NAME¶

ibv_query_qp_data_in_order - check if qp data is guaranteed to be in order.

SYNOPSIS¶

#include <infiniband/verbs.h>
int ibv_query_qp_data_in_order(struct ibv_qp *qp, enum ibv_wr_opcode op, uint32_t flags);
    

DESCRIPTION¶

ibv_query_qp_data_in_order() Checks whether WQE data is guaranteed to be written in-order, and thus reader may poll for data instead of poll for completion. This function indicates data is written in-order within each WQE, but cannot be used to determine ordering between separate WQEs. This function describes ordering at the receiving side of the QP, not the sending side.

ARGUMENTS¶

qp

The local queue pair (QP) to query.
    

op

The operation type to query about. Different operation types may write data in a different order.
    

flags

Flags are used to select a query type. Supported values:

IBV_QUERY_QP_DATA_IN_ORDER_RETURN_CAPS - Query for supported capabilities and return a capabilities vector.

Passing 0 is equivalent to using IBV_QUERY_QP_DATA_IN_ORDER_RETURN_CAPS and checking for IBV_QUERY_QP_DATA_IN_ORDER_WHOLE_MSG support.

RETURN VALUE¶

ibv_query_qp_data_in_order() Return value is determined by flags. For each capability bit, 1 is returned if the data is guaranteed to be written in-order for selected operation and type, 0 otherwise. If IBV_QUERY_QP_DATA_IN_ORDER_RETURN_CAPS flag is used, return value can consist of following capabilities:

IBV_QUERY_QP_DATA_IN_ORDER_WHOLE_MSG - All data is being written in order.

IBV_QUERY_QP_DATA_IN_ORDER_ALIGNED_128_BYTES - Each 128 bytes aligned block is being written in order.

If flags is 0, the function will return 1 if IBV_QUERY_QP_DATA_IN_ORDER_WHOLE_MSG is supported and 0 otherwise.

NOTES¶

Return value is valid only when the data is read by the CPU and relaxed ordering MR is not the target of the transfer.

SEE ALSO¶

ibv_query_qp(3)

AUTHOR¶

Patrisious Haddad <phaddad@nvidia.com>

Yochai Cohen <yochai@nvidia.com>