From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Subject: Re: [RFC 0/4] completion locking optimisation feature
Date: Fri, 18 Mar 2022 15:00:56 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
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
next prev parent reply other threads:[~2022-03-18 15:02 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-18 13:52 [RFC 0/4] completion locking optimisation feature Pavel Begunkov
2022-03-18 13:52 ` [PATCH 1/4] io_uring: get rid of raw fill cqe in kill_timeout Pavel Begunkov
2022-03-18 13:52 ` [PATCH 2/4] io_uring: get rid of raw fill_cqe in io_fail_links Pavel Begunkov
2022-03-18 13:52 ` [PATCH 3/4] io_uring: remove raw fill_cqe from linked timeout Pavel Begunkov
2022-03-18 13:52 ` [PATCH 4/4] io_uring: optimise compl locking for non-shared rings Pavel Begunkov
2022-03-18 14:54 ` Jens Axboe
2022-03-18 15:13 ` Pavel Begunkov
2022-03-18 15:21 ` Jens Axboe
2022-03-18 15:32 ` Pavel Begunkov
2022-03-18 16:06 ` Jens Axboe
2022-03-18 14:42 ` [RFC 0/4] completion locking optimisation feature Pavel Begunkov
2022-03-18 14:52 ` Jens Axboe
2022-03-18 15:00 ` Pavel Begunkov [this message]
2022-03-18 15:22 ` Jens Axboe
2022-03-18 15:34 ` Pavel Begunkov
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