From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Tom Cook <tom.k.cook@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-rt-users <linux-rt-users@vger.kernel.org>
Subject: Re: Tracers+cyclictest causing kernel oops
Date: Mon, 27 May 2013 10:02:48 +0200 [thread overview]
Message-ID: <20130527080248.GE11166@pengutronix.de> (raw)
In-Reply-To: <CAFSh4UzaOcbD456e408Qw4F=Ynt1WCXwrUx7ekC1GKLZRkFznw@mail.gmail.com>
Hello,
On Tue, May 21, 2013 at 04:20:20PM +0100, Tom Cook wrote:
> On Tue, May 21, 2013 at 12:16 PM, Sebastian Andrzej Siewior
> <bigeasy@linutronix.de> wrote:
> > please CC the list.
>
> Sorry.
>
> >
> > On 05/11/2013 06:43 PM, Tom Cook wrote:
> [snip]
> >
> > 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?
>
> No. I've also tried compiling without kgdb and enabling tracers still
> causes a crash (see below).
>
> Again, I'm far from expert here, but as near as I can tell, a fast
> interrupt exception handler is causing a data abort exception. Do the
> tracers use fast interrupts to wake up? Is there some tracer-related
> memory that's getting swapped out?
>
> pi@raspberrypi:~/rt-tests$ sudo ./cyclictest -p95 -m -f -b 2000
> # /dev/cpu_dma_latency set to 0us
> [ 199.186167] Bad mode in data abort handler detected
> [ 199.186194] Internal error: Oops - bad mode: 0 [#1] PREEMPT ARM
> [ 199.186246] Modules linked in: snd_bcm2835 snd_pcm snd_seq
> snd_timer snd_seq_device snd snd_page_alloc
> [ 199.186260] CPU: 0 Not tainted (3.6.11-rt31+ #1)
> [ 199.186297] PC is at ring_buffer_lock_reserve+0x7c/0x144
> [ 199.186326] LR is at vfs_write+0x140/0x188
> [ 199.186341] pc : [<c009486c>] lr : [<c00efda4>] psr: 600001d1
> [ 199.186341] sp : da645ef8 ip : da645e28 fp : da645f6c
> [ 199.186348] r10: 00000000 r9 : 00000000 r8 : 00000008
> [ 199.186357] r7 : 200001d1 r6 : c030226c r5 : c012cd64 r4 : c0732000
> [ 199.186366] r3 : 200001d1 r2 : 00000018 r1 : 00000000 r0 : db801420
> [ 199.186375] Flags: nZCv IRQs off FIQs off Mode FIQ_32 ISA ARM
What are you using fiqs for? AFAIK they are not well supported in
mainline Linux even.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2013-05-27 8:02 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
2013-05-21 15:20 ` Tom Cook
2013-05-27 8:02 ` Uwe Kleine-König [this message]
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
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