Hi List, I'm CM Lee. I'm developing a custom character device managing pcie dma. I've tried to use io uring for the char device which supports readv and writev with synchronous and blocking manner and seek. When I use a io uring with IORING_SETUP_IOPOLL and IORING_SETUP_SQPOLL for reducing syscall overhead, a readv of the char device driver seems to be not called. So I added a_ops->direct_IO when the device is opened with O_DIRECT. But the result was the same. This is my question. Q1: Does io uring support a character device ? Q2: Is it better to reimplement a device driver as block device type ? Thanks, CM
