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Date: Fri, 2 Feb 2024 07:58:06 -0800
From: "Paul E. McKenney" <paulmck@kernel.org>
To: John Ogness <john.ogness@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>, Lai Jiangshan <jiangshanlai@gmail.com>,
	Petr Mladek <pmladek@suse.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-kernel@vger.kernel.org, rcu@vger.kernel.org
Subject: Re: [BUG] workqueues and printk not playing nice since next-20240130
Message-ID: <7b5a386e-2dcf-49f1-a8e9-c46d2a9f8800@paulmck-laptop>
Reply-To: paulmck@kernel.org
References: <410d6a87-bf34-457e-b714-1e6149d48532@paulmck-laptop>
 <87le83ara7.fsf@jogness.linutronix.de>
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On Fri, Feb 02, 2024 at 03:18:48PM +0106, John Ogness wrote:
> On 2024-02-02, "Paul E. McKenney" <paulmck@kernel.org> wrote:
> > So the system really did boot and is running just fine.  It is just that
> > there is no console output.  Details, details!
> >
> > Is there anything I can do to some combination of workqueues and printk
> > to help debug this?
> 
> The printk ringbuffer contents would certainly be interesting.
> 
> If you build the GDB scripts (CONFIG_GDB_SCRIPTS) then you will have:
> 
> (gdb) lx-dmesg

This says no such command even though I do have CONFIG_GDB_SCRIPTS=y
in my .config.

> As an alternative, you could copy the contents of
> Documentation/admin-guide/kdump/gdbmacros.txt into your .gdbinit and
> then will have:
> 
> (gdb) dmesg

This one hangs.

> There may be some hints in the kernel log as to why there is no console
> output.

On the other hand, next-20240202 doesn't show the problem.  No idea
what might have changed.  :-/

							Thanx, Paul