On Tue, Oct 27, 2026 at 07:03:29AM -0600, Jens Axboe wrote: > On 10/27/26 3:08 AM, Li Wang wrote: > > From: Mengmeng Zhao <[email protected]> > > > > This patch introduces a driver that allows moving data between a GPU > > dma-buf and a regular file on NVME without staging it through the page > > cache. Userspace registers the GPU dma-buf with the device, then issues > > read and write requests via the device's ioctls. Each transfer is direct > > I/O: an ITER_DMABUF_MAP iterator is passed to the file's read_iter or > > write_iter, and the filesystem's iomap path submits REQ_DMABUF bios that > > already carry the dma addresses. > > > > Signed-off-by: Mengmeng Zhao <[email protected]> > > Signed-off-by: Li Wang <[email protected]> > > --- > > .../userspace-api/ioctl/ioctl-number.rst | 2 + > > drivers/dma-buf/dma-buf-io.c | 3 + > > drivers/misc/Kconfig | 16 + > > drivers/misc/Makefile | 1 + > > drivers/misc/fgds.c | 506 ++++++++++++++++++ > > fs/iomap/buffered-io.c | 11 + > > fs/iomap/direct-io.c | 23 +- > > fs/xfs/xfs_file.c | 4 + > > include/linux/iov_iter.h | 4 + > > include/uapi/linux/fgds.h | 124 +++++ > > lib/iov_iter.c | 1 + > > mm/filemap.c | 22 +- > > 12 files changed, 713 insertions(+), 4 deletions(-) > > create mode 100644 drivers/misc/fgds.c > > create mode 100644 include/uapi/linux/fgds.h > > What's the point of this, when you can just use io_uring to do > the same?!
Agreed, I thought that the summary of the last round of reviews was "this isn't needed at all". Li, what changed from that? thanks, greg k-h
