Subject: Re: [PATCH] lockdep: Show up to three levels for a deadlock scenario
To: Peter Zijlstra <peterz@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Morton <akpm@linux-foundation.org>
Newsgroups: gmane.linux.kernel
References: <20171214123852.515257aa@gandalf.local.home>
 <20171214175931.mlvr7lk7bcnsqu5i@hirez.programming.kicks-ass.net>
From: Dhaval Giani <dhaval.giani@oracle.com>
Message-ID: <3317dd1a-1a39-3295-eb90-538be296dff8@oracle.com>
Date: Tue, 19 Dec 2017 11:30:29 -0500
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On 2017-12-14 12:59 PM, Peter Zijlstra wrote:
> On Thu, Dec 14, 2017 at 12:38:52PM -0500, Steven Rostedt wrote:
>>
>> Currently, when lockdep detects a possible deadlock scenario that involves 3
>> or more levels, it just shows the chain, and a CPU sequence order of the
>> first and last part of the scenario, leaving out the middle level and this
>> can take a bit of effort to understand. By adding a third level, it becomes
>> easier to see where the deadlock is.
> 
> So is anybody actually using this? This (together with the callchain for
> #0) is always the first thing of the lockdep output I throw away.
> 

Yes :-). The other stuff is unreadable to people not you.

Dhaval