Re: [PATCH] scsi: ibmvscsi_tgt: Use dma_alloc_coherent() instead of get_zeroed_page/dma_map_single()

[Christoph Hellwig]

On Mon, Oct 11, 2021 at 12:00:53AM +0800, Cai Huoqing wrote:
> Replacing get_zeroed_page/free_page/dma_map_single/dma_unmap_single()
> with dma_alloc_coherent/dma_free_coherent() helps to reduce
> code size, and simplify the code, and coherent DMA will not
> clear the cache every time.

This explanation does not make any sense whatsoever.  Please explain
why it would an show numbers.