linux-kernel - Re: Long standing kernel warning: perfevents: irq loop stuck!

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Date:   Mon, 26 Feb 2018 12:32:44 -0800
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Andi Kleen <ak@...ux.intel.com>,
        "Liang, Kan" <kan.liang@...el.com>, jolsa@...hat.com,
        bigeasy@...utronix.de, "H. Peter Anvin" <hpa@...or.com>,
        Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: Long standing kernel warning: perfevents: irq loop stuck!

On Fri, Feb 23, 2018 at 4:14 AM, Peter Zijlstra <peterz@...radead.org> wrote:
> On Thu, Feb 22, 2018 at 08:59:47PM -0800, Cong Wang wrote:
>> Hello,
>>
>> We keep seeing the following kernel warning from 3.10 kernel to 4.9
>> kernel, it exists for a rather long time.
>>
>> Google search shows there was a patch from Ingo:
>> https://patchwork.kernel.org/patch/6308681/
>>
>> but it doesn't look like ever merged into mainline...
>>
>> I don't know how it is triggered. Please let me know if any other
>> information I can provide.
>
> What exact workload are you using to reproduce?

I have no idea how to reproduce it. It has been reported so many times
from so many different machines via ABRT.

>
> And I'm taking that the patch 'works' for you?

I don't try it yet, because according to Ingo himself, that patch
is not complete:

"
Also, I'd apply the quirk not just to Haswell, but Nehalem, Westmere
and Ivy Bridge as well, I have seen it as early as on a Nehalem
prototype box.
"

I can try it if that patch makes sense for you and if you can make it
complete. ;)

>
> Given the HSD143 errata and its possible relevance, have you tried
> changing the magic number to 32, does it then still fix things?
>
> No real objection to the patch as such, it just needs a coherent comment
> and a tested-by tag I think.

I will give it a try. Please let me know if you have an updated
version of that patch I can apply on recent kernel (4.9), since it was
made almost 3 years ago, otherwise I can apply it manually.

It will take some time due to the deployment process of a new kernel.

Thanks!