Re: [Xen-devel] cpuidle and un-eoid interrupts at the local apic

["Thimo E." <abc@xxxxxxxxxx>]

Ah, sorry.  Output is attached.

Am 08.09.2013 11:53, schrieb Andrew Cooper:
> On 08/09/2013 00:37, Thimo E. wrote:
> > Hello Andrew,
> >
> > ok, thanks. This is what I assumed.
> >
> > The output of "xl debug-keys iMQ" is empty.
> Sorry - I should have been more clear.  `xl debug-keys` dumps its
> information into the xen dmesg buffer, so `xl dmesg` will capture the
> results.
>
> ~Andrew
>
> > [root@localhost ~]#  dmesg |grep arcmsr
> > [    8.159321] arcmsr 0000:01:00.0: PCI INT A -> GSI 16 (level, low)
> > -> IRQ 16
> > [    8.159413] arcmsr 0000:01:00.0: setting latency timer to 64
> > [    8.170316] arcmsr 0000:01:00.0: get owner: 7ff0
> > [    8.170414] arcmsr 0000:01:00.0: irq 1276 (276) for MSI/MSI-X
> > [    8.170421] IRQ 1276/arcmsr: IRQF_DISABLED is not guaranteed on
> > shared IRQs
> > [    8.170654] arcmsr0: msi enabled
> >
> > [root@localhost /]# cat /proc/irq/1276/spurious
> > count 61007
> > unhandled 8
> > last_unhandled 36736990 ms
> >
> > arcmsr is the driver of the Areca Storage Raid Controller. Used it
> > already before with Xenserver 6.0.2 for years, no problems.
> >
> > THe messages "IRQF_DISABLED is not guaranteed...." and "8 unhandled
> > interrupts" look interesting. I am not a kernel hacker but what I
> > interpret from
> > http://lxr.free-electrons.com/source/kernel/irq/manage.c?v=2.6.32:
> >
> > 1025         if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) ==
> > 1026 (IRQF_SHARED|IRQF_DISABLED)) {
> > 1027                 pr_warning(
> > 1028                   "IRQ %d/%s: IRQF_DISABLED is not guaranteed on
> > shared IRQs\n",
> > 1029                         irq, devname);
> > ...
> > 738                  * Force MSI interrupts to run with interrupts
> > 739                  * disabled. The multi vector cards can cause stack
> > 740                  * overflows due to nested interrupts when enough of
> > 741                  * them are directed to a core and fire at the same
> > 742                  * time.
> > 743                  */
> > 744                 if (desc->msi_desc)
> > 745                         new->flags |= IRQF_DISABLED;
> >
> > --> "IRQF_DISABLED is not guaranteed on shared IRQs" warning is only
> > printed when irqflags IRQF_SHARED and IRQF_DISABLED are set
> > --> Is that what we see in the kernel oops the stack overflow the
> > comment in lines 738-742 is talking about ?!
> > --> IRQF_SHARED is set, so MSI interrupt 1276 is shared ?! I thought
> > that it is not possible that MSI interrupts are shared. Attached
> > you'll see my /proc/interrupts
> >
> > So what I do now is disabling MSI for the arcmsr driver. Could this be
> > the source of the problem ?! But why is 1276 shared ?!
> >
> > Best regards
> >    Thimo
> >
> > Am 07.09.2013 19:02, schrieb Andrew Cooper:
> > > irq 29 is just an internal Xen number for accounting all interrupts.  It
> > > doesn't mean anything specific regarding hardware etc.  The vector and
> > > affinity would expect to change as dom0s vcpus are moved around by the
> > > scheduler.
> > >
> > > domain-list=0 means that this interrupt is targeted at dom0 (It is a
> > > list because certain interrupts have to be shared my more than 1
> > > domain).  Helpfully, the keyhandler truncates the pirq field, so 276 is
> > > unlikely to be correct.  As it is a dom0 MSI, I am guessing it actually
> > > matches up with interrupt 1276 in /proc/interrupts, if there is one.
> > >
> > > Can you provide the results of `xl debug-keys iMQ`, and attach
> > > /proc/interrupts to this email (just in case the setup has changed after
> > > playing with your BIOS)
> > >
> > > ~Andrew

Attachment: xl_debus_keys20130908.txt
Description: Text document

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