On 11 10月 21 07:42:28, Christoph Hellwig wrote: > 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. Hi Christoph, thanks for your feedback. In this case, just simplify the code. 10 insertions(+), 31 deletions(-) dma_sync_ API is not called, I think the hardware may keep cache coherent directly or is a no cache system. No need to make perfermance compare. thanks Cai
