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From: Ingo Molnar <mingo@elte.hu>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Frédéric Weisbecker" <fweisbec@gmail.com>,
	"Steven Rostedt" <rostedt@goodmis.org>,
	"Linus Torvalds" <torvalds@linux-foundation.org>,
	"Maciej Rutecki" <maciej.rutecki@gmail.com>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Thomas Gleixner" <tglx@linutronix.de>
Subject: Re: [Linux 2.6.29-rc2] BUG: using smp_processor_id() in preemptible
Date: Tue, 27 Jan 2009 16:49:46 +0100	[thread overview]
Message-ID: <20090127154946.GA28209@elte.hu> (raw)
In-Reply-To: <200901271628.54037.rjw@sisk.pl>


* Rafael J. Wysocki <rjw@sisk.pl> wrote:

> > In fact whatever check you put in it's _always_ going to be 
> > fundamentally more fragile than direct instrumentation: you cannot 
> > possibly check all possible places that enable interrupts. (they could 
> > be disabling interrupts as a _restore_irqs() sequence for example)
> 
> In this particular case, I'm not really interested in that.  What I'm 
> interested in is which driver's ->suspend_late() or ->resume_early() (or 
> the equivalents for sysdevs) has enabled interrupts, which is quite easy 
> to check directly.

But this is exactly what it does - without any need for debug checks 
spread around!

You'll get a _full stack dump_ from the very driver that is enabling 
interrupts! You dont get a trace - you get a stack dump of the very place 
that is buggy. It does not get any better than that.

	Ingo

  reply	other threads:[~2009-01-27 15:50 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-17  8:58 [Linux 2.6.29-rc2] BUG: using smp_processor_id() in preemptible Maciej Rutecki
2009-01-25  2:37 ` Andrew Morton
2009-01-25 11:57   ` Thomas Gleixner
2009-01-25 14:19   ` Maciej Rutecki
2009-01-25 16:30   ` Maciej Rutecki
2009-01-26 16:07 ` Linus Torvalds
2009-01-26 16:53   ` Rafael J. Wysocki
2009-01-26 17:41     ` Ingo Molnar
2009-01-26 19:21       ` Rafael J. Wysocki
2009-01-26 20:35         ` Ingo Molnar
2009-01-26 20:48           ` Rafael J. Wysocki
2009-01-26 21:35             ` Ingo Molnar
2009-01-27 15:28               ` Rafael J. Wysocki
2009-01-27 15:49                 ` Ingo Molnar [this message]
2009-01-27 21:18                   ` Rafael J. Wysocki
2009-01-29 15:07                     ` Ingo Molnar
2009-01-29 22:29                       ` Rafael J. Wysocki
2009-01-30 14:06                         ` Ingo Molnar
2009-01-30 21:30                           ` Rafael J. Wysocki

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