From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1755749AbdJLJer (ORCPT <rfc822;w@1wt.eu>);
        Thu, 12 Oct 2017 05:34:47 -0400
Received: from mx2.suse.de ([195.135.220.15]:45835 "EHLO mx2.suse.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1755124AbdJLJep (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 12 Oct 2017 05:34:45 -0400
Date: Thu, 12 Oct 2017 11:34:42 +0200
From: Petr Mladek <pmladek@suse.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [PATCH] printk: Remove superfluous memory barriers from
 printk_safe
Message-ID: <20171012093442.GC2882@pathway.suse.cz>
References: <20171011124647.7781f98f@gandalf.local.home>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20171011124647.7781f98f@gandalf.local.home>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed 2017-10-11 12:46:47, Steven Rostedt wrote:
> From: Steven Rostedt (VMware) <rostedt@goodmis.org>
> 
> The variable printk_safe_irq_ready is set and never cleared at system
> boot up, when there's only one CPU active. It is set before other
> CPUs come on line. Also, it is extremely unlikely that an NMI would
> trigger this early in boot up (which I wonder why we even have this
> variable at all).
> 
> Also mark the printk_safe_irq_ready as read mostly, as it is set at
> system boot up, and never touched again.
> 
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Great catch! It makes perfect sense:

Reviewed-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr