On Mon, 12 Jul 2010 22:46:59 -0700 Zach Pfeffer <zpfeffer@xxxxxxxxxxxxxx> wrote: > Joerg Roedel wrote: > > On Fri, Jul 02, 2010 at 12:33:51AM -0700, Zach Pfeffer wrote: > >> Daniel Walker wrote: > > > >>> So if we include this code which "map implementations" could you > >>> collapse into this implementations ? Generally , what currently existing > >>> code can VCMM help to eliminate? > >> In theory, it can eliminate all code the interoperates between IOMMU, > >> CPU and non-IOMMU based devices and all the mapping code, alignment, > >> mapping attribute and special block size support that's been > >> implemented. > > > > Thats a very abstract statement. Can you point to particular code files > > and give a rough sketch how it could be improved using VCMM? > > I can. Not to single out a particular subsystem, but the video4linux > code contains interoperation code to abstract the difference between > sg buffers, vmalloc buffers and physically contiguous buffers. The > VCMM is an attempt to provide a framework where these and all the > other buffer types can be unified. Why video4linux can't use the DMA API? Doing DMA with vmalloc'ed buffers is a thing that we should avoid (there are some exceptions like xfs though). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>