On 6/14/21 11:37 PM, Pavel Begunkov wrote: > There are two main lines intervened. The first one is pt.2 of ctx field > shuffling for better caching. There is a couple of things left on that > front. > > The second is optimising (assumably) rarely used offset-based timeouts > and draining. There is a downside (see 12/12), which will be fixed > later. In plans to queue a task_work clearing drain_used (under > uring_lock) from io_queue_deferred() once all drainee are gone. There is a much better way to disable it back: in io_drain_req(). The series is good to go, I'll patch on top later. > nops(batch=32): > 15.9 MIOPS vs 17.3 MIOPS > nullblk (irqmode=2 completion_nsec=0 submit_queues=16), no merges, no stat > 1002 KIOPS vs 1050 KIOPS > > Though the second test is very slow comparing to what I've seen before, > so might be not represantative. > > Pavel Begunkov (12): > io_uring: keep SQ pointers in a single cacheline > io_uring: move ctx->flags from SQ cacheline > io_uring: shuffle more fields into SQ ctx section > io_uring: refactor io_get_sqe() > io_uring: don't cache number of dropped SQEs > io_uring: optimise completion timeout flushing > io_uring: small io_submit_sqe() optimisation > io_uring: clean up check_overflow flag > io_uring: wait heads renaming > io_uring: move uring_lock location > io_uring: refactor io_req_defer() > io_uring: optimise non-drain path > > fs/io_uring.c | 226 +++++++++++++++++++++++++------------------------- > 1 file changed, 111 insertions(+), 115 deletions(-) > -- Pavel Begunkov
