rte_sched.h File Reference

#include <sys/types.h>
#include <rte_mbuf.h>
#include <rte_meter.h>

Data Structures
struct	rte_sched_subport_params
struct	rte_sched_subport_stats
struct	rte_sched_pipe_params
struct	rte_sched_queue_stats
struct	rte_sched_port_params
struct	rte_sched_port_hierarchy

Macros
#define	RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE   4
#define	RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS   4
#define	RTE_SCHED_QUEUES_PER_PIPE
#define	RTE_SCHED_PIPE_PROFILES_PER_PORT   256
#define	RTE_SCHED_FRAME_OVERHEAD_DEFAULT   24

Functions
struct rte_sched_port *	rte_sched_port_config (struct rte_sched_port_params *params)
void	rte_sched_port_free (struct rte_sched_port *port)
int	rte_sched_subport_config (struct rte_sched_port *port, uint32_t subport_id, struct rte_sched_subport_params *params)
int	rte_sched_pipe_config (struct rte_sched_port *port, uint32_t subport_id, uint32_t pipe_id, int32_t pipe_profile)
uint32_t	rte_sched_port_get_memory_footprint (struct rte_sched_port_params *params)
int	rte_sched_subport_read_stats (struct rte_sched_port *port, uint32_t subport_id, struct rte_sched_subport_stats *stats, uint32_t *tc_ov)
int	rte_sched_queue_read_stats (struct rte_sched_port *port, uint32_t queue_id, struct rte_sched_queue_stats *stats, uint16_t *qlen)
static void	rte_sched_port_pkt_write (struct rte_mbuf *pkt, uint32_t subport, uint32_t pipe, uint32_t traffic_class, uint32_t queue, enum rte_meter_color color)
static void	rte_sched_port_pkt_read_tree_path (struct rte_mbuf *pkt, uint32_t *subport, uint32_t *pipe, uint32_t *traffic_class, uint32_t *queue)
int	rte_sched_port_enqueue (struct rte_sched_port *port, struct rte_mbuf **pkts, uint32_t n_pkts)
int	rte_sched_port_dequeue (struct rte_sched_port *port, struct rte_mbuf **pkts, uint32_t n_pkts)

Detailed Description

RTE Hierarchical Scheduler

The hierarchical scheduler prioritizes the transmission of packets from different users and traffic classes according to the Service Level Agreements (SLAs) defined for the current network node.

The scheduler supports thousands of packet queues grouped under a 5-level hierarchy:

1. Port:
   • Typical usage: output Ethernet port;
   • Multiple ports are scheduled in round robin order with equal priority;
2. Subport:
   • Typical usage: group of users;
   • Traffic shaping using the token bucket algorithm (one bucket per subport);
   • Upper limit enforced per traffic class at subport level;
   • Lower priority traffic classes able to reuse subport bandwidth currently unused by higher priority traffic classes of the same subport;
   • When any subport traffic class is oversubscribed (configuration time event), the usage of subport member pipes with high demand for that traffic class pipes is truncated to a dynamically adjusted value with no impact to low demand pipes;
3. Pipe:
   • Typical usage: individual user/subscriber;
   • Traffic shaping using the token bucket algorithm (one bucket per pipe);
4. Traffic class:
   • Traffic classes of the same pipe handled in strict priority order;
   • Upper limit enforced per traffic class at the pipe level;
   • Lower priority traffic classes able to reuse pipe bandwidth currently unused by higher priority traffic classes of the same pipe;
5. Queue:
   • Typical usage: queue hosting packets from one or multiple connections of same traffic class belonging to the same user;
   • Weighted Round Robin (WRR) is used to service the queues within same pipe traffic class.

Macro Definition Documentation

#define RTE_SCHED_FRAME_OVERHEAD_DEFAULT   24

Ethernet framing overhead. Overhead fields per Ethernet frame:

1. Preamble: 7 bytes;
2. Start of Frame Delimiter (SFD): 1 byte;
3. Frame Check Sequence (FCS): 4 bytes;
4. Inter Frame Gap (IFG): 12 bytes. The FCS is considered overhead only if not included in the packet length (field pkt_len of struct rte_mbuf).

#define RTE_SCHED_PIPE_PROFILES_PER_PORT   256

Maximum number of pipe profiles that can be defined per port. Compile-time configurable.

#define RTE_SCHED_QUEUES_PER_PIPE

Value:

(RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE *     \
        RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS)

Number of queues per pipe.

#define RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS   4

Number of queues per pipe traffic class. Cannot be changed.

#define RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE   4

Random Early Detection (RED) Number of traffic classes per pipe (as well as subport). Cannot be changed.

