On 2013-02-25 15:54, Jan Kiszka wrote:
On 2013-02-25 15:39, Anders Blomdell wrote:
On 2013-02-25 13:27, Gilles Chanteperdrix wrote:
On 02/25/2013 11:18 AM, Anders Blomdell wrote:
On 2013-02-15 16:26, Jan Kiszka wrote:
On 2013-02-15 16:15, Anders Blomdell wrote:
Hi,
I have a DX79SI that dies with "kernel BUG at
arch/x86/kernel/ipipe.c:589!" when running Xenomai. This is not very
surprising since when running the system with an ordinary kernel thera
are a few 'do_IRQ: X.Y No irq handler for vector (irq -1)' each day.
Question is if it would be possible to do something less fatal than
'BUG_ON(irq < 0);' in the code below:
This remains a bug that has to be understood.
int __ipipe_handle_irq(struct pt_regs *regs)
{
struct ipipe_percpu_data *p = __ipipe_this_cpu_ptr(&ipipe_percpu);
int irq, vector = regs->orig_ax, flags = 0;
struct pt_regs *tick_regs;
if (likely(vector < 0)) {
irq = __this_cpu_read(vector_irq[~vector]);
BUG_ON(irq < 0);
} else { /* Software-generated. */
irq = vector;
flags = IPIPE_IRQF_NOACK;
}
Kernel 3.5.7 with latest I-pipe?
Yes.
This is the second report of this kind,
see [1] for the discussion and suggestions. If you don't have KGDB and
that kind enabled, try Gilles' instrumentations.
After a running xenomai five and a half day on a DX58SO motherboard, the
system crashed, leaving a single 'do_IRQ: 2.166 No irq handler for
vector (irq -1)' on our logserver.
I'm planning to put in Gilles instrumentations and change the BUG_ON to
a WARN_ON/WARN, but what should I return after that (my guess is a
'return 1', but waiting a week to be proved wrong would be a waste of
time :-).
Returning 1 is incorrect:
- you should probably jump to the end of the __ipipe_handle_irq function
- if the irq is irq 7, meaning a spurious irq, Linux should handle it,
so, __ipipe_dispatch_irq should be called.
OK, so you mean that I'm probably lokking at two different problems
DX58SO: a spurious interrupt (irq==7) passes through __ipipe_handle_irq
without triggering BUG_ON, but something else breaks.
DX79SI: some (spurious?) interrupt results in irq < 0, triggering BUG_ON
Would the following changes be what you have in mind:
if (likely(vector < 0)) {
irq = __this_cpu_read(vector_irq[~vector]);
if (irq < 0) {
WARN(irq < 0, "irq(%d) < 0", irq);
Again, that's only an instrumentation to help finding the bug.
I know (have to crawl before i can walk :-))
My understanding of the code is that if irq < 0, should not call
__ipipe_dispatch_irq, since its irq argument is unsigned, but perhaps
the MAYDAY and IPIPE_STALL_FLAG stuff should be executed (moving the
out: label up a few lines).
I guess that I don't need to consider the special case when
p->hrtimer_irq == -1 and irq == -1?
According to my reading of the code, Linux should behave incorrectly
> over invalid vector_irq entries as well.
The difference on DX79SI being that Linux (3.6.11) only logs do_IRQ,
while Xenomai (Linux 3.5.7/xenomai-2.6.2.1) gives a BUG_ON which makes
all filesystems read-only, and after that everything more or less
freezes :-(
Jan
goto out:
}
} else { /* Software-generated. */
irq = vector;
flags = IPIPE_IRQF_NOACK;
}
...
out:
return 1;
Regards
Anders
--
Anders Blomdell Email: [email protected]
Department of Automatic Control
Lund University Phone: +46 46 222 4625
P.O. Box 118 Fax: +46 46 138118
SE-221 00 Lund, Sweden
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