Re: [PATCH] sched/fair: Enable group_asym_packing in find_idlest_group

From: Srikar Dronamraju
Date: Thu Dec 14 2023 - 23:10:59 EST


* Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> [2023-10-18 21:20:35]:

Hi Ingo, Peter,

> Current scheduler code doesn't handle SD_ASYM_PACKING in the
> find_idlest_cpu path. On few architectures, like Powerpc, cache is at a
> core. Moving threads across cores may end up in cache misses.
>
> While asym_packing can be enabled above SMT level, enabling Asym packing
> across cores could result in poorer performance due to cache misses.
> However if the initial task placement via find_idlest_cpu does take
> Asym_packing into consideration, then scheduler can avoid asym_packing
> migrations. This will result in lesser migrations and better packing and
> better overall performance.
>
> Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>

I haven't heard any comments or seen any reviews on this patch.
I have verified that it does still apply cleanly on v6.7-rc5 based
tip/master

Do let me know your thoughts on the same.

Also let me know if you want me to repost the same.

--
Thanks and Regards
Srikar Dronamraju