From: Naresh Kamboju <naresh.kamboju@linaro.org>
To: sched-ext@lists.linux.dev,
open list <linux-kernel@vger.kernel.org>,
lkft-triage@lists.linaro.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
Tejun Heo <tj@kernel.org>,
void@manifault.com, arighi@nvidia.com, changwoo@igalia.com
Subject: Boot regression: arm64: WARNING: kernel/sched/core.c:10851 at sched_change_end
Date: Tue, 16 Dec 2025 17:09:52 +0530 [thread overview]
Message-ID: <CA+G9fYuphjUO2x6qP2qPBFGSYz2WPp8fdGdiNGtyd1PmEVJrmQ@mail.gmail.com> (raw)
The following boot warning is noticed on qemu-arm64 devices booting
Linux next-20251215 on wards.
Regression Analysis:
- New regression? yes
- Reproducibility? yes
First seen on next-20251215
Bad: next-20251215 and next-20251216
Good: next-20251212
Boot regression: arm64: WARNING: kernel/sched/core.c:10851 at sched_change_end
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
$ git blame -L 10842 kernel/sched/core.c
5d1f0b2f278eb (Peter Zijlstra 2025-12-10 09:06:50 +0100 10842) ---->
if (ctx->running && sched_class_above(p->sched_class,
ctx->class)) {
5d1f0b2f278eb (Peter Zijlstra 2025-12-10 09:06:50 +0100 10843)
rq->next_class->wakeup_preempt(rq, p, 0);
5d1f0b2f278eb (Peter Zijlstra 2025-12-10 09:06:50 +0100 10844)
rq->next_class = p->sched_class;
5d1f0b2f278eb (Peter Zijlstra 2025-12-10 09:06:50 +0100 10845) }
5d1f0b2f278eb (Peter Zijlstra 2025-12-10 09:06:50 +0100 10846)
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10847) /*
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10848)
* If this was a degradation in class someone should have set
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10849)
* need_resched by now.
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10850) */
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10851) ---->
WARN_ON_ONCE(sched_class_above(ctx->class, p->sched_class) &&
47efe2ddccb1f (Peter Zijlstra 2025-10-30 12:56:34 +0100 10852)
!test_tsk_need_resched(p));
6455ad5346c9c (Peter Zijlstra 2024-11-01 14:16:10 +0100 10853) } else {
6455ad5346c9c (Peter Zijlstra 2024-11-01 14:16:10 +0100 10854)
p->sched_class->prio_changed(rq, p, ctx->prio);
6455ad5346c9c (Peter Zijlstra 2024-11-01 14:16:10 +0100 10855) }
f0e1a0643a59b (Tejun Heo 2024-06-18 10:09:17 -1000 10856) }
## Boot log
[ 0.000000] Linux version 6.19.0-rc1-next-20251215
(tuxmake@tuxmake) (aarch64-linux-gnu-gcc (Debian 13.3.0-16) 13.3.0,
GNU ld (GNU Binutils for Debian) 2.44) #1 SMP PREEMPT @1765798467
...
