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 S934983AbcIUTJE (ORCPT <rfc822;w@1wt.eu>);
        Wed, 21 Sep 2016 15:09:04 -0400
Received: from mail-pf0-f171.google.com ([209.85.192.171]:35779 "EHLO
        mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1752263AbcIUTJD (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 21 Sep 2016 15:09:03 -0400
Date: Wed, 21 Sep 2016 20:08:56 +0100
From: Matt Fleming <matt@codeblueprint.co.uk>
To: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Byungchul Park <byungchul.park@lge.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Luca Abeni <luca.abeni@unitn.it>, Rik van Riel <riel@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Wanpeng Li <wanpeng.li@hotmail.com>, Yuyang Du <yuyang.du@intel.com>,
        Jan Kara <jack@suse.cz>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        linux-kernel@vger.kernel.org, Mel Gorman <mgorman@techsingularity.net>,
        Mike Galbraith <umgwanakikbuti@gmail.com>
Subject: Re: [PATCH v2 7/7] sched/core: Add debug code to catch missing
 update_rq_clock()
Message-ID: <20160921190856.GP2892@codeblueprint.co.uk>
References: <20160921133813.31976-1-matt@codeblueprint.co.uk>
 <20160921133813.31976-8-matt@codeblueprint.co.uk>
 <20160921155826.GB8408@pathway.suse.cz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20160921155826.GB8408@pathway.suse.cz>
User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 21 Sep, at 05:58:27PM, Petr Mladek wrote:
> 
> I am not sure how the above call chain is realistic. But adding
> WARN_ON() into the scheduler paths is risky in general.

It's not clear to me why this should be the case. WARN_ON() calls have
existed in the scheduler paths since forever.

If the new async printk patches make that impossible then surely they
need fixing, not the scheduler?