linux-kernel - Re: printk.time causes rare kernel boot hangs

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Message-ID: <20230614130348.GF7636@redhat.com>
Date:   Wed, 14 Jun 2023 14:03:48 +0100
From:   "Richard W.M. Jones" <rjones@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Aaron Thompson <dev@...ont.org>, linux-kernel@...r.kernel.org
Subject: Re: printk.time causes rare kernel boot hangs

On Wed, Jun 14, 2023 at 02:53:20PM +0200, Peter Zijlstra wrote:
> Ooooh, what qemu version do you have? There were some really dodgy
> reports all around self modifying code, all reported on 7.2, that seems
> to have gone away with 8.

> Now, all of them were using TCG, and I think you're using KVM.

I'm using qemu-system-x86-8.0.0-4.fc39.x86_64 with KVM.  The host
kernel is 6.4.0-0.rc5.41.fc39.x86_64.

> I've at least 36000 cycles and still nothing :-(, let me go try your
> .config.

I can definitely reproduce this with your config (but AMD host), so
that's odd.  Let me try with Intel hardware and your config.  You
really should see this with only a few thousands iterations.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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