Re: [Bugfix] x86, irq: Fix a regression caused by commit b5dc8e6c21e7

From: Alex Deucher
Date: Thu Aug 13 2015 - 15:46:19 EST

On Mon, Aug 10, 2015 at 9:06 PM, Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> wrote:
> On 2015/8/10 23:00, Alex Deucher wrote:
>> On Sun, Aug 9, 2015 at 4:15 AM, Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> wrote:
>>> Alex Deucher, Mark Rustad and Alexander Holler reported a regression
>>> with the latest v4.2-rc4 kernel, which breaks some SATA controllers.
>>> With multi-MSI capable SATA controllers, only the first port works,
>>> all other ports times out when executing SATA commands. This regression
>>> bisects to 52f518a3a7c2 ("x86/MSI: Use hierarchical irqdomains to manage
>>> MSI interrupts"), but it's not the root cause, it just triggers a bug
>>> caused by b5dc8e6c21e7 ("x86/irq: Use hierarchical irqdomain to manage
>>> CPU interrupt vectors").
>>>
>>> With this patch applied, the affected SATA controllers work as expected.
>>
>> Yes, this fixes the SATA regression:
>> Tested-by: Alex Deucher <alexander.deucher@xxxxxxx>
>>
>> I'm not sure if it's related to this patch or not (I haven't bisected
>> it independently yet), but MSIs don't seem to work on GPUs. See the
>> line for amdgpu. This is just after loading the driver.
> Hi Alex,
> This patch only affects multiple-MSI, and it seems that your
> gpu only uses one MSI interrupt, so it may not be related to this patch.
> And this seems like a sort of interrupt storm.
>> 52: 16579895 16579562 16580988 16583443 IR-PCI-MSI
>> 524288-edge amdgpu
>
> Does it make any change by disable interrupt remapping?

Nope. Still going crazy:
46: 4769660 4769130 4775899 4784657 PCI-MSI
524288-edge amdgpu


> Does it make any change by disable MSI?

If I set pci=nomsi, the sata controllers time out. If I disable MSIs
just for the gpu, I don't get any interrupts:
25: 0 0 0 0 IR-IO-APIC
0-fasteoi amdgpu

