odp_bp_param_t Struct Reference

Back pressure (BP) More...

#include <classification.h>

Collaboration diagram for odp_bp_param_t:

Data Fields
odp_bool_t	enable
	A boolean to enable Back pressure When true, back pressure is enabled and configured with the BP parameters. More...
odp_threshold_t	threshold
	Threshold value for back pressure. More...
uint8_t	pfc_level
	PFC priority level. More...

Detailed Description

Back pressure (BP)

When back pressure is enabled, HW can send back pressure to the remote peer indicating resource shortage. Depending on the implementation, back pressure can be asserted when the fill level of the destination queue of a CoS exceeds the configured threshold or when the utilization of the packet pool associated with a CoS exceeds the configured threshold.

If multiple CoSes configure back pressure for the same pktio, pool/queue and pfc level, then back pressure is sent as long as any of the CoSes assert back pressure. There does not have to be packets flowing through a CoS node for the CoS to assert back pressure, because packets may be directed to the same queue/pool by some other CoS node (which might not even have backpressure configured), some other ODP component or the ODP application.

Conceptually, a configured CoS hierarchy determines unique global back pressure threshold for each (pktio, queue/pool, pfc_level)-tuple. The back pressure configuration in a CoS affects the global thresholds that have the same queue/pool as configured in the Cos, the same pfc_level (if PFC is enabled) and a pktio that is a connected to the CoS. One CoS can affect multiple global thresholds and one global threshold can be affected by multiple CoSes (in which case the minimum of the configured thresholds is used).

Definition at line 410 of file api/spec/classification.h.

Field Documentation

enable

odp_bool_t odp_bp_param_t::enable

A boolean to enable Back pressure When true, back pressure is enabled and configured with the BP parameters.

Otherwise BP parameters are ignored. Default value is false.

Definition at line 416 of file api/spec/classification.h.

threshold

odp_threshold_t odp_bp_param_t::threshold

Threshold value for back pressure.

BP is enabled when the resource usage is equal to or greater than the max backpressure threshold. Min threshold parameters are ignored for BP configuration.

See also

odp_red_param_t for 'resource usage' documentation.

Definition at line 424 of file api/spec/classification.h.

pfc_level

uint8_t odp_bp_param_t::pfc_level

PFC priority level.

When enabled (ODP_PKTIO_LINK_PFC_ON), PFC frames are generated when the above threshold is exceeded. The generated frames request the receiver to temporary halt transmission of traffic on this priority level (0 .. 7).

Definition at line 433 of file api/spec/classification.h.

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The documentation for this struct was generated from the following file:

• api/spec/classification.h