* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> As suggested by Thomas Gleixner, the second patch now integrates
> a fix in case the sanity check fails and the clockevent isn't programmed
> as expected.
> 
> Frederic Weisbecker (2):
>   nohz: Fix again collision between tick and other hrtimers
>   tick: Make sure tick timer is active when bypassing reprogramming
> 
>  kernel/time/tick-sched.c | 33 ++++++++++++++++++++++++++++++---
>  kernel/time/tick-sched.h |  2 ++
>  2 files changed, 32 insertions(+), 3 deletions(-)

So I think one of these is causing a new warning on latest -tip:

[  333.341756] ------------[ cut here ]------------
[  333.346404] WARNING: CPU: 0 PID: 0 at kernel/time/tick-sched.c:874 __tick_nohz_idle_enter+0x461/0x490
[  333.355614] Modules linked in:
[  333.358679] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc7-00955-g76f8909-dirty #1
[  333.366761] Hardware name: Supermicro H8DG6/H8DGi/H8DG6/H8DGi, BIOS 2.0b       03/01/2012
[  333.374935] task: ffffffff81e0e4c0 task.stack: ffffffff81e00000
[  333.380859] RIP: 0010:__tick_nohz_idle_enter+0x461/0x490
[  333.386167] RSP: 0018:ffff880417c03f38 EFLAGS: 00010093
[  333.391395] RAX: 0000004d99348555 RBX: 0000004d7a84b800 RCX: 0000000000000001
[  333.398527] RDX: 7fffffffffffffff RSI: 0000000000000001 RDI: 0000004d7a84b800
[  333.405659] RBP: ffff880417c03f90 R08: 000000000004fdfe R09: 0000000000000000
[  333.412792] R10: ffffffffffffff0a R11: 00000001000082f8 R12: 0000004d9934d4df
[  333.419926] R13: 0000000000000000 R14: ffff880417c0c740 R15: ffff880417c14880
[  333.427060] FS:  0000000000000000(0000) GS:ffff880417c00000(0000) knlGS:0000000000000000
[  333.435145] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  333.440892] CR2: 00007fbb1024b010 CR3: 000000081451a000 CR4: 00000000000406f0
[  333.448024] Call Trace:
[  333.450477]  <IRQ>
[  333.452510]  tick_nohz_irq_exit+0x25/0x30
[  333.456523]  irq_exit+0xa4/0xc0
[  333.459667]  do_IRQ+0x4f/0xd0
[  333.462638]  common_interrupt+0x90/0x90
[  333.466478] RIP: 0010:acpi_idle_do_entry+0x31/0x40
[  333.471296] RSP: 0018:ffffffff81e03d90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffc1
[  333.478862] RAX: 0000000000080000 RBX: ffff880c163b1000 RCX: 000000000000001f
[  333.485995] RDX: 4ec4ec4ec4ec4ec5 RSI: 0000000000000034 RDI: ffff880c163b1064
[  333.493128] RBP: ffffffff81e03dd8 R08: ffff880417c18324 R09: 0000000000000008
[  333.500260] R10: ffffffff81e03dc8 R11: 0000000000000002 R12: ffff880c163b1064
[  333.507386] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001
[  333.514519]  </IRQ>
[  333.516630]  ? acpi_idle_enter+0x10c/0x2c0
[  333.520728]  cpuidle_enter_state+0xfa/0x2a0
[  333.524911]  cpuidle_enter+0x17/0x20
[  333.528494]  call_cpuidle+0x23/0x40
[  333.532001]  do_idle+0x174/0x1b0
[  333.535236]  cpu_startup_entry+0x71/0x80
[  333.539161]  rest_init+0x77/0x80
[  333.542394]  start_kernel+0x429/0x44a
[  333.546061]  x86_64_start_reservations+0x2a/0x2c
[  333.550706]  x86_64_start_kernel+0x168/0x176
[  333.554980]  secondary_startup_64+0x9f/0x9f
[  333.559163] Code: fd ff ff b9 02 00 00 00 31 d2 48 89 de 4c 89 ff e8 e5 0a ff ff 49 8b 46 18 e9 72 fe ff ff 49 8b 46 18 48 39 c3 0f 8d 65 fe ff ff <0f> ff e9 2b fe ff ff 41 83 7f 48 02 0f 85 4f fe ff ff 4c 89 ff 
[  333.578100] ---[ end trace 782ee3b70f3c99e1 ]---

I saw this warning on Intel and AMD systems as well.

Config attached.

Thanks,

	Ingo