Re: Fix 80d20d35af1e ("nohz: Fix local_timer_softirq_pending()") may have revealed another problem

From: Heiner Kallweit
Date: Mon Dec 24 2018 - 16:11:23 EST


On 15.10.2018 22:58, Heiner Kallweit wrote:
> On 28.09.2018 15:18, Frederic Weisbecker wrote:
>> On Thu, Sep 27, 2018 at 06:05:46PM +0200, Thomas Gleixner wrote:
>>> On Tue, 28 Aug 2018, Frederic Weisbecker wrote:
>>>> On Fri, Aug 24, 2018 at 07:06:32PM +0200, Heiner Kallweit wrote:
>>>>> I tested it and Frederic is right, it doesn't help. Can it be somehow related to
>>>>> the cpu being brought down during suspend? Because I get the warning only during
>>>>> suspend when the cpu is inactive already (but still online).
>>>>
>>>> It's hard to tell, I haven't been able to reproduce on suspend to disk/mem.
>>>>
>>>> Does this script eventually trigger it after some time?
>>>
>>> Any update to this?
>>
>> Heiner? Can you please test the script I sent to you?
>>
>> Thanks.
>>
> Sorry, took some time .. And yes, running your script triggers the message too.
>
> [ 25.646015] x86: Booting SMP configuration:
> [ 25.646044] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.664491] smpboot: CPU 1 is now offline
> [ 25.679299] x86: Booting SMP configuration:
> [ 25.679329] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.698449] smpboot: CPU 1 is now offline
> [ 25.711698] x86: Booting SMP configuration:
> [ 25.711727] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.729185] NOHZ: local_softirq_pending 202
> [ 25.729229] NOHZ: local_softirq_pending 202
> [ 25.730759] smpboot: CPU 1 is now offline
> [ 25.744053] x86: Booting SMP configuration:
> [ 25.744083] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.762520] smpboot: CPU 1 is now offline
> [ 25.776834] x86: Booting SMP configuration:
> [ 25.776863] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.794189] NOHZ: local_softirq_pending 202
> [ 25.796672] smpboot: CPU 1 is now offline
> [ 25.805970] x86: Booting SMP configuration:
> [ 25.805999] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.827360] smpboot: CPU 1 is now offline
> [ 25.839043] x86: Booting SMP configuration:
> [ 25.839073] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.858184] NOHZ: local_softirq_pending 202
> [ 25.862182] smpboot: CPU 1 is now offline
> [ 25.873759] x86: Booting SMP configuration:
> [ 25.873789] smpboot: Booting Node 0 Processor 1 APIC 0x2
> [ 25.893385] smpboot: CPU 1 is now offline
>
Almost forgot about his topic, but the warning is still there.
Has there been any progress in analysis?