xref: /dpdk/lib/sched/rte_sched.h (revision 719834a6849e1daf4a70ff7742bbcc3ae7e25607)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef __INCLUDE_RTE_SCHED_H__
6 #define __INCLUDE_RTE_SCHED_H__
7 
8 /**
9  * @file
10  * RTE Hierarchical Scheduler
11  *
12  * The hierarchical scheduler prioritizes the transmission of packets
13  * from different users and traffic classes according to the Service
14  * Level Agreements (SLAs) defined for the current network node.
15  *
16  * The scheduler supports thousands of packet queues grouped under a
17  * 5-level hierarchy:
18  *     1. Port:
19  *           - Typical usage: output Ethernet port;
20  *           - Multiple ports are scheduled in round robin order with
21  *	    equal priority;
22  *     2. Subport:
23  *           - Typical usage: group of users;
24  *           - Traffic shaping using the token bucket algorithm
25  *	    (one bucket per subport);
26  *           - Upper limit enforced per traffic class at subport level;
27  *           - Lower priority traffic classes able to reuse subport
28  *	    bandwidth currently unused by higher priority traffic
29  *	    classes of the same subport;
30  *           - When any subport traffic class is oversubscribed
31  *	    (configuration time event), the usage of subport member
32  *	    pipes with high demand for that traffic class pipes is
33  *	    truncated to a dynamically adjusted value with no
34  *             impact to low demand pipes;
35  *     3. Pipe:
36  *           - Typical usage: individual user/subscriber;
37  *           - Traffic shaping using the token bucket algorithm
38  *	    (one bucket per pipe);
39  *     4. Traffic class:
40  *           - Traffic classes of the same pipe handled in strict
41  *	    priority order;
42  *           - Upper limit enforced per traffic class at the pipe level;
43  *           - Lower priority traffic classes able to reuse pipe
44  *	    bandwidth currently unused by higher priority traffic
45  *	    classes of the same pipe;
46  *     5. Queue:
47  *           - Typical usage: queue hosting packets from one or
48  *	    multiple connections of same traffic class belonging to
49  *	    the same user;
50  *           - Weighted Round Robin (WRR) is used to service the
51  *	    queues within same pipe lowest priority traffic class (best-effort).
52  */
53 
54 #include <rte_mbuf.h>
55 #include <rte_meter.h>
56 
57 /** Congestion Management */
58 #include "rte_red.h"
59 #include "rte_pie.h"
60 
61 #ifdef __cplusplus
62 extern "C" {
63 #endif
64 
65 /** Maximum number of queues per pipe.
66  * Note that the multiple queues (power of 2) can only be assigned to
67  * lowest priority (best-effort) traffic class. Other higher priority traffic
68  * classes can only have one queue.
69  * Can not change.
70  *
71  * @see struct rte_sched_port_params
72  */
73 #define RTE_SCHED_QUEUES_PER_PIPE    16
74 
75 /** Number of WRR queues for best-effort traffic class per pipe.
76  *
77  * @see struct rte_sched_pipe_params
78  */
79 #define RTE_SCHED_BE_QUEUES_PER_PIPE    4
80 
81 /** Number of traffic classes per pipe (as well as subport).
82  * @see struct rte_sched_subport_params
83  * @see struct rte_sched_pipe_params
84  */
85 #define RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE    \
86 (RTE_SCHED_QUEUES_PER_PIPE - RTE_SCHED_BE_QUEUES_PER_PIPE + 1)
87 
88 /** Best-effort traffic class ID
89  * Can not change.
90  */
91 #define RTE_SCHED_TRAFFIC_CLASS_BE    (RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE - 1)
92 
93 /*
94  * Ethernet framing overhead. Overhead fields per Ethernet frame:
95  * 1. Preamble:                             7 bytes;
96  * 2. Start of Frame Delimiter (SFD):       1 byte;
97  * 3. Frame Check Sequence (FCS):           4 bytes;
98  * 4. Inter Frame Gap (IFG):               12 bytes.
99  *
100  * The FCS is considered overhead only if not included in the packet
101  * length (field pkt_len of struct rte_mbuf).
102  *
103  * @see struct rte_sched_port_params
104  */
105 #ifndef RTE_SCHED_FRAME_OVERHEAD_DEFAULT
106 #define RTE_SCHED_FRAME_OVERHEAD_DEFAULT      24
107 #endif
108 
109 /**
110  * Congestion Management (CMAN) mode
111  *
112  * This is used for controlling the admission of packets into a packet queue or
113  * group of packet queues on congestion.
