On Tue, May 07, 2024 at 12:22:36AM +0800, Ming Lei wrote: > Hello, > > The 1st 4 patches are cleanup, and prepare for adding sqe group. > > The 5th patch supports generic sqe group which is like link chain, but > allows each sqe in group to be issued in parallel, so N:M dependency can be > supported with sqe group & io link together. > > The 6th patch supports one variant of sqe group: allow members to depend > on group leader, so that kernel resource lifetime can be aligned with > group leader or group, then any kernel resource can be shared in this > sqe group, and can be used in generic device zero copy. > > The 7th & 8th patches supports providing sqe group buffer via the sqe > group variant. > > The 9th patch supports ublk zero copy based on io_uring providing sqe > group buffer. > > Tests: > > 1) pass liburing test > - make runtests > > 2) write/pass two sqe group test cases: > > https://github.com/axboe/liburing/compare/master...ming1:liburing:sqe_group_v2 > > covers related sqe flags combination and linking groups, both nop and > one multi-destination file copy. > > 3) ublksrv zero copy: > > ublksrv userspace implements zero copy by sqe group & provide group > kbuf: > > git clone https://github.com/ublk-org/ublksrv.git -b group-provide-buf_v2 > make test T=loop/009:nbd/061:nbd/062 #ublk zc tests > > When running 64KB block size test on ublk-loop('ublk add -t loop --buffered_io -f $backing'), > it is observed that perf can be doubled. > > Any comments are welcome! > > V2: > - add generic sqe group, suggested by Kevin Wolf > - add REQ_F_SQE_GROUP_DEP which is based on IOSQE_SQE_GROUP, for sharing > kernel resource in group wide, suggested by Kevin Wolf > - remove sqe ext flag, and use the last bit for IOSQE_SQE_GROUP(Pavel), > in future we still can extend sqe flags with one uring context flag > - initialize group requests via submit state pattern, suggested by Pavel > - all kinds of cleanup & bug fixes Please ignore V2, and will send V3 with simplification & cleanup, and many fixes on error handling code path. Thanks, Ming
