Re: [PATCH 10/24] sched/uclamg: Handle delayed dequeue

From: Dietmar Eggemann
Date: Wed Sep 11 2024 - 07:50:22 EST


On 11/09/2024 11:13, Peter Zijlstra wrote:
> On Wed, Sep 11, 2024 at 11:10:26AM +0200, Mike Galbraith wrote:
>> On Wed, 2024-09-11 at 10:45 +0200, Peter Zijlstra wrote:
>>> On Wed, Sep 11, 2024 at 09:35:16AM +0100, Luis Machado wrote:

[...]

>>>> So probably an unexpected decrement or lack of an increment somewhere.
>>>
>>> Yeah, that's buggered. Ok, I'll go rebase sched/core and take this patch
>>> out. I'll see if I can reproduce that.
>>
>> Hm, would be interesting to know how the heck he's triggering that.
>>
>> My x86_64 box refuses to produce any such artifacts with anything I've
>> tossed at it, including full LTP with enterprise RT and !RT configs,
>> both in master and my local SLE15-SP7 branch. Hohum.
>
> Yeah, my hackbench runs also didn't show that. Perhaps something funny
> with cgroups. I didn't test cgroup bandwidth for exanple.

Don't see it either on my Arm64 Juno-r0 (6 CPUs) with:

cgexec -g cpu:/A/B/C hackbench -l 1000

We are checking the Pixel6 now.