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.