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

[Raghavendra K T]

On 2/13/2024 11:25 AM, Ankur Arora wrote:
> Hi,
>
> This series adds a new scheduling model PREEMPT_AUTO, which like
> PREEMPT_DYNAMIC allows dynamic switching between a none/voluntary/full
> preemption model. However, unlike PREEMPT_DYNAMIC, it doesn't depend
> on explicit preemption points for the voluntary models.
>
> The series is based on Thomas' original proposal which he outlined
> in [1], [2] and in his PoC [3].
>
> An earlier RFC version is at [4].

[...]

Hello Ankur,
Thank you for the series. Just giving a crisp summary since I am
expecting a respin of patchseries with minor changes suggested by
Thomas, Mark and a fix by Paul. and looking forward to test that.

I was able to test the current patchset rather in a different way.

On Milan, (2 node, 256 cpu,  512GB RAM), Did my regular benchmark
testing, to see if there are any surprises.

Will do more detailed testing/analysis w/ some of the scheduler specific
tests also after your respin.

Configuration tested.
a) Base kernel (6.7),
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
Graph500,  	   -6 			     +0
XSBench		   +1.7			     +0

Did kernbench etc test from Mel's mmtests suite also. Did not notice
much difference.

In summary benchmarks are mostly on positive side.

Thanks and Regards
- Raghu