Re: [PATCH 00/30] PREEMPT_AUTO: support lazy rescheduling

[Raghavendra K T]

On 2/21/2024 10:45 PM, Thomas Gleixner wrote:
> On Wed, Feb 21 2024 at 17:53, Raghavendra K T wrote:
> > Configuration tested.
> > a) Base kernel (6.7),
>
> Which scheduling model is the baseline using?
>
> > b) patched with PREEMPT_AUTO voluntary preemption.
> > c) patched with PREEMPT_DYNAMIC voluntary preemption.
> >
> > Workloads I tested and their %gain,
> >                      case b                   case c
> > NAS                +2.7                    +1.9
> > Hashjoin,          +0			     +0
> > XSBench	     +1.7		     +0
> > Graph500,  	     -6 		     +0
>
> The Graph500 stands out. Needs some analysis.

Hello Thomas, Ankur,

Because of high stdev I saw with the runs for Graph500, continued to 
take results with more iterations.

Here is the result. It does not look like there is a concern here.

(you can see the *min* side of preempt-auto case which could have got 
the negative result in the analysis, But I should have posted stdev 
along with that. Sorry for not being louder there.).

Overall this looks good. some time better but all within noise level.

Benchmark = Graph500

x  6.7.0+
+  6.7.0-preempt-auto+

    N           Min           Max        Median           Avg        Stddev
x  15 6.7165689e+09 7.7607743e+09 7.2213638e+09 7.2759563e+09 3.3353312e+08
+  15 6.4856432e+09  7.942607e+09 7.3115082e+09 7.3386124e+09 4.6474773e+08

No difference proven at 80.0% confidence
No difference proven at 95.0% confidence
No difference proven at 99.0% confidence

Thanks and Regards
- Raghu