+
+* **CDEV_SCHED_MODE_PKT_SIZE_DISTR:**
+
+ *Initialization mode parameter*: **packet-size-distr**
+
+ Packet-size based distribution mode, which works with 2 slaves, the primary
+ slave and the secondary slave, and distributes the enqueued crypto
+ operations to them based on their data lengths. A crypto operation will be
+ distributed to the primary slave if its data length is equal to or bigger
+ than the designated threshold, otherwise it will be handled by the secondary
+ slave.
+
+ A typical usecase in this mode is with the QAT cryptodev as the primary and
+ a software cryptodev as the secondary slave. This may help applications to
+ process additional crypto workload than what the QAT cryptodev can handle on
+ its own, by making use of the available CPU cycles to deal with smaller
+ crypto workloads.
+
+ The threshold is set to 128 bytes by default. It can be updated by calling
+ function **rte_cryptodev_scheduler_option_set**. The parameter of
+ **option_type** must be **CDEV_SCHED_OPTION_THRESHOLD** and **option** should
+ point to a rte_cryptodev_scheduler_threshold_option structure filled with
+ appropriate threshold value. Please NOTE this threshold has be a power-of-2
+ unsigned integer.
+
+* **CDEV_SCHED_MODE_FAILOVER:**
+
+ *Initialization mode parameter*: **fail-over**
+
+ Fail-over mode, which works with 2 slaves, the primary slave and the
+ secondary slave. In this mode, the scheduler will enqueue the incoming
+ crypto operation burst to the primary slave. When one or more crypto
+ operations fail to be enqueued, then they will be enqueued to the secondary
+ slave.