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

[Kent Overstreet]

On Thu, Sep 01, 2022 at 06:04:46PM -0700, 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).

Eh, I was hoping for better :)

> 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).
> 
> This is a recent optimization on the networking side:
> https://lore.kernel.org/linux-mm/20220825000506.239406-1-shakeelb@xxxxxxxxxx/
> 
> Maybe you can try to repeat this experiment.

I'd be more interested in a synthetic benchmark, if you know of any.