Re: [PATCH sched_ext/for-6.13-fixes] sched_ext: Fix invalid irq restore in scx_ops_bypass()

From: Ihor Solodrai
Date: Thu Dec 19 2024 - 17:51:18 EST


On Wednesday, December 18th, 2024 at 10:34 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:

>
>
> Hello,
>
> On Tue, Dec 17, 2024 at 11:44:08PM +0000, Ihor Solodrai wrote:
>
> > I re-enabled selftests/sched_ext on BPF CI today. The kernel on CI
> > includes this patch. Sometimes there is a failure on attempt to attach
> > a dsp_local_on scheduler.
> >
> > Examples of failed jobs:
> >
> > * https://github.com/kernel-patches/bpf/actions/runs/12379720791/job/34555104994
> > * https://github.com/kernel-patches/bpf/actions/runs/12382862660/job/34564648924
> > * https://github.com/kernel-patches/bpf/actions/runs/12381361846/job/34560047798
> >
> > Here is a piece of log that is present in failed run, but not in
> > a successful run:
> >
> > 2024-12-17T19:30:12.9010943Z [ 5.285022] sched_ext: BPF scheduler "dsp_local_on" enabled
> > 2024-12-17T19:30:13.9022892Z ERR: dsp_local_on.c:37
> > 2024-12-17T19:30:13.9025841Z Expected skel->data->uei.kind == EXIT_KIND(SCX_EXIT_ERROR) (0 == 1024)
> > 2024-12-17T19:30:13.9256108Z ERR: exit.c:30
> > 2024-12-17T19:30:13.9256641Z Failed to attach scheduler
> > 2024-12-17T19:30:13.9611443Z [ 6.345087] smpboot: CPU 1 is now offline
> >
> > Could you please investigate?
>
>
> The test prog is wrong in assuming all possible CPUs to be consecutive and
> online but I'm not sure whether that's what's making the test flaky. Do you
> have dmesg from a failed run?

Tejun, can you elaborate on what you're looking for in the logs?
My understanding is that QEMU prints some of the dmesg messages.
QEMU output is available in raw logs.

Here is a link (you have to login to github to open):

https://productionresultssa1.blob.core.windows.net/actions-results/99cd995e-679f-4180-872b-d31e1f564837/workflow-job-run-7216a7c9-5129-5959-a45a-28d6f9b737e2/logs/job/job-logs.txt?rsct=text%2Fplain&se=2024-12-19T22%3A57%3A01Z&sig=z%2B%2FUtIIhli4VG%2FCCVxawBnubNwfIIsl9Q2FlTVvM8q0%3D&ske=2024-12-20T07%3A00%3A35Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2024-12-19T19%3A00%3A35Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2024-11-04&sp=r&spr=https&sr=b&st=2024-12-19T22%3A46%3A56Z&sv=2024-11-04

Generally, you can access raw logs by going to the job, and
clicking the gear on the topright -> "View raw logs".

>
> Thanks.
>
> --
> tejun