741 static void free_heuristic_ws(struct list_head *ws)  in free_heuristic_ws()  argument
745 	workspace = list_entry(ws, struct heuristic_ws, list);  in free_heuristic_ws()
755 	struct heuristic_ws *ws;  in alloc_heuristic_ws()  local
757 	ws = kzalloc(sizeof(*ws), GFP_KERNEL);  in alloc_heuristic_ws()
758 	if (!ws)  in alloc_heuristic_ws()
761 	ws->sample = kvmalloc(MAX_SAMPLE_SIZE, GFP_KERNEL);  in alloc_heuristic_ws()
762 	if (!ws->sample)  in alloc_heuristic_ws()
765 	ws->bucket = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket), GFP_KERNEL);  in alloc_heuristic_ws()
766 	if (!ws->bucket)  in alloc_heuristic_ws()
769 	ws->bucket_b = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket_b), GFP_KERNEL);  in alloc_heuristic_ws()
770 	if (!ws->bucket_b)  in alloc_heuristic_ws()
773 	INIT_LIST_HEAD(&ws->list);  in alloc_heuristic_ws()
774 	return &ws->list;  in alloc_heuristic_ws()
776 	free_heuristic_ws(&ws->list);  in alloc_heuristic_ws()
988 static void free_workspace(int type, struct list_head *ws)  in free_workspace()  argument
990 	return __free_workspace(type, ws, false);  in free_workspace()
1246 static u32 shannon_entropy(struct heuristic_ws *ws)  in shannon_entropy()  argument
1253 	sz_base = ilog2_w(ws->sample_size);  in shannon_entropy()
1254 	for (i = 0; i < BUCKET_SIZE && ws->bucket[i].count > 0; i++) {  in shannon_entropy()
1255 		p = ws->bucket[i].count;  in shannon_entropy()
1260 	entropy_sum /= ws->sample_size;  in shannon_entropy()
1382 static int byte_core_set_size(struct heuristic_ws *ws)  in byte_core_set_size()  argument
1386 	const u32 core_set_threshold = ws->sample_size * 90 / 100;  in byte_core_set_size()
1387 	struct bucket_item *bucket = ws->bucket;  in byte_core_set_size()
1390 	radix_sort(ws->bucket, ws->bucket_b, BUCKET_SIZE);  in byte_core_set_size()
1420 static u32 byte_set_size(const struct heuristic_ws *ws)  in byte_set_size()  argument
1426 		if (ws->bucket[i].count > 0)  in byte_set_size()
1436 		if (ws->bucket[i].count > 0) {  in byte_set_size()
1446 static bool sample_repeated_patterns(struct heuristic_ws *ws)  in sample_repeated_patterns()  argument
1448 	const u32 half_of_sample = ws->sample_size / 2;  in sample_repeated_patterns()
1449 	const u8 *data = ws->sample;  in sample_repeated_patterns()
1455 				     struct heuristic_ws *ws)  in heuristic_collect_sample()  argument
1491 			memcpy(&ws->sample[curr_sample_pos], &in_data[i],  in heuristic_collect_sample()
1503 	ws->sample_size = curr_sample_pos;  in heuristic_collect_sample()
1524 	struct heuristic_ws *ws;  in btrfs_compress_heuristic()  local
1529 	ws = list_entry(ws_list, struct heuristic_ws, list);  in btrfs_compress_heuristic()
1531 	heuristic_collect_sample(inode, start, end, ws);  in btrfs_compress_heuristic()
1533 	if (sample_repeated_patterns(ws)) {  in btrfs_compress_heuristic()
1538 	memset(ws->bucket, 0, sizeof(*ws->bucket)*BUCKET_SIZE);  in btrfs_compress_heuristic()
1540 	for (i = 0; i < ws->sample_size; i++) {  in btrfs_compress_heuristic()
1541 		byte = ws->sample[i];  in btrfs_compress_heuristic()
1542 		ws->bucket[byte].count++;  in btrfs_compress_heuristic()
1545 	i = byte_set_size(ws);  in btrfs_compress_heuristic()
1551 	i = byte_core_set_size(ws);  in btrfs_compress_heuristic()
1562 	i = shannon_entropy(ws);  in btrfs_compress_heuristic()