realtime ubuntu pro kernel unstable

[guprobr]

I'm investigating why with linux-image-6.8.1-1009-realtime kernel my WakkaQt program leads the whole system unstable.

At this point its difficult to understand if the problem is with ubuntu realtime generic kernel, QT6-multimedia, gStreamer or the program itself.

[guprobr]

2024-09-17T20:46:35.602059-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [CRTC:167:pipe B] flip_done timed out 2024-09-17T20:46:35.602078-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [CRTC:98:pipe A] flip_done timed out 2024-09-17T20:46:45.372035-03:00 hexaveggie kernel: Fence expiration time out i915-0000:00:02.0:multiqueue3:src[3446]:584!

2024-09-17T20:48:10.444066-03:00 hexaveggie kernel: rcu: INFO: rcu_preempt self-detected stall on CPU 2024-09-17T20:48:10.444078-03:00 hexaveggie kernel: rcu: 0-....: (60027 ticks this GP) idle=889c/1/0x4000000000000000 softirq=0/0 fqs=14396 rcuc=60022 jiffies(starved) 2024-09-17T20:48:10.444079-03:00 hexaveggie kernel: rcu: hardirqs softirqs csw/system 2024-09-17T20:48:10.444079-03:00 hexaveggie kernel: rcu: number: 8 0 16 2024-09-17T20:48:10.444080-03:00 hexaveggie kernel: rcu: cputime: 68 29932 0 ==> 29999(ms) 2024-09-17T20:48:10.444081-03:00 hexaveggie kernel: rcu: (t=60000 jiffies g=39697 q=33168 ncpus=8) 2024-09-17T20:48:10.444081-03:00 hexaveggie kernel: CPU: 0 PID: 618 Comm: irq/172-i915 Not tainted 6.8.1-1009-realtime #9-Ubuntu 2024-09-17T20:48:10.444089-03:00 hexaveggie kernel: Hardware name: Dell Inc. Inspiron 15 3511/0D73T7, BIOS 1.29.0 04/25/2024 2024-09-17T20:48:10.444090-03:00 hexaveggie kernel: RIP: 0010:intel_context_remove_breadcrumbs+0xed/0x1b0 [i915] 2024-09-17T20:48:10.444090-03:00 hexaveggie kernel: Code: 00 4c 89 f3 48 2d 88 00 00 00 49 39 d7 75 87 49 8b 45 40 49 39 c7 74 3a 48 8b 7d d0 e8 0c fc d4 dc eb 02 f3 90 41 8b 44 24 40 <85> c0 75 f5 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 2024-09-17T20:48:10.444091-03:00 hexaveggie kernel: RSP: 0018:ffffa5b98935bca0 EFLAGS: 00000202 2024-09-17T20:48:10.444091-03:00 hexaveggie kernel: RAX: 0000000000000001 RBX: ffff936ecdf72308 RCX: 0000000000000000 2024-09-17T20:48:10.444092-03:00 hexaveggie kernel: RDX: ffffffffc0cd2910 RSI: 0000000000000000 RDI: 0000000000000000 2024-09-17T20:48:10.444092-03:00 hexaveggie kernel: RBP: ffffa5b98935bcd0 R08: 0000000000000000 R09: 0000000000000000 2024-09-17T20:48:10.444092-03:00 hexaveggie kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffff936ecdf72300 2024-09-17T20:48:10.444093-03:00 hexaveggie kernel: R13: ffff936ec93b5590 R14: ffff936ec93b5548 R15: ffff936ec93b55d0 2024-09-17T20:48:10.444093-03:00 hexaveggie kernel: FS: 0000000000000000(0000) GS:ffff93723f400000(0000) knlGS:0000000000000000 2024-09-17T20:48:10.444094-03:00 hexaveggie kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 2024-09-17T20:48:10.444094-03:00 hexaveggie kernel: CR2: 00007cd1d8e1e000 CR3: 0000000423046002 CR4: 0000000000f70ef0 2024-09-17T20:48:10.444094-03:00 hexaveggie kernel: PKRU: 55555554 2024-09-17T20:48:10.444095-03:00 hexaveggie kernel: Call Trace: 2024-09-17T20:48:10.444095-03:00 hexaveggie kernel: 2024-09-17T20:48:10.444096-03:00 hexaveggie kernel: ? show_regs+0x6d/0x80 2024-09-17T20:48:10.444096-03:00 hexaveggie kernel: ? dump_cpu_task+0x77/0x90 2024-09-17T20:48:10.444096-03:00 hexaveggie kernel: ? rcu_dump_cpu_stacks+0xe8/0x180 2024-09-17T20:48:10.444097-03:00 hexaveggie kernel: ? print_cpu_stall+0x136/0x2d0 2024-09-17T20:48:10.444097-03:00 hexaveggie kernel: ? check_cpu_stall+0x13c/0x230 2024-09-17T20:48:10.444097-03:00 hexaveggie kernel: ? rcu_pending+0x32/0x1f0 2024-09-17T20:48:10.444098-03:00 hexaveggie kernel: ? rcu_sched_clock_irq+0xd5/0x3c0 2024-09-17T20:48:10.444098-03:00 hexaveggie kernel: ? update_process_times+0x71/0xb0 2024-09-17T20:48:10.444099-03:00 hexaveggie kernel: ? tick_sched_handle+0x28/0x70 2024-09-17T20:48:10.444099-03:00 hexaveggie kernel: ? tick_nohz_highres_handler+0x78/0xa0 2024-09-17T20:48:10.444099-03:00 hexaveggie kernel: ? pfx_tick_nohz_highres_handler+0x10/0x10 2024-09-17T20:48:10.444099-03:00 hexaveggie kernel: ? hrtimer_run_queues+0x128/0x2e0 2024-09-17T20:48:10.444100-03:00 hexaveggie kernel: ? hrtimer_interrupt+0xf1/0x240 2024-09-17T20:48:10.444100-03:00 hexaveggie kernel: ? sysvec_apic_timer_interrupt+0x4e/0x150 