[ 14.659447] mlx5_core 0000:01:00.1 enp1s0f1np1: renamed from eth1
[ 14.691267] CPPC Cpufreq:FIE not enabled on systems with registers in PCC
** replaying previous printk message **
[ 14.691267] CPPC Cpufreq:FIE not enabled on systems with registers in PCC
[ 14.694920] mlx5_core 0000:01:00.0 enp1s0f0np0: renamed from eth0 (while UP)
[ 14.696414] ------------[ cut here ]------------
[ 14.696418] WARNING: kernel/sched/core.c:10851 at
sched_change_end+0x168/0x188, CPU#12: ktimers/12/117
[ 14.729321] Modules linked in: cppc_cpufreq(+) arm_dsu_pmu(+) fuse
drm backlight
[ 14.736718] CPU: 12 UID: 0 PID: 117 Comm: ktimers/12 Not tainted
6.19.0-rc1-next-20251216 #1 PREEMPT_RT
[ 14.746190] Hardware name: WIWYNN Mt.Jade Server System
B81.030Z1.0010/Mt.Jade Motherboard, BIOS 2.10.20250506-1P (SCP:
2.10.20250506) 2025/05/06
[ 14.759217] pstate: 804000c9 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 14.766169] pc : sched_change_end (kernel/sched/core.c:10851
(discriminator 7))
[ 14.770519] lr : sched_change_end (kernel/sched/core.c:10842
(discriminator 1))
[ 14.774781] sp : ffff800080d33b90
[ 14.778084] x29: ffff800080d33b90 x28: ffff07ff822f5500 x27: ffff80008e0c3660
[ 14.785213] x26: 00000000000000f0 x25: ffff07ff822f5500 x24: 0000000000000000
[ 14.792342] x23: 00000000ffffffff x22: ffffb4099c0d64d0 x21: ffff07ff822f5500
[ 14.799469] x20: ffff083e5eeaf140 x19: ffff083e5ee9b290 x18: 0000000000000000
[ 14.806597] x17: 0000000000000000 x16: ffffb4099a40ee68 x15: 0000000000000000
[ 14.813725] x14: 0000000000000000 x13: 0000000000000000 x12: 0000020000000000
[ 14.820853] x11: 00000000000000c0 x10: 0000000000000c60 x9 : ffffb40999b8d640
[ 14.827981] x8 : 000000000000000c x7 : ffff07ff92ad8400 x6 : 00000000ffffffff
[ 14.835109] x5 : 00000000000000ee x4 : 000000036b338800 x3 : 000000036b33b800
[ 14.842238] x2 : 0000000000000001 x1 : ffffb4099c0d63d8 x0 : 0000000000000010
[ 14.849366] Call trace:
[ 14.851802] sched_change_end (kernel/sched/core.c:10851
(discriminator 7)) (P)
[ 14.856153] rt_mutex_setprio (kernel/sched/sched.h:1813
kernel/sched/core.c:7368)
[ 14.860157] rt_mutex_slowunlock (kernel/locking/rtmutex.c:1341
kernel/locking/rtmutex.c:1466)
[ 14.864422] rt_spin_unlock (kernel/locking/spinlock_rt.c:86)
[ 14.868165] __hrtimer_run_queues (include/linux/spinlock_rt.h:44
kernel/time/hrtimer.c:1398 kernel/time/hrtimer.c:1843)
[ 14.872513] hrtimer_run_softirq (kernel/time/hrtimer.c:579
kernel/time/hrtimer.c:1193 kernel/time/hrtimer.c:1861)
[ 14.876600] handle_softirqs.isra.0
(arch/arm64/include/asm/jump_label.h:36 include/trace/events/irq.h:142
kernel/softirq.c:627)
[ 14.881125] run_ktimerd (kernel/softirq.c:325 kernel/softirq.c:1144)
[ 14.884520] smpboot_thread_fn (kernel/smpboot.c:160)
[ 14.888608] kthread (kernel/kthread.c:463)
[ 14.891828] ret_from_fork (arch/arm64/kernel/entry.S:861)
[ 14.895396] ---[ end trace 0000000000000000 ]---
## Source
* Kernel version: 6.19.0-rc1
* Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
* Git commit: 4a5663c04bb679631985a15efab774da58c37815
* Git Describe: next-20251215
* Test Details:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20251215
## Boot details
* Boot log: https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20251215/testrun/30561916/suite/log-parser-test/test/exception-warning-kernelschedcore-at-sched_change_end/log
* Test details:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20251215/testrun/30561916/suite/log-parser-test/test/exception-warning-kernelschedcore-at-sched_change_end/details/
* Test plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/36sbHUVfnUKPzZ4LNkOCLdiFOin
* Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/36sbH5DQckAagO0V1UEWBBkOB54/
* Kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/36sbH5DQckAagO0V1UEWBBkOB54/config
--
Linaro LKFT
https://lkft.linaro.org
next reply other threads:[~2025-12-16 11:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-16 11:39 Naresh Kamboju [this message]
2025-12-16 12:21 ` Peter Zijlstra
2025-12-16 17:23 ` Mark Rutland
2025-12-16 19:11 ` Naresh Kamboju
2025-12-17 12:04 ` Mark Rutland
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