From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <512B77AF.9020509@control.lth.se> Date: Mon, 25 Feb 2013 15:39:43 +0100 From: Anders Blomdell MIME-Version: 1.0 References: <511E5112.9030006@control.lth.se> <511E53A5.1030406@siemens.com> <512B3A5F.5000707@control.lth.se> <512B58B1.4060509@xenomai.org> In-Reply-To: <512B58B1.4060509@xenomai.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] kernel BUG at arch/x86/kernel/ipipe.c:589! on motherboard DX79SI List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: Jan Kiszka , Xenomai 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); goto out: } } else { /* Software-generated. */ irq = vector; flags = IPIPE_IRQF_NOACK; } ... out: return 1; Regards Anders -- Anders Blomdell Email: anders.blomdell@control.lth.se Department of Automatic Control Lund University Phone: +46 46 222 4625 P.O. Box 118 Fax: +46 46 138118 SE-221 00 Lund, Sweden