114  *
115  * The *Random Early Detection (RED)* algorithm works by proactively dropping
116  * more and more input packets as the queue occupancy builds up. When the queue
117  * is full or almost full, RED effectively works as *tail drop*. The *Weighted
118  * RED* algorithm uses a separate set of RED thresholds for each packet color.
119  *
120  * Similar to RED, Proportional Integral Controller Enhanced (PIE) randomly
121  * drops a packet at the onset of the congestion and tries to control the
122  * latency around the target value. The congestion detection, however, is based
123  * on the queueing latency instead of the queue length like RED. For more
124  * information, refer RFC8033.
125  */
126 enum rte_sched_cman_mode {
127 	RTE_SCHED_CMAN_RED, /**< Random Early Detection (RED) */
128 	RTE_SCHED_CMAN_PIE, /**< Proportional Integral Controller Enhanced (PIE) */
129 };
130 
131 /*
132  * Pipe configuration parameters. The period and credits_per_period
133  * parameters are measured in bytes, with one byte meaning the time
134  * duration associated with the transmission of one byte on the
135  * physical medium of the output port, with pipe or pipe traffic class
136  * rate (measured as percentage of output port rate) determined as
137  * credits_per_period divided by period. One credit represents one
138  * byte.
139  */
140 struct rte_sched_pipe_params {
141 	/** Token bucket rate (measured in bytes per second) */
142 	uint64_t tb_rate;
143 
144 	/** Token bucket size (measured in credits) */
145 	uint64_t tb_size;
146 
147 	/** Traffic class rates (measured in bytes per second) */
148 	uint64_t tc_rate[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
149 
150 	/** Enforcement period (measured in milliseconds) */
151 	uint64_t tc_period;
152 
153 	/** Best-effort traffic class oversubscription weight */
154 	uint8_t tc_ov_weight;
155 
156 	/** WRR weights of best-effort traffic class queues */
157 	uint8_t wrr_weights[RTE_SCHED_BE_QUEUES_PER_PIPE];
158 };
159 
160 /*
161  * Congestion Management configuration parameters.
162  */
163 struct rte_sched_cman_params {
164 	/** Congestion Management mode */
165 	enum rte_sched_cman_mode cman_mode;
166 
167 	union {
168 		/** RED parameters */
169 		struct rte_red_params red_params[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE][RTE_COLORS];
170 
171 		/** PIE parameters */
172 		struct rte_pie_params pie_params[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
173 	};
174 };
175 
176 /*
177  * Subport configuration parameters. The period and credits_per_period
178  * parameters are measured in bytes, with one byte meaning the time
179  * duration associated with the transmission of one byte on the
180  * physical medium of the output port, with pipe or pipe traffic class
181  * rate (measured as percentage of output port rate) determined as
182  * credits_per_period divided by period. One credit represents one
183  * byte.
184  */
185 struct rte_sched_subport_params {
186 	/** Number of subport pipes.
187 	 * The subport can enable/allocate fewer pipes than the maximum
188 	 * number set through struct port_params::n_max_pipes_per_subport,
189 	 * as needed, to avoid memory allocation for the queues of the
190 	 * pipes that are not really needed.
191 	 */
192 	uint32_t n_pipes_per_subport_enabled;
193 
194 	/** Packet queue size for each traffic class.
195 	 * All the pipes within the same subport share the similar
196 	 * configuration for the queues.
197 	 */
198 	uint16_t qsize[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
199 
200 	/** Pipe profile table.
201 	 * Every pipe is configured using one of the profiles from this table.
202 	 */
203 	struct rte_sched_pipe_params *pipe_profiles;
204 
205 	/** Profiles in the pipe profile table */
206 	uint32_t n_pipe_profiles;
207 
208 	/** Max allowed profiles in the pipe profile table */
209 	uint32_t n_max_pipe_profiles;
210 
211 	/** Congestion Management parameters
212 	 * If NULL the congestion management is disabled for the subport,
213 	 * otherwise proper parameters need to be provided.
