On Fri, Jan 03, 2025 at 02:12:36PM -0800, Bart Van Assche wrote: > On 1/2/25 6:01 PM, Ming Lei wrote: > > But why does DMA segment size have to be >= PAGE_SIZE(4KB, 64KB)? > > From the description of patch 5/8 of my patch series: "If the segment > size is smaller than the page size there may be multiple segments per > bvec even if a bvec only contains a single page." The current block > layer implementation is based on the assumption that a single page > fits in a single DMA segment. Please take a look at patch 5/8 of my > patch series. While that addresses a smaller segment then page size this still leaves open the question of if a dma segment can be larger than page size, given our adoption of folios I don't see why we would constrain ourselves to a page size. I already have PoC code which enables this. Luis
