Re: [GIT pull] x86 APIC updates for 4.15

From: Thomas Gleixner
Date: Thu Nov 30 2017 - 17:47:40 EST


On Thu, 30 Nov 2017, Maarten Lankhorst wrote:
> Op 30-11-17 om 10:18 schreef Thomas Gleixner:
> # cat /sys/kernel/debug/irq/irqs/28
> handler: handle_edge_irq
> device: 0000:00:02.0
> status: 0x00000000
> istate: 0x00000000
> ddepth: 0
> wdepth: 0
> dstate: 0x01401200
> IRQD_ACTIVATED
> IRQD_IRQ_STARTED
> IRQD_SINGLE_TARGET
> IRQD_AFFINITY_SET
> node: 0
> affinity: 4
> effectiv: 4
> pending:
> domain: PCI-MSI-2
> hwirq: 0x8000
> chip: PCI-MSI
> flags: 0x10
> IRQCHIP_SKIP_SET_WAKE
> parent:
> domain: VECTOR
> hwirq: 0x1c
> chip: APIC
> flags: 0x0

Ok. Fine. At that point the interrupt is assigned to CPU4

> # cat /sys/kernel/debug/irq/irqs/28
> handler: handle_edge_irq
> device: 0000:00:02.0
> status: 0x00000400
> _IRQ_NOPROBE
> istate: 0x00000000
> ddepth: 0
> wdepth: 0
> dstate: 0x01401300
> IRQD_ACTIVATED
> IRQD_IRQ_STARTED
> IRQD_SINGLE_TARGET
> IRQD_AFFINITY_SET
> IRQD_SETAFFINITY_PENDING
> node: 0
> affinity: 0,5-7
> effectiv: 0
> pending: 4
> domain: PCI-MSI-2
> hwirq: 0x8000
> chip: PCI-MSI
> flags: 0x10
> IRQCHIP_SKIP_SET_WAKE
> parent:
> domain: VECTOR
> hwirq: 0x1c
> chip: APIC
> flags: 0x0

Now after suspend/resume it's affine to CPU 0 and a request to move it back
to CPU4 is pending.

That looks halfways sane, but:

> affinity: 0,5-7
> effectiv: 0
> pending: 4

does not make sense because 4 is not in 0,5-7

Can you please enable the tracepoints:

/sys/kernel/debug/tracing/events/irq_vectors/vector*

and

/sys/kernel/debug/tracing/events/irq_matrix/*

and collect the trace from

/sys/kernel/debug/trace

right after resume or maybe after the timeout hit.

That might not give us all required info, but at least it will allow me to
come up with the necessary extras required. Right now I'm tapping in the
dark

Thanks,

tglx