On Fri, Jan 03, 2025 at 06:15:55PM -0800, Bart Van Assche wrote: > On 1/3/25 5:47 PM, Luis Chamberlain wrote: > > 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, > Hmm ... aren't max_segment_size values that are larger than the page > size supported since day one of the Linux kernel? Or are you perhaps > referring to Ming's multi-page bvec patch series that was merged about > six years ago? Try aiming high for a single 2 MiB for a single IO on x86_64 on NVMe, that is currently not possible. At the max 128 NVMe number of DMA segments, and we have 4 KiB per DMA segment, for a 512 KiB IO limit. Should multi-page bvec enable to lift this? Luis
