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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 $ 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