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Date: Mon, 06 Nov 2017 11:39:41 +0100
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From: Takashi Iwai <tiwai@suse.de>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Dmitry Vyukov <dvyukov@google.com>,
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Subject: Re: [alsa-devel] BUG: soft lockup
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On Thu, 02 Nov 2017 10:09:51 +0100,
Kirill A. Shutemov wrote:
> 
> On Thu, Nov 02, 2017 at 09:23:58AM +0100, Takashi Iwai wrote:
> > 
> > Currently the least ALSA timer interrupt period is limited to 1ms.
> > Does it still too much?
> > 
> > Can the reproducer triggers it reliably?  If yes, could you forward
> > it, too (and config as well), so that I'll try to dig down more exact
> > code paths?
> 
> All of that is part of original report:
> 
> http://lkml.kernel.org/r/94eb2c19df188b1926055cf13c21@google.com
> 
> marc.info hasn't stored repro.c for some reasone. Attached.
> 
> I've just check it reproduces reliably for me in KVM.
> 
> I also checked that it's not specific to THP -- still trigirable with huge
> pages disabled.

I guess this is the same issue Jerome forwarded recently, and it was
fixed by limiting the amount of ALSA timer instances.  I queued the
fix in sound git tree for-linus branch, commit
9b7d869ee5a77ed4a462372bb89af622e705bfb8
    ALSA: timer: Limit max instances per timer

It'll be likely included in 4.14 final.


thanks,

Takashi