Function Documentation

int rte_sched_pipe_config	(	struct rte_sched_port *	port,
		uint32_t	subport_id,
		uint32_t	pipe_id,
		int32_t	pipe_profile
	)

Hierarchical scheduler pipe configuration

Parameters

port	Handle to port scheduler instance
subport_id	Subport ID
pipe_id	Pipe ID within subport
pipe_profile	ID of port-level pre-configured pipe profile

Returns

0 upon success, error code otherwise

struct rte_sched_port* rte_sched_port_config ( struct rte_sched_port_params *  params )

read

Hierarchical scheduler port configuration

Parameters

params

Port scheduler configuration parameter structure

Returns

Handle to port scheduler instance upon success or NULL otherwise.

int rte_sched_port_dequeue	(	struct rte_sched_port *	port,
		struct rte_mbuf **	pkts,
		uint32_t	n_pkts
	)

Hierarchical scheduler port dequeue. Reads up to n_pkts from the port scheduler and stores them in the pkts array and returns the number of packets actually read. The pkts array needs to be pre-allocated by the caller with at least n_pkts entries.

Parameters

port	Handle to port scheduler instance
pkts	Pre-allocated packet descriptor array where the packets dequeued from the port scheduler should be stored
n_pkts	Number of packets to dequeue from the port scheduler

Returns

Number of packets successfully dequeued and placed in the pkts array

int rte_sched_port_enqueue	(	struct rte_sched_port *	port,
		struct rte_mbuf **	pkts,
		uint32_t	n_pkts
	)

Hierarchical scheduler port enqueue. Writes up to n_pkts to port scheduler and returns the number of packets actually written. For each packet, the port scheduler queue to write the packet to is identified by reading the hierarchy path from the packet descriptor; if the queue is full or congested and the packet is not written to the queue, then the packet is automatically dropped without any action required from the caller.

Parameters

port	Handle to port scheduler instance
pkts	Array storing the packet descriptor handles
n_pkts	Number of packets to enqueue from the pkts array into the port scheduler

Returns

Number of packets successfully enqueued

void rte_sched_port_free

(

struct rte_sched_port *

port

)

Hierarchical scheduler port free

Parameters

port	Handle to port scheduler instance

uint32_t rte_sched_port_get_memory_footprint

(

struct rte_sched_port_params *

params

)

Hierarchical scheduler memory footprint size per port

Parameters

params

Port scheduler configuration parameter structure

Returns

Memory footprint size in bytes upon success, 0 otherwise

static void rte_sched_port_pkt_read_tree_path ( struct rte_mbuf *  pkt, uint32_t *  subport, uint32_t *  pipe, uint32_t *  traffic_class, uint32_t *  queue  )

inlinestatic

Scheduler hierarchy path read from packet descriptor (struct rte_mbuf). Typically called as part of the hierarchical scheduler enqueue operation. The subport, pipe, traffic class and queue parameters need to be pre-allocated by the caller.

Parameters

pkt	Packet descriptor handle
subport	Subport ID
pipe	Pipe ID within subport
traffic_class	Traffic class ID within pipe (0 .. 3)
queue	Queue ID within pipe traffic class (0 .. 3)

static void rte_sched_port_pkt_write ( struct rte_mbuf *  pkt, uint32_t  subport, uint32_t  pipe, uint32_t  traffic_class, uint32_t  queue, enum rte_meter_color  color  )

inlinestatic

Scheduler hierarchy path write to packet descriptor. Typically called by the packet classification stage.

Parameters

pkt	Packet descriptor handle
subport	Subport ID
pipe	Pipe ID within subport
traffic_class	Traffic class ID within pipe (0 .. 3)
queue	Queue ID within pipe traffic class (0 .. 3)

int rte_sched_queue_read_stats	(	struct rte_sched_port *	port,
		uint32_t	queue_id,
		struct rte_sched_queue_stats *	stats,
		uint16_t *	qlen
	)

Hierarchical scheduler queue statistics read

Parameters

port	Handle to port scheduler instance
queue_id	Queue ID within port scheduler
stats	Pointer to pre-allocated subport statistics structure where the statistics counters should be stored
qlen	Pointer to pre-allocated variable where the current queue length should be stored.

Returns

0 upon success, error code otherwise

int rte_sched_subport_config	(	struct rte_sched_port *	port,
		uint32_t	subport_id,
		struct rte_sched_subport_params *	params
	)

Hierarchical scheduler subport configuration

Parameters

port	Handle to port scheduler instance
subport_id	Subport ID
params	Subport configuration parameters

Returns

0 upon success, error code otherwise

int rte_sched_subport_read_stats	(	struct rte_sched_port *	port,
		uint32_t	subport_id,
		struct rte_sched_subport_stats *	stats,
		uint32_t *	tc_ov
	)

Hierarchical scheduler subport statistics read

Parameters

port	Handle to port scheduler instance
subport_id	Subport ID
stats	Pointer to pre-allocated subport statistics structure where the statistics counters should be stored
tc_ov	Pointer to pre-allocated 4-entry array where the oversubscription status for each of the 4 subport traffic classes should be stored.

Returns

0 upon success, error code otherwise