From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH v5 3/9] x86/head: Move early exception panic code into
 early_fixup_exception
Date: Mon, 4 Apr 2016 08:36:35 -0700
Message-ID: <57028A03.3000902@linux.intel.com>
References: <cover.1459605520.git.luto@kernel.org>
 <4085070316fc3ab29538d3fcfe282648d1d4ee2e.1459605520.git.luto@kernel.org>
 <20160402183919.GA2538@pd.tnic>
 <CALCETrUJVDpzNQMsY=_jWNOMer+TdW2p4wES4OBCfYU7gq3fbg@mail.gmail.com>
 <20160402204752.GC2538@pd.tnic>
 <CALCETrXHR3T3PJwOWRFHTMK5WjhDyTJfaJtkiHd+g7evnqp54A@mail.gmail.com>
 <20160404115206.GG8372@quack.suse.cz>
 <CALCETrVriftUPNZ8pCQ1x9TWDHnRx8fWUvJgCQToPEOxqMLb3w@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	xen-devel <Xen-devel@lists.xen.org>,
	Borislav Petkov <bp@alien8.de>, X86 ML <x86@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Petr Mladek <pmladek@suse.cz>, KVM list <kvm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@amacapital.net>, Jan Kara <jack@suse.cz>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <CALCETrVriftUPNZ8pCQ1x9TWDHnRx8fWUvJgCQToPEOxqMLb3w@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

On 4/4/2016 8:32 AM, Andy Lutomirski wrote:
>
> Adding locking would be easy enough, wouldn't it?
>
> But do any platforms really boot a second CPU before switching to real
> printk?  Given that I see all the smpboot stuff in dmesg, I guess real
> printk happens first.  I admit I haven't actually checked.

adding locking also makes things more fragile in terms of getting the last thing out
before you go down in flaming death....

until it's a proven problem, this early, get the message out at all is more important
than getting it out perfectly, sometimes.