Congestion Management APIs

Congestion Management or Back-pressure mechanism APIs are intended to handle the cases when the device is busy. These APIs ensures there is enough space on the ring before submitting a request.

Applications can query the appropriate ring on each instance and select any instance with enough space without creating any OpData structures.

All these API definitions are located in: $ICP_ROOT/quickassist/lookaside/access_layer/include/icp_sal_congestion_mgmt.h.

Important

Congestion Management APIs are not currently supported with the QAT2.0 driver.

icp_sal_SymGetInflightRequests

This function is used to fetch in-flight and max in-flight request counts for the given symmetric instance handle.

Syntax

CpaStatus icp_sal_SymGetInflightRequests(CpaInstanceHandle instanceHandle, Cpa32U *maxInflightRequests, Cpa32U *numInflightRequests);

Parameters

`instanceHandle`	Symmetric instance handle.
`*maxInflightRequests`	A pointer to the max in-flight request count.
`*numInflightRequests`	A pointer to the current in-flight request count.

Return Value

The icp_sal_SymGetInflightRequests function returns one of the following codes:

`CPA_STATUS_SUCCESS`	Successfully retrieved the request counts.
`CPA_STATUS_INVALID_PARAM`	Invalid parameter passed to the function.
`CPA_STATUS_FAIL`	Indicates a failure.

icp_sal_AsymGetInflightRequests

This function is used to fetch in-flight and max in-flight request counts for the given asymmetric instance handle.

Syntax

CpaStatus icp_sal_AsymGetInflightRequests(CpaInstanceHandle instanceHandle, Cpa32U *maxInflightRequests, Cpa32U *numInflightRequests);

Parameters

`instanceHandle`	Asymmetric instance handle.
`*maxInflightRequests`	A pointer to the max in-flight request count.
`*numInflightRequests`	A pointer to the current in-flight request count.

Return Value

The icp_sal_AsymGetInflightRequests function returns one of the following codes:

`CPA_STATUS_SUCCESS`	Successfully retrieved the request counts.
`CPA_STATUS_INVALID_PARAM`	Invalid parameter passed to the function.
`CPA_STATUS_FAIL`	Indicates a failure.

icp_sal_dp_SymGetInflightRequests

This data plane function is used to fetch in-flight and max in-flight request counts for the given symmetric instance handle.

Syntax

CpaStatus icp_sal_dp_SymGetInflightRequests(CpaInstanceHandle instanceHandle, Cpa32U *maxInflightRequests, Cpa32U *numInflightRequests);

Parameters

`instanceHandle`	Symmetric instance handle.
`*maxInflightRequests`	A pointer to the max in-flight request count.
`*numInflightRequests`	A pointer to the current in-flight request count.

Return Value

The icp_sal_dp_SymGetInflightRequests function returns one of the following codes:

`CPA_STATUS_SUCCESS`	Successfully retrieved the request counts.
`CPA_STATUS_INVALID_PARAM`	Invalid parameter passed to the function.
`CPA_STATUS_FAIL`	Indicates a failure.