Messages in this thread | | | Date | Tue, 13 Jan 2015 10:49:59 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH 0/2] genirq: Make irqchip flags work with stacked irq domains |
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On 13/01/15 10:41, Thomas Gleixner wrote: > On Fri, 9 Jan 2015, Marc Zyngier wrote: >> Hi Jiang, >> >> On 09/01/15 03:07, Jiang Liu wrote: >>> On 2015/1/9 1:32, Marc Zyngier wrote: >