On 3/18/22 14:52, Jens Axboe wrote:
On 3/18/22 8:42 AM, Pavel Begunkov wrote:
On 3/18/22 13:52, Pavel Begunkov wrote:
A WIP feature optimising out CQEs posting spinlocking for some use cases.
For a more detailed description see 4/4.
Quick benchmarking with fio/t/io_uring nops gives extra 4% to throughput for
QD=1, and ~+2.5% for QD=4.
Non-io_uring overhead (syscalls + userspace) takes ~60% of all execution
time, so the percentage should quite depend on the CPU and the kernel config.
Likely to be more than 4% for a faster setup.
fwiw, was also usingIORING_ENTER_REGISTERED_RING, if it's not yet included
in the upstream version of the tool.
But that seems to be exclusive of using PRIVATE_CQ?
No, it's not. Let me ask to clarify the description and so, why do you
think it is exclusive?
Also, want to play after to see if we can also avoid taking uring_lock.
That would certainly also be interesting!
--
Pavel Begunkov
