Re: Very high scheduling delay with plenty of idle CPUs

[Peter Zijlstra]

On Thu, Nov 07, 2024 at 11:28:07PM -0800, Saravana Kannan wrote:
> Hi scheduler folks,
> 
> I'm running into some weird scheduling issues when testing non-sched
> changes on a Pixel 6 that's running close to 6.12-rc5. I'm not sure if
> this is an issue in earlier kernel versions or not.
> 

It's a bit unfortunate you don't have a known good kernel there. Anyway,
one thing that recently came up is that DELAY_DEQUEUE can cause some
delays, specifically it can inhibit wakeup migration.

You can either test with that feature turned off, or apply something
like the following patch:

  https://lkml.kernel.org/r/20241106135346.GL24862@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx