Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 15 Jun 2023 09:40:40 +0200
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     "Richard W.M. Jones" <rjones@redhat.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Aaron Thompson <dev@aaront.org>, linux-kernel@vger.kernel.org
Subject: Re: printk.time causes rare kernel boot hangs
Message-ID: <20230615074040d166068b@mail.local>
References: <20230614113536.GJ1639749@hirez.programming.kicks-ass.net>
 <20230614125320.GA1640563@hirez.programming.kicks-ass.net>
 <20230614130348.GF7636@redhat.com>
 <20230614130945.GK1639749@hirez.programming.kicks-ass.net>
 <20230614145348.GB1640563@hirez.programming.kicks-ass.net>
 <20230614150717.GG7636@redhat.com>
 <20230614151920.GN1639749@hirez.programming.kicks-ass.net>
 <20230614153108.GC1640563@hirez.programming.kicks-ass.net>
 <20230614155016.GI7636@redhat.com>
 <20230614173430.GB10301@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230614173430.GB10301@redhat.com>
Precedence: bulk

Hello,

On 14/06/2023 18:34:30+0100, Richard W.M. Jones wrote:
> 
> FWIW attached is a test program that runs the qemu instances in
> parallel (up to 8 threads), which seems to be a quicker way to hit the
> problem for me.  Even on Intel, with this test I can hit the bug in a
> few hundred iteration.
> 

I'm just chiming in to say that we do hit the same issue on the Yocto
Project CI. We are using qemu 8.0.0 on Intel hardware and a 6.1 kernel.

I see that f31dcb152a3d0816e2f1deab4e64572336da197d hasn't been
backported so it may not be the culprit. However, this seems to have
started happening when we switched from 5.15 to 6.1.

Regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com