Hi Jens,
That is interesting. Recently I sent an rfc related to epoll uring:
https://lore.kernel.org/lkml/20190109164025.24554-1-rpenyaev@xxxxxxx
which can be mapped to userspace and all ready events can be consumed
from it directly. I am wondering, is it possible to make some common
API for all kind of ready events / urings, or it doesn't make any
sense?
--
Roman
On 2019-01-10 03:43, Jens Axboe wrote:
Here's v2 of the io_uring interface. See the v1 posting for some more
info:
https://lore.kernel.org/linux-block/20190108165645.19311-1-axboe@xxxxxxxxx/
The data structures changed, to improve the symmetry of the submission
and completion side. The io_uring_iocb is now io_uring_sqe, but it
otherwise remains the same as before. Ditto on the completion side,
where io_uring_event is now io_uring_cqe.
I've updated the fio io_uring test app, and the io_uring engine. The
liburing git repo has also been adapted to the various changes since
the
v1 posting. As a reminder, the liburing git repo contains some helpers
for doing IO without having to muck with the ring directly, setting up
an io_uring context, etc. Clone that here:
git://git.kernel.dk/liburing
In terms of usage, there's also a small test app here:
http://git.kernel.dk/cgit/fio/plain/t/io_uring.c
and the liburing repo has a few test apps in test/ as well.
Patches are aginst 5.0-rc1, but can also be found here:
git://git.kernel.dk/linux-block io_uring
Changes since v1:
- Fail IORING_OP_{READ,WRITE}_FIXED if not configured
- Fix ctx drop ref issue on failure to close ring_fd when sq thread/wq
are in use
- Move to separate Kconfig entry (CONFIG_IO_URING)
- Add SPDX headers
- Drop gcc ism of zero sized arrays
- Rename io_uring_iocb -> io_uring_sqe
- Rename io_uring_event -> io_uring_cqe
- Drop needless io_event_ring and io_iocb_ring structures
- Drop ctx->max_reqs, use ->sq_entries
- Drop unused ->ring_lock
- Drop io_ring_ctx slab cache
- Fix state batched kiocb alloc failure to put ctx
- Fix missing write ordering barrier when filling in the cqe
- Drop io_req_init()
- Various renames
- Fix a few lines that were too long
- Address other minor review comments
- Fix IORING_SETUP_SQPOLL being set without IORING_SETUP_SQTHREAD
- Drop IORING_SETUP_FIXEDBUFS, iovecs being non-NULL is enough
- Fix error handling free of ctx in setup path
- Change standard read/write commands to be iov based READV/WRITEV
- Pass in struct sqe_submit instead of separate sqe/index everywhere
- Fix reap of polled events on fops->release()
- Lock uring for sq thread polling
- Don't grab ->completion_lock for polled IO cqe filling
- Fix ev_flags vs flags typo
- Consolidate parts of the io_ring_ctx alignment
Documentation/filesystems/vfs.txt | 3 +
arch/x86/entry/syscalls/syscall_64.tbl | 2 +
block/bio.c | 59 +-
fs/Makefile | 1 +
fs/block_dev.c | 19 +-
fs/file.c | 15 +-
fs/file_table.c | 9 +-
fs/gfs2/file.c | 2 +
fs/io_uring.c | 1890 ++++++++++++++++++++++++
fs/iomap.c | 48 +-
fs/xfs/xfs_file.c | 1 +
include/linux/bio.h | 14 +
include/linux/blk_types.h | 1 +
include/linux/file.h | 2 +
include/linux/fs.h | 6 +-
include/linux/iomap.h | 1 +
include/linux/syscalls.h | 5 +
include/uapi/linux/io_uring.h | 114 ++
init/Kconfig | 8 +
kernel/sys_ni.c | 2 +
20 files changed, 2163 insertions(+), 39 deletions(-)
