All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Tom Cook <tom.k.cook@gmail.com>,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Subject: Re: Tracers+cyclictest causing kernel oops
Date: Tue, 21 May 2013 13:16:55 +0200	[thread overview]
Message-ID: <519B57A7.1010901@linutronix.de> (raw)
In-Reply-To: <CAFSh4UwD5yyJrtKwUaOX-uiUuzVf7YaDbM4vbZ1EFZBf6F1JHg@mail.gmail.com>

please CC the list.

On 05/11/2013 06:43 PM, Tom Cook wrote:
> Okay, I've built the same kernel config but without kgdb enabled.
> Running cyclictest with a tracer enabled (-f in this case) causes the
> crash below.
> 
> I'm not big on debugging these things yet.  Since cyclictest works
> without the tracers enabled and causes a crash with them enabled, the
> problem must be in the tracers themselves, right?  Actually, 'echo
> function > current_tracer' has the same effect.
> 
> Is that trace really saying that the processor is in mode 0?  AFAICT,
> ARM does not have a mode 0 unless you truncate the mode number to four
> bits - in which case mode '0' is user mode.  The process name seems to
> be a red herring - repeating this can turn up almost any process
> running on the system, from interrupt handler threads to bash.
> 
> Is this a known problem?  Any tips on figuring it out?

Not known until you brought that up. I just booted x86 with kgdb=y and
did "echo function > current_tracer" with no side effects. I don't have
ARM at hand right now. Do you do anything kgdb related besides enabling
it in the kernel?

> 
> Thanks,
> Tom

Sebastian

  parent reply	other threads:[~2013-05-21 11:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-26  8:04 Tracers+cyclictest causing kernel oops Tom Cook
2013-04-29  7:16 ` Tom Cook
2013-05-03 16:05   ` Sebastian Andrzej Siewior
2013-05-12  5:14     ` Tom Cook
     [not found]     ` <CAFSh4UwD5yyJrtKwUaOX-uiUuzVf7YaDbM4vbZ1EFZBf6F1JHg@mail.gmail.com>
2013-05-21 11:16       ` Sebastian Andrzej Siewior [this message]
2013-05-21 15:20         ` Tom Cook
2013-05-27  8:02           ` Uwe Kleine-König
2013-05-27 21:23             ` Tom Cook
2013-05-28  6:53               ` Uwe Kleine-König
2013-06-21 11:01                 ` Tom Cook
2013-05-31  9:23           ` Sebastian Andrzej Siewior
2013-05-31  9:31             ` Tom Cook
2013-06-21 11:21             ` Tom Cook
2013-06-21 14:17               ` Tom Cook
2013-06-21 14:58                 ` Tom Cook
2013-06-21 15:00               ` Sebastian Andrzej Siewior

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=519B57A7.1010901@linutronix.de \
    --to=bigeasy@linutronix.de \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=tom.k.cook@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.