On Mon, Jun 4, 2018 at 8:33 AM, Thomas Gleixner tglx@linutronix.de wrote:

apic_ack_edge() is explicitely for handling interrupt affinity cleanup when interrupt remapping is not available or disable.

Remapped interrupts and also some of the platform specific special interrupts, e.g. UV, invoke ack_APIC_irq() directly.

To address the issue of failing an affinity update with -EBUSY the delayed affinity mechanism can be reused, but ack_APIC_irq() does not handle that. Adding this to ack_APIC_irq() is not possible, because that function is also used for exceptions and directly handled interrupts like IPIs.

Create a new function, which just contains the conditional invocation of irq_move_irq() and the final ack_APIC_irq(). Making the invocation of irq_move_irq() conditional avoids the out of line call if the pending bit is not set.

Reuse the new function in apic_ack_edge().

Preparatory change for the real fix

Fixes: dccfe3147b42 ("x86/vector: Simplify vector move cleanup") Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org

Tested-by: Song Liu songliubraving@fb.com

---

arch/x86/include/asm/apic.h | 2 ++ arch/x86/kernel/apic/vector.c | 10 ++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -436,6 +436,8 @@ static inline void apic_set_eoi_write(vo

#endif /* CONFIG_X86_LOCAL_APIC */

+extern void apic_ack_irq(struct irq_data *data);

static inline void ack_APIC_irq(void) { /* --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -809,11 +809,17 @@ static int apic_retrigger_irq(struct irq return 1; }

+void apic_ack_irq(struct irq_data *irqd) +{

•   if (unlikely(irqd_is_setaffinity_pending(irqd)))
  

•           irq_move_irq(irqd);
  

•   ack_APIC_irq();
  

+}

void apic_ack_edge(struct irq_data *irqd) { irq_complete_move(irqd_cfg(irqd));

•   irq_move_irq(irqd);
  

•   ack_APIC_irq();
  

•   apic_ack_irq(irqd);
  

}

static struct irq_chip lapic_controller = {