2024-09-17T20:48:10.444101-03:00 hexaveggie kernel: ? sysvec_apic_timer_interrupt+0x8d/0xd0 2024-09-17T20:48:10.444101-03:00 hexaveggie kernel: 2024-09-17T20:48:10.444101-03:00 hexaveggie kernel: 2024-09-17T20:48:10.444102-03:00 hexaveggie kernel: ? asm_sysvec_apic_timer_interrupt+0x1b/0x20 2024-09-17T20:48:10.444102-03:00 hexaveggie kernel: ? pfx_virtual_context_destroy+0x10/0x10 [i915] 2024-09-17T20:48:10.444102-03:00 hexaveggie kernel: ? intel_context_remove_breadcrumbs+0xed/0x1b0 [i915] 2024-09-17T20:48:10.444103-03:00 hexaveggie kernel: execlists_schedule_out+0xe4/0x250 [i915] 2024-09-17T20:48:10.444103-03:00 hexaveggie kernel: execlists_submission_tasklet+0xe8/0x300 [i915] 2024-09-17T20:48:10.444104-03:00 hexaveggie kernel: tasklet_action_common.isra.0+0x12d/0x240 2024-09-17T20:48:10.444104-03:00 hexaveggie kernel: tasklet_hi_action+0x1f/0x30 2024-09-17T20:48:10.444104-03:00 hexaveggie kernel: handle_softirqs.isra.0+0xeb/0x320 2024-09-17T20:48:10.444105-03:00 hexaveggie kernel: ? pfx_irq_forced_thread_fn+0x10/0x10 2024-09-17T20:48:10.444105-03:00 hexaveggie kernel: local_bh_enable_ip+0x86/0xd0 2024-09-17T20:48:10.444105-03:00 hexaveggie kernel: irq_forced_thread_fn+0x73/0x90 2024-09-17T20:48:10.444106-03:00 hexaveggie kernel: irq_thread+0xfa/0x1b0 2024-09-17T20:48:10.444106-03:00 hexaveggie kernel: ? preempt_count_sub+0x52/0x80 2024-09-17T20:48:10.444106-03:00 hexaveggie kernel: ? pfx_irq_thread_dtor+0x10/0x10 2024-09-17T20:48:10.444107-03:00 hexaveggie kernel: ? pfx_irq_thread+0x10/0x10 2024-09-17T20:48:10.444107-03:00 hexaveggie kernel: kthread+0xfe/0x130 2024-09-17T20:48:10.444108-03:00 hexaveggie kernel: ? pfx_kthread+0x10/0x10 2024-09-17T20:48:10.444108-03:00 hexaveggie kernel: ret_from_fork+0x44/0x70 2024-09-17T20:48:10.444108-03:00 hexaveggie kernel: ? __pfx_kthread+0x10/0x10 2024-09-17T20:48:10.444109-03:00 hexaveggie kernel: ret_from_fork_asm+0x1b/0x30 2024-09-17T20:48:10.444109-03:00 hexaveggie kernel: 2024-09-17T20:48:26.194033-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR flip_done timed out 2024-09-17T20:48:26.194048-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [CRTC:167:pipe B] commit wait timed out 2024-09-17T20:48:32.446065-03:00 hexaveggie kernel: sysrq: HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e) memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystems(j) sak(k) show-backtrace-all-active-cpus(l) show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p) show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u) force-fb(v) show-blocked-tasks(w) dump-ftrace-buffer(z) 2024-09-17T20:48:34.790035-03:00 hexaveggie kernel: message repeated 16 times: [ sysrq: HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e) memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystems(j) sak(k) show-backtrace-all-active-cpus(l) show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p) show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u) force-fb(v) show-blocked-tasks(w) dump-ftrace-buffer(z) ] 2024-09-17T20:48:36.434017-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR flip_done timed out 2024-09-17T20:48:36.434035-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [CRTC:98:pipe A] commit wait timed out 2024-09-17T20:48:46.674059-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR flip_done timed out 2024-09-17T20:48:46.674072-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [PLANE:31:plane 1A] commit wait timed out 2024-09-17T20:48:56.914023-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR flip_done timed out 2024-09-17T20:48:56.914037-03:00 hexaveggie kernel: i915 0000:00:02.0: [drm] ERROR [PLANE:100:plane 1B] commit wait timed out

[guprobr]

seems to be something starting at a couple kernel versions and i915 intel driver

"i'm having costant freezes since 6.8 while watching videos on youtube. Rolled back on 6.6.10 and it works like a charm. Running Pop Os - Wayland on a thinkpad"

https://www.reddit.com/r/linuxquestions/comments/1dflaug/i915_drivers_constantly_freezing_up_computer_as/

[guprobr]

tried with 6.8.0-45-lowlatency #45.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Sep 3 09:30:47 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

no problem at all.

So far, this bug only happens with ubuntu pro realtime kernel linux-image-6.8.1-1009-realtime