214 	 */
215 	struct rte_sched_cman_params *cman_params;
216 };
217 
218 struct rte_sched_subport_profile_params {
219 	/** Token bucket rate (measured in bytes per second) */
220 	uint64_t tb_rate;
221 
222 	/** Token bucket size (measured in credits) */
223 	uint64_t tb_size;
224 
225 	/** Traffic class rates (measured in bytes per second) */
226 	uint64_t tc_rate[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
227 
228 	/** Enforcement period for rates (measured in milliseconds) */
229 	uint64_t tc_period;
230 };
231 
232 /** Subport statistics */
233 struct rte_sched_subport_stats {
234 	/** Number of packets successfully written */
235 	uint64_t n_pkts_tc[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
236 
237 	/** Number of packets dropped */
238 	uint64_t n_pkts_tc_dropped[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
239 
240 	/** Number of bytes successfully written for each traffic class */
241 	uint64_t n_bytes_tc[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
242 
243 	/** Number of bytes dropped for each traffic class */
244 	uint64_t n_bytes_tc_dropped[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
245 
246 	/** Number of packets dropped by congestion management scheme */
247 	uint64_t n_pkts_cman_dropped[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
248 };
249 
250 /** Queue statistics */
251 struct rte_sched_queue_stats {
252 	/** Packets successfully written */
253 	uint64_t n_pkts;
254 
255 	/** Packets dropped */
256 	uint64_t n_pkts_dropped;
257 
258 	/** Packets dropped by congestion management scheme */
259 	uint64_t n_pkts_cman_dropped;
260 
261 	/** Bytes successfully written */
262 	uint64_t n_bytes;
263 
264 	/** Bytes dropped */
265 	uint64_t n_bytes_dropped;
266 };
267 
268 /** Port configuration parameters. */
269 struct rte_sched_port_params {
270 	/** Name of the port to be associated */
271 	const char *name;
272 
273 	/** CPU socket ID */
274 	int socket;
275 
276 	/** Output port rate (measured in bytes per second) */
277 	uint64_t rate;
278 
279 	/** Maximum Ethernet frame size (measured in bytes).
280 	 * Should not include the framing overhead.
281 	 */
282 	uint32_t mtu;
283 
284 	/** Framing overhead per packet (measured in bytes) */
285 	uint32_t frame_overhead;
286 
287 	/** Number of subports */
288 	uint32_t n_subports_per_port;
289 
290 	/** subport profile table.
291 	 * Every pipe is configured using one of the profiles from this table.
292 	 */
293 	struct rte_sched_subport_profile_params *subport_profiles;
294 
295 	/** Profiles in the pipe profile table */
296 	uint32_t n_subport_profiles;
297 
298 	/** Max allowed profiles in the pipe profile table */
299 	uint32_t n_max_subport_profiles;
300 
301 	/** Maximum number of subport pipes.
302 	 * This parameter is used to reserve a fixed number of bits
303 	 * in struct rte_mbuf::sched.queue_id for the pipe_id for all
304 	 * the subports of the same port.
305 	 */
306 	uint32_t n_pipes_per_subport;
307 };
308 
309 /*
310  * Configuration
311  */
312 
313 /**
314  * Hierarchical scheduler port configuration
315  *
316  * @param params
317  *   Port scheduler configuration parameter structure
318  * @return
319  *   Handle to port scheduler instance upon success or NULL otherwise.
320  */
321 struct rte_sched_port *
322 rte_sched_port_config(struct rte_sched_port_params *params);
323 
324 /**
325  * Hierarchical scheduler port free
326  *
327  * @param port
328  *   Handle to port scheduler instance.
329  *   If port is NULL, no operation is performed.
330  */
331 void
332 rte_sched_port_free(struct rte_sched_port *port);
333 
334 /**
335  * Hierarchical scheduler pipe profile add
336  *
337  * @param port
338  *   Handle to port scheduler instance
339  * @param subport_id
340  *   Subport ID
341  * @param params
342  *   Pipe profile parameters
343  * @param pipe_profile_id
344  *   Set to valid profile id when profile is added successfully.
345  * @return
346  *   0 upon success, error code otherwise
347  */
348 int
349 rte_sched_subport_pipe_profile_add(struct rte_sched_port *port,
350 	uint32_t subport_id,
351 	struct rte_sched_pipe_params *params,
352 	uint32_t *pipe_profile_id);
353 
354 /**
355  * Hierarchical scheduler subport bandwidth profile add
356  * Note that this function is safe to use in runtime for adding new
357  * subport bandwidth profile as it doesn't have any impact on hierarchical
358  * structure of the scheduler.
