_cutoff_threshold(core);
+	uint32_t promotion_count =
+			ocf_core_get_seq_cutoff_promotion_count(core);
+	struct ocf_seq_cutoff_stream *stream;
+	bool promote = false;
+
 	if (policy == ocf_seq_cutoff_policy_never)
 		return;
 
-	/* Update last accessed position and bytes counter */
+	if (req->byte_length >= threshold)
+		promote = true;
+
+	if (promotion_count == 0)
+		promote = true;
+
+	if (req->seq_cutoff_core || promote) {
 		env_rwlock_write_lock(&core->seq_cutoff->lock);
-	node = ocf_rb_tree_find(&core->seq_cutoff->tree, &item.node);
+		stream = ocf_core_seq_cutoff_base_update(core->seq_cutoff,
-	if (node) {
+				req->byte_position, req->byte_length, req->rw,
-		stream = container_of(node, struct ocf_seq_cutoff_stream, node);
+				promote);
-		item.last = req->byte_position + req->byte_length;
+		env_rwlock_write_unlock(&core->seq_cutoff->lock);
-		can_update = ocf_rb_tree_can_update(&core->seq_cutoff->tree,
+
-				node, &item.node);
+		if (stream)
-		stream->last = req->byte_position + req->byte_length;
+			return;
-		stream->bytes += req->byte_length;
-		if (!can_update) {
-			ocf_rb_tree_remove(&core->seq_cutoff->tree, node);
-			ocf_rb_tree_insert(&core->seq_cutoff->tree, node);
-		}
-		list_move_tail(&stream->list, &core->seq_cutoff->lru);
-	} else {
-		stream = list_first_entry(&core->seq_cutoff->lru,
-				struct ocf_seq_cutoff_stream, list);
-		ocf_rb_tree_remove(&core->seq_cutoff->tree, &stream->node);
-		stream->rw = req->rw;
-		stream->last = req->byte_position + req->byte_length;
-		stream->bytes = req->byte_length;
-		ocf_rb_tree_insert(&core->seq_cutoff->tree, &stream->node);
-		list_move_tail(&stream->list, &core->seq_cutoff->lru);
 	}
+
+	stream = ocf_core_seq_cutoff_base_update(req->io_queue->seq_cutoff,
+			req->byte_position, req->byte_length, req->rw, true);
+
+	if (stream->bytes >= threshold)
+		promote = true;
+
+	if (stream->req_count >= promotion_count)
+		promote = true;
+
+	if (promote) {
+		env_rwlock_write_lock(&core->seq_cutoff->lock);
+		ocf_core_seq_cutoff_base_promote(core->seq_cutoff,
+				req->io_queue->seq_cutoff, stream);
 		env_rwlock_write_unlock(&core->seq_cutoff->lock);
 	}
+}

src/ocf_seq_cutoff.h

@@ -14,6 +14,8 @@ struct ocf_seq_cutoff_stream {
 	uint64_t last;
 	uint64_t bytes;
 	uint32_t rw : 1;
+	uint32_t valid : 1;
+	uint32_t req_count : 16;
 	struct ocf_rb_node node;
 	struct list_head list;
 };
@@ -21,15 +23,29 @@ struct ocf_seq_cutoff_stream {
 struct ocf_seq_cutoff {
 	ocf_core_t core;
 	env_rwlock lock;
-	struct ocf_seq_cutoff_stream streams[OCF_SEQ_CUTOFF_MAX_STREAMS];
 	struct ocf_rb_tree tree;
 	struct list_head lru;
+	struct ocf_seq_cutoff_stream streams[];
+};
+
+struct ocf_seq_cutoff_percore {
+	struct ocf_seq_cutoff base;
+	struct ocf_seq_cutoff_stream streams[OCF_SEQ_CUTOFF_PERCORE_STREAMS];
+};
+
+struct ocf_seq_cutoff_perqueue {
+	struct ocf_seq_cutoff base;
+	struct ocf_seq_cutoff_stream streams[OCF_SEQ_CUTOFF_PERQUEUE_STREAMS];
 };
 
 int ocf_core_seq_cutoff_init(ocf_core_t core);
 
 void ocf_core_seq_cutoff_deinit(ocf_core_t core);
 
+int ocf_queue_seq_cutoff_init(ocf_queue_t queue);
+
+void ocf_queue_seq_cutoff_deinit(ocf_queue_t queue);
+
 bool ocf_core_seq_cutoff_check(ocf_core_t core, struct ocf_request *req);
 
 void ocf_core_seq_cutoff_update(ocf_core_t core, struct ocf_request *req);

tests/functional/pyocf/types/core.py

@@ -45,6 +45,7 @@ class CoreConfig(Structure):
         ("_volume_type", c_uint8),
         ("_try_add", c_bool),
         ("_seq_cutoff_threshold", c_uint32),
+        ("_seq_cutoff_promotion_count", c_uint32),
         ("_user_metadata", UserMetadata),
     ]
 
@@ -52,6 +53,7 @@ class CoreConfig(Structure):
 class Core:
     DEFAULT_ID = 4096
     DEFAULT_SEQ_CUTOFF_THRESHOLD = 1024 * 1024
+    DEFAULT_SEQ_CUTOFF_PROMOTION_COUNT = 8
 
     def __init__(
         self,
@@ -59,6 +61,7 @@ class Core:
         try_add: bool,
         name: str = "core",
         seq_cutoff_threshold: int = DEFAULT_SEQ_CUTOFF_THRESHOLD,
+        seq_cutoff_promotion_count: int = DEFAULT_SEQ_CUTOFF_PROMOTION_COUNT,
     ):
         self.cache = None
         self.device = device
@@ -76,6 +79,7 @@ class Core:
             _volume_type=self.device.type_id,
             _try_add=try_add,
             _seq_cutoff_threshold=seq_cutoff_threshold,
+            _seq_cutoff_promotion_count=seq_cutoff_promotion_count,
             _user_metadata=UserMetadata(_data=None, _size=0),
         )
 

tests/functional/tests/engine/test_seq_cutoff.py

@@ -71,7 +71,7 @@ def test_seq_cutoff_max_streams(pyocf_ctx):
         handled by cache. It should no longer be tracked by OCF, because of request in step 3. which
         overflowed the OCF handling structure)
     """
-    MAX_STREAMS = 256
+    MAX_STREAMS = 128
     TEST_STREAMS = MAX_STREAMS + 1  # Number of streams used by test - one more than OCF can track
     core_size = Size.from_MiB(200)
     threshold = Size.from_KiB(4)
@@ -91,7 +91,7 @@ def test_seq_cutoff_max_streams(pyocf_ctx):
     streams.remove(non_active_stream)
 
     cache = Cache.start_on_device(Volume(Size.from_MiB(200)), cache_mode=CacheMode.WT)
-    core = Core.using_device(Volume(core_size))
+    core = Core.using_device(Volume(core_size), seq_cutoff_promotion_count=1)
 
     cache.add_core(core)