Alex

> Thanks!
> Gerry
>
>>
>> $ cat /proc/interrupts
>> CPU0 CPU1 CPU2 CPU3
>> 0: 138 0 0 0 IR-IO-APIC
>> 2-edge timer
>> 1: 2 2 1 4 IR-IO-APIC
>> 1-edge i8042
>> 7: 1 0 0 0 IR-IO-APIC 7-edge
>> 8: 0 0 1 0 IR-IO-APIC
>> 8-edge rtc0
>> 9: 0 0 0 0 IR-IO-APIC
>> 9-fasteoi acpi
>> 14: 0 0 0 0 IR-IO-APIC
>> 14-edge pata_atiixp
>> 15: 0 0 0 0 IR-IO-APIC
>> 15-edge pata_atiixp
>> 16: 302 303 301 314 IR-IO-APIC
>> 16-fasteoi snd_hda_intel
>> 17: 0 0 0 0 IR-IO-APIC
>> 17-fasteoi ehci_hcd:usb7, ehci_hcd:usb8
>> 18: 0 0 0 0 IR-IO-APIC
>> 18-fasteoi ohci_hcd:usb9, ohci_hcd:usb10, ohci_hcd:usb11
>> 24: 0 0 0 1 PCI-MSI 4096-edge
>> AMD-Vi
>> 26: 0 0 0 0 IR-PCI-MSI
>> 34816-edge PCIe PME
>> 27: 0 0 0 0 IR-PCI-MSI
>> 344064-edge PCIe PME
>> 28: 0 0 0 0 IR-PCI-MSI
>> 348160-edge PCIe PME
>> 29: 0 0 0 0 IR-PCI-MSI
>> 350208-edge PCIe PME
>> 30: 247 255 1381 4617 IR-PCI-MSI
>> 278528-edge ahci0
>> 31: 162 163 164 181 IR-PCI-MSI
>> 278529-edge ahci1
>> 34: 2 1 2 17 IR-PCI-MSI
>> 262144-edge xhci_hcd
>> 35: 0 0 0 0 IR-PCI-MSI
>> 262145-edge xhci_hcd
>> 36: 0 0 0 0 IR-PCI-MSI
>> 262146-edge xhci_hcd
>> 37: 0 0 0 0 IR-PCI-MSI
>> 262147-edge xhci_hcd
>> 38: 0 0 0 0 IR-PCI-MSI
>> 262148-edge xhci_hcd
>> 39: 0 0 0 0 IR-PCI-MSI
>> 264192-edge xhci_hcd
>> 40: 0 0 0 0 IR-PCI-MSI
>> 264193-edge xhci_hcd
>> 41: 0 0 0 0 IR-PCI-MSI
>> 264194-edge xhci_hcd
>> 42: 0 0 0 0 IR-PCI-MSI
>> 264195-edge xhci_hcd
>> 43: 0 0 0 0 IR-PCI-MSI
>> 264196-edge xhci_hcd
>> 44: 0 0 0 0 IR-PCI-MSI
>> 2097152-edge xhci_hcd
>> 45: 0 0 0 0 IR-PCI-MSI
>> 2097153-edge xhci_hcd
>> 46: 0 0 0 0 IR-PCI-MSI
>> 2097154-edge xhci_hcd
>> 47: 0 0 0 0 IR-PCI-MSI
>> 2097155-edge xhci_hcd
>> 48: 0 0 0 0 IR-PCI-MSI
>> 2097156-edge xhci_hcd
>> 50: 40 41 41 40 IR-PCI-MSI
>> 526336-edge snd_hda_intel
>> 51: 14 15 21 1105 IR-PCI-MSI
>> 2621440-edge em1
>> 52: 16579895 16579562 16580988 16583443 IR-PCI-MSI
>> 524288-edge amdgpu
>> NMI: 4 3 4 3 Non-maskable interrupts
>> LOC: 15020 10425 8933 8584 Local timer interrupts
>> SPU: 0 0 0 0 Spurious interrupts
>> PMI: 4 3 4 3 Performance
>> monitoring interrupts
>> IWI: 1 1 1 1 IRQ work interrupts
>> RTR: 0 0 0 0 APIC ICR read retries
>> RES: 7203 5501 10621 5077 Rescheduling interrupts
>> CAL: 498 559 614 591 Function call interrupts
>> TLB: 58 149 104 95 TLB shootdowns
>> TRM: 0 0 0 0 Thermal event interrupts
>> THR: 0 0 0 0 Threshold APIC interrupts
>> DFR: 0 0 0 0 Deferred Error
>> APIC interrupts
>> MCE: 0 0 0 0 Machine check exceptions
>> MCP: 1 1 1 1 Machine check polls
>> HYP: 0 0 0 0 Hypervisor
>> callback interrupts
>> ERR: 1
>> MIS: 0
>> PIN: 0 0 0 0 Posted-interrupt
>> notification event
>> PIW: 0 0 0 0 Posted-interrupt
>> wakeup event
>>
>> This worked fine on 4.1. Any ideas?
>>
>> Thanks,
>>
>> Alex
>>
>>
>>>
>>> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
>>> Reported-by: Alex Deucher <alexdeucher@xxxxxxxxx>
>>> Reported-by: Mark Rustad <mrustad@xxxxxxxxx>
>>> Reported-by: Alexander Holler <holler@xxxxxxxxxxxxx>
>>> ---
>>> Hi Alex, Mark and Alexandler,
>>> Sorry for the long delay to root cause this regression, it's
>>> really annoying. Could you please help test this patch against the
>>> latest v4.2-rcx?
>>> Thanks!
>>> Gerry
>>> ---
>>> arch/x86/kernel/apic/vector.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
>>> index f813261d9740..2683f36e4e0a 100644
>>> --- a/arch/x86/kernel/apic/vector.c
>>> +++ b/arch/x86/kernel/apic/vector.c
>>> @@ -322,7 +322,7 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
>>> irq_data->chip = &lapic_controller;
>>> irq_data->chip_data = data;
>>> irq_data->hwirq = virq + i;
>>> - err = assign_irq_vector_policy(virq, irq_data->node, data,
>>> + err = assign_irq_vector_policy(virq + i, irq_data->node, data,
>>> info);
>>> if (err)
>>> goto error;
>>> --
>>> 1.7.10.4
>>>
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