Re: [RFC PATCH 00/30] Code tagging framework and applications

Jens Axboe
2022-09-02T12:02:26Z

On 9/1/22 7:04 PM, Roman Gushchin wrote:
> On Thu, Sep 01, 2022 at 08:17:47PM -0400, Kent Overstreet wrote:
>> On Thu, Sep 01, 2022 at 03:53:57PM -0700, Roman Gushchin wrote:
>>> I'd suggest to run something like iperf on a fast hardware. And maybe some
>>> io_uring stuff too. These are two places which were historically most sensitive
>>> to the (kernel) memory accounting speed.
>>
>> I'm getting wildly inconsistent results with iperf.
>>
>> io_uring-echo-server and rust_echo_bench gets me:
>> Benchmarking: 127.0.0.1:12345
>> 50 clients, running 512 bytes, 60 sec.
>>
>> Without alloc tagging: 120547 request/sec
>> With: 116748 request/sec
>>
>> https://github.com/frevib/io_uring-echo-server
>> https://github.com/haraldh/rust_echo_bench
>>
>> How's that look to you? Close enough? :)
>
> Yes, this looks good (a bit too good).
>
> I'm not that familiar with io_uring, Jens and Pavel should have a better idea
> what and how to run (I know they've workarounded the kernel memory accounting
> because of the performance in the past, this is why I suspect it might be an
> issue here as well).

io_uring isn't alloc+free intensive on a per request basis anymore, it
would not be a good benchmark if the goal is to check for regressions in
that area.

--
Jens Axboe