From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>, Derek Barbosa <debarbos@redhat.com>
Cc: pmaldek@suse.com, williams@redhat.com, tglx@linutronix.de,
linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: test 1: was: Re: A Comparison of printk between upstream and linux-rt-devel
Date: Mon, 26 Aug 2024 19:02:49 +0206 [thread overview]
Message-ID: <871q2b8bou.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <Zsyafduo2UItzLAK@pathway.suse.cz>
On 2024-08-26, Petr Mladek <pmladek@suse.com> wrote:
>> [ 111.777491] ? __pfx_hrtimer_wakeup+0x10/0x10
>> ** 8555 printk messages dropped **
>> [ 111.807996] ? __lruvec_stat_mod_folio+0x86/0xd0
>>
>
> I see. I guess that the panic CPU ended in a deadlock in
> console_flush_on_panic() after it ignored the console_lock().
> Otherwise, it would have flushed the last messages and rebooted.
For the 8250, I would expect the legacy driver (even during "hope and
pray" mode) to be fairly reliable.
If this is running in QEMU, you could attach gdb and dump the backtrace
for the panic CPU and investigate some state variables. If this is
reproducible, it may be worth investigating where/why the legacy
printing is choking.
John Ogness
next prev parent reply other threads:[~2024-08-26 16:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-22 16:32 A Comparison of printk between upstream and linux-rt-devel Derek Barbosa
2024-08-23 7:09 ` Sebastian Andrzej Siewior
2024-08-23 18:45 ` Derek Barbosa
2024-08-23 7:11 ` Sebastian Andrzej Siewior
2024-08-23 10:19 ` test 1: was: " Petr Mladek
2024-08-23 19:06 ` Derek Barbosa
2024-08-26 14:02 ` Petr Mladek
2024-08-26 14:46 ` Derek Barbosa
2024-08-26 15:08 ` Petr Mladek
2024-08-26 16:56 ` John Ogness [this message]
2024-08-26 17:05 ` Derek Barbosa
2024-08-26 18:00 ` John Ogness
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