Re: [PATCH v2] dma-mapping: benchmark: pretend DMA is transmitting

[Christoph Hellwig]

On Fri, Feb 05, 2021 at 03:00:35PM +1300, Barry Song wrote:
> +	__u32 dma_trans_ns; /* time for DMA transmission in ns */
>  	__u64 expansion[10];	/* For future use */

We need to keep the struct size, so the expansion field needs to
shrink by the equivalent amount of data that is added in dma_trans_ns.