Design question: what is comm->planner.tmpCollWorkQueue used for?

[YconquestY]

Hello, I have a question on the design philosophy of NCCL.

The call sequence of some "important" functions in groupLaunch is: ncclPrepareTasks $\rightarrow$ ncclPrepareTasks $\rightarrow \cdots \rightarrow$ ncclPrepareTasks $\rightarrow$ ncclTasksRegAndEnqueue $\rightarrow$ ncclTasksRegAndEnqueue $\rightarrow \cdots \rightarrow$ ncclTasksRegAndEnqueue $\rightarrow$ doLaunches.

ncclPrepareTasks is called repeatedly, wherein NVLS-relates tasks are put to a work queue, tmpCollWorkQueue.

Later, ncclTasksRegAndEnqueue is also called in a loop. It dequeues tmpCollWorkQueue and push whatever popped to collWorkQueue.

I do not understand the use of tmpCollWorkQueue. It seems that it serves as software cache for NVLS work. Now that NVLS work will be pushed to collWorkQueue anyway, why don't we just let ncclTasksRegsAndEnqueue do the job?