359  * @param port
360  *   Handle to port scheduler instance
361  * @param profile
362  *   Subport bandwidth profile
363  * @param subport_profile_id
364  *   Subport profile id
365  * @return
366  *   0 upon success, error code otherwise
367  */
368 int
369 rte_sched_port_subport_profile_add(struct rte_sched_port *port,
370 	struct rte_sched_subport_profile_params *profile,
371 	uint32_t *subport_profile_id);
372 
373 /**
374  * Hierarchical scheduler subport configuration
375  * Note that this function is safe to use at runtime
376  * to configure subport bandwidth profile.
377  * @param port
378  *   Handle to port scheduler instance
379  * @param subport_id
380  *   Subport ID
381  * @param params
382  *   Subport configuration parameters. Must be non-NULL
383  *   for first invocation (i.e initialization) for a given
384  *   subport. Ignored (recommended value is NULL) for all
385  *   subsequent invocation on the same subport.
386  * @param subport_profile_id
387  *   ID of subport bandwidth profile
388  * @return
389  *   0 upon success, error code otherwise
390  */
391 int
392 rte_sched_subport_config(struct rte_sched_port *port,
393 	uint32_t subport_id,
394 	struct rte_sched_subport_params *params,
395 	uint32_t subport_profile_id);
396 
397 /**
398  * Hierarchical scheduler pipe configuration
399  *
400  * @param port
401  *   Handle to port scheduler instance
402  * @param subport_id
403  *   Subport ID
404  * @param pipe_id
405  *   Pipe ID within subport
406  * @param pipe_profile
407  *   ID of subport-level pre-configured pipe profile
408  * @return
409  *   0 upon success, error code otherwise
410  */
411 int
412 rte_sched_pipe_config(struct rte_sched_port *port,
413 	uint32_t subport_id,
414 	uint32_t pipe_id,
415 	int32_t pipe_profile);
416 
417 /**
418  * Hierarchical scheduler memory footprint size per port
419  *
420  * @param port_params
421  *   Port scheduler configuration parameter structure
422  * @param subport_params
423  *   Array of subport parameter structures
424  * @return
425  *   Memory footprint size in bytes upon success, 0 otherwise
426  */
427 uint32_t
428 rte_sched_port_get_memory_footprint(struct rte_sched_port_params *port_params,
429 	struct rte_sched_subport_params **subport_params);
430 
431 /*
432  * Statistics
433  */
434 
435 /**
436  * Hierarchical scheduler subport statistics read
437  *
438  * @param port
439  *   Handle to port scheduler instance
440  * @param subport_id
441  *   Subport ID
442  * @param stats
443  *   Pointer to pre-allocated subport statistics structure where the statistics
444  *   counters should be stored
445  * @param tc_ov
446  *   Pointer to pre-allocated RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE-entry array
447  *   where the oversubscription status for each of the subport traffic classes
448  *   should be stored.
449  * @return
450  *   0 upon success, error code otherwise
451  */
452 int
453 rte_sched_subport_read_stats(struct rte_sched_port *port,
454 	uint32_t subport_id,
455 	struct rte_sched_subport_stats *stats,
456 	uint32_t *tc_ov);
457 
458 /**
459  * Hierarchical scheduler queue statistics read
460  *
461  * @param port
462  *   Handle to port scheduler instance
463  * @param queue_id
464  *   Queue ID within port scheduler
465  * @param stats
466  *   Pointer to pre-allocated subport statistics structure where the statistics
467  *   counters should be stored
468  * @param qlen
469  *   Pointer to pre-allocated variable where the current queue length
470  *   should be stored.
471  * @return
472  *   0 upon success, error code otherwise
473  */
474 int
475 rte_sched_queue_read_stats(struct rte_sched_port *port,
476 	uint32_t queue_id,
477 	struct rte_sched_queue_stats *stats,
478 	uint16_t *qlen);
479 
480 /**
481  * Scheduler hierarchy path write to packet descriptor. Typically
482  * called by the packet classification stage.
483  *
484  * @param port
485  *   Handle to port scheduler instance
486  * @param pkt
487  *   Packet descriptor handle
488  * @param subport
489  *   Subport ID
490  * @param pipe
491  *   Pipe ID within subport
492  * @param traffic_class
493  *   Traffic class ID within pipe (0 .. RTE_SCHED_TRAFFIC_CLASS_BE)
494  * @param queue
495  *   Queue ID within pipe traffic class, 0 for high priority TCs, and
496  *   0 .. (RTE_SCHED_BE_QUEUES_PER_PIPE - 1) for best-effort TC
497  * @param color
498  *   Packet color set
499  */
500 void
501 rte_sched_port_pkt_write(struct rte_sched_port *port,
502 			 struct rte_mbuf *pkt,
503 			 uint32_t subport, uint32_t pipe, uint32_t traffic_class,
504 			 uint32_t queue, enum rte_color color);
505 
506 /**
507  * Scheduler hierarchy path read from packet descriptor (struct
508  * rte_mbuf). Typically called as part of the hierarchical scheduler
509  * enqueue operation. The subport, pipe, traffic class and queue
510  * parameters need to be pre-allocated by the caller.
511  *
512  * @param port
513  *   Handle to port scheduler instance
514  * @param pkt
515  *   Packet descriptor handle
516  * @param subport
517  *   Subport ID
518  * @param pipe
519  *   Pipe ID within subport
520  * @param traffic_class
521  *   Traffic class ID within pipe (0 .. RTE_SCHED_TRAFFIC_CLASS_BE)
522  * @param queue
523  *   Queue ID within pipe traffic class, 0 for high priority TCs, and
524  *   0 .. (RTE_SCHED_BE_QUEUES_PER_PIPE - 1) for best-effort TC
525  */
526 void
527 rte_sched_port_pkt_read_tree_path(struct rte_sched_port *port,
528 				  const struct rte_mbuf *pkt,
529 				  uint32_t *subport, uint32_t *pipe,
530 				  uint32_t *traffic_class, uint32_t *queue);
531 
532 enum rte_color
533 rte_sched_port_pkt_read_color(const struct rte_mbuf *pkt);
534 
535 /**
536  * Hierarchical scheduler port enqueue. Writes up to n_pkts to port
537  * scheduler and returns the number of packets actually written. For
538  * each packet, the port scheduler queue to write the packet to is
539  * identified by reading the hierarchy path from the packet
540  * descriptor; if the queue is full or congested and the packet is not
541  * written to the queue, then the packet is automatically dropped
542  * without any action required from the caller.
543  *
544  * @param port
545  *   Handle to port scheduler instance
546  * @param pkts
547  *   Array storing the packet descriptor handles
548  * @param n_pkts
549  *   Number of packets to enqueue from the pkts array into the port scheduler
550  * @return
551  *   Number of packets successfully enqueued
552  */
553 int
554 rte_sched_port_enqueue(struct rte_sched_port *port, struct rte_mbuf **pkts, uint32_t n_pkts);
555 
556 /**
557  * Hierarchical scheduler port dequeue. Reads up to n_pkts from the
558  * port scheduler and stores them in the pkts array and returns the
559  * number of packets actually read.  The pkts array needs to be
560  * pre-allocated by the caller with at least n_pkts entries.
561  *
562  * @param port
563  *   Handle to port scheduler instance
564  * @param pkts
565  *   Pre-allocated packet descriptor array where the packets dequeued
566  *   from the port
567  *   scheduler should be stored
568  * @param n_pkts
569  *   Number of packets to dequeue from the port scheduler
570  * @return
571  *   Number of packets successfully dequeued and placed in the pkts array
572  */
573 int
574 rte_sched_port_dequeue(struct rte_sched_port *port, struct rte_mbuf **pkts, uint32_t n_pkts);
575 
576 /**
577  * Hierarchical scheduler subport traffic class
578  * oversubscription enable/disable.
579  * This function should be called at the time of subport initialization.
580  *
581  * @param port
582  *   Handle to port scheduler instance
583  * @param subport_id
584  *   Subport ID
585  * @param tc_ov_enable
586  *  Boolean flag to enable/disable TC OV
587  * @return
588  *   0 upon success, error code otherwise
589  */
590 int
591 rte_sched_subport_tc_ov_config(struct rte_sched_port *port, uint32_t subport_id, bool tc_ov_enable);
592 
593 #ifdef __cplusplus
594 }
595 #endif
596 
597 #endif /* __INCLUDE_RTE_SCHED_H__ */
598