From: Philippe Gerum <rpm@xenomai.org>
To: Pavel Machek <pma@domain.hid>
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] kernel oopses when killing realtime task
Date: Thu, 07 Oct 2010 16:07:37 +0200 [thread overview]
Message-ID: <1286460457.13186.35.camel@domain.hid> (raw)
In-Reply-To: <20101007115728.GA24500@domain.hid>
On Thu, 2010-10-07 at 13:57 +0200, Pavel Machek wrote:
> Hi!
>
> I have... quite an interesting setup here.
>
> SMP machine, with special PCI card; that card has GPIOs and serial
> ports. Unfortunately, there's only one interrupt, shared between
> serials and GPIO pins, and serials are way too complex to be handled
> by realtime layer.
>
[snip]
>
> Unregistration is:
> my_context->ready = 0;
> rtdm_irq_disable(&my_context->irq_handle);
>
>
> Unfortunately, when the userspace app is ran and killed repeatedly (so
> that interrupt is registered/unregistered all the time), I get
> oopses in __ipipe_dispatch_wired() -- it seems to call into the NULL
> pointer.
rtdm_irq_disable() will only mask the IRQ in the PIC, not unregister the
handler from the pipeline core. In case your handler is pulled out from
the kernel as part of a module, this may explain this behavior.
rtdm_irq_free() is something you likely look after.
>
> I decided that "wired" interrupt when the source is shared between
> Linux and Xenomai, is wrong thing, so I disable "wired" interrupts
> altogether, but that only moved oops to __virq_end.
>
"wired" just means "deliver to topmost domain unconditionally", this is
a way to optimize the IRQ delivery path to the real-time handler,
without going through the entire domain propagation logic. As you
already found out, this is not related to registration issues.
> I'm using 2.6.27.21-ELinOS-46 with xenomai-2.4.7 . Problem does go
> away if I boot with maxcpus=1.
>
> Any ideas? (Besides using non-historic kernel; but that's
> unfortunately not exactly easy here.)
The I-pipe code for x86 had a number of fixes since 2.6.27, including
rather serious ones. At the very least, I would recommend to check
whether this one is in your tree:
http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=80a79bb5b0e74d75fa4a511d7b9a08a015e37f46
This may decrease worst case latency in SMP quite significantly under
load.
>
> Pavel
>
>
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
--
Philippe.
prev parent reply other threads:[~2010-10-07 14:07 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-07 11:57 [Xenomai-help] kernel oopses when killing realtime task Pavel Machek
2010-10-07 12:11 ` Gilles Chanteperdrix
2010-10-07 13:00 ` Gilles Chanteperdrix
2010-10-07 12:32 ` Jan Kiszka
2010-10-08 7:01 ` Pavel Machek
2010-10-08 7:20 ` Gilles Chanteperdrix
2010-10-08 8:17 ` Philippe Gerum
2010-10-08 8:41 ` Jan Kiszka
2010-10-08 8:57 ` Philippe Gerum
2010-10-08 9:00 ` Philippe Gerum
2010-10-08 9:41 ` Philippe Gerum
2010-10-13 9:03 ` Pavel Machek
2010-10-13 9:16 ` Philippe Gerum
2010-10-13 9:26 ` Pavel Machek
2010-10-13 14:52 ` Philippe Gerum
2010-10-25 16:48 ` Philippe Gerum
2010-10-25 18:10 ` Jan Kiszka
2010-10-25 19:08 ` Philippe Gerum
2010-10-25 19:11 ` Philippe Gerum
2010-10-25 19:15 ` Jan Kiszka
2010-10-25 19:20 ` Philippe Gerum
2010-10-25 19:22 ` Jan Kiszka
2010-10-25 21:12 ` Philippe Gerum
2010-10-25 21:22 ` Jan Kiszka
2010-10-25 21:40 ` Philippe Gerum
2010-10-25 21:47 ` Jan Kiszka
2010-10-26 4:43 ` Philippe Gerum
2010-10-26 5:22 ` Jan Kiszka
2010-10-26 19:33 ` Jan Kiszka
2010-10-28 5:17 ` Philippe Gerum
2010-10-28 7:31 ` Jan Kiszka
2010-10-28 7:38 ` Jan Kiszka
2010-10-28 7:46 ` Philippe Gerum
2010-11-07 15:15 ` Philippe Gerum
2010-11-07 16:22 ` Jan Kiszka
2010-11-07 16:55 ` Philippe Gerum
2010-11-07 16:59 ` Philippe Gerum
2010-11-07 17:19 ` Philippe Gerum
2010-11-09 8:01 ` Jan Kiszka
2010-11-09 8:26 ` Philippe Gerum
2010-11-09 8:39 ` Jan Kiszka
2010-11-09 9:36 ` Philippe Gerum
2010-11-09 13:12 ` Jan Kiszka
2010-11-12 8:48 ` Philippe Gerum
2010-11-12 9:14 ` Jan Kiszka
2010-11-12 13:57 ` Philippe Gerum
2010-11-12 14:30 ` Jan Kiszka
2010-11-12 17:42 ` Philippe Gerum
2010-11-12 18:42 ` Jan Kiszka
2010-11-14 21:28 ` Philippe Gerum
2010-10-07 14:07 ` Philippe Gerum [this message]
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