Messages in this thread | | | Date | Wed, 27 Sep 2023 15:53:48 +0800 | From | Wei Gong <> | Subject | Re: [PATCH v2] genirq: avoid long loops in handle_edge_irq |
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O Tue, Sep 26, 2023 at 02:28:21PM +0200, Thomas Gleixner wrote: > On Mon, Sep 25 2023 at 10:51, Wei Gong wrote: > > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c > > index dc94e0bf2c94..6da455e1a692 100644 > > --- a/kernel/irq/chip.c > > +++ b/kernel/irq/chip.c > > @@ -831,7 +831,8 @@ void handle_edge_irq(struct irq_desc *desc) > > handle_irq_event(desc); > > > > } while ((desc->istate & IRQS_PENDING) && > > - !irqd_irq_disabled(&desc->irq_data)); > > + !irqd_irq_disabled(&desc->irq_data) && > > + cpumask_test_cpu(smp_processor_id(), irq_data_get_affinity_mask(&desc->irq_data))); > > Assume affinty mask has CPU0 and CPU1 set and the loop is on CPU0, but > the effective affinity is on CPU1 then how is this going to move the > interrupt?
Loop is on the CPU0 means that the previous effective affinity was on CPU0. When the previous effective affinity is a subset of the new affinity mask, the effective affinity will not be updated. Therefore, I understand that the scenario you mentioned will not occur?
> > Thanks, > > tglx
Thanks,
Wei Gong
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