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From: Ingo Molnar <mingo@kernel.org>
To: Dave Jones <davej@redhat.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@elte.hu>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: Print out additional debugging advice when we hit lockdep BUGs
Date: Wed, 24 Apr 2013 08:48:13 +0200	[thread overview]
Message-ID: <20130424064813.GB27551@gmail.com> (raw)
In-Reply-To: <20130423163403.GA12839@redhat.com>


* Dave Jones <davej@redhat.com> wrote:

> We occasionally get reports of these BUGs being hit, and the stack trace
> doesn't necessarily always tell us what we need to know about why we are
> hitting those limits.
> 
> If users start attaching /proc/lock_stats to reports we may have more of
> a clue what's going on.

Good idea.

A detail:

>  		printk("BUG: MAX_STACK_TRACE_ENTRIES too low!\n");
>  		printk("turning off the locking correctness validator.\n");
> +		printk("Attach output of /proc/lock_stat to bug report\n");

>  		printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
>  		printk("turning off the locking correctness validator.\n");
> +		printk("Attach output of /proc/lock_stat to bug report\n");

>  		printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
>  		printk("turning off the locking correctness validator.\n");
> +		printk("Attach output of /proc/lock_stat to bug report\n");

>  		printk("BUG: MAX_LOCKDEP_CHAINS too low!\n");
>  		printk("turning off the locking correctness validator.\n");
> +		printk("Attach output of /proc/lock_stat to bug report\n");

>  		printk("BUG: MAX_LOCK_DEPTH too low, depth: %i  max: %lu!\n",
>  		       curr->lockdep_depth, MAX_LOCK_DEPTH);
>  		printk("turning off the locking correctness validator.\n");
> +		printk("Attach output of /proc/lock_stat to bug report\n");

These patterns repeated in 4 places really call for a common helper 
defined as print_lockdep_off(fmt...) or so?

(Can be a followup patch if that's easier for you.)

Thanks,

	Ingo

  reply	other threads:[~2013-04-24  6:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-23 16:34 Print out additional debugging advice when we hit lockdep BUGs Dave Jones
2013-04-24  6:48 ` Ingo Molnar [this message]
2013-04-25 17:40   ` Dave Jones
2013-04-26  6:32     ` Ingo Molnar
2013-04-26 14:19     ` [tip:core/locking] lockdep: Consolidate bug messages into a single print_lockdep_off() function tip-bot for Dave Jones
2013-04-26 14:18 ` [tip:core/locking] lockdep: Print out additional debugging advice when we hit lockdep BUGs tip-bot for Dave Jones

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