[ewg] RE: [ofa-general] [PATCH] ib_send_bw -b can hang due to too few CQ entries

[Sean Hefty]

>Sure. Just above the call to ibv_create_cq(), ctx->rx_depth is set to
>	ctx->rx_depth = rx_depth + tx_depth
>but the rest of the code does ibv_post_send() and ibv_post_recv()
>based on ctx->tx_depth and ctx->rx_depth which means the CQ needs
>to be ctx->tx_depth + ctx->rx_depth big.

If the tx_depth is the same on both sides, why would there ever be more than the
initial tx_depth and rx_depth completions on the CQ?  How many receive
completions can there be on the CQ, and what throttles the sender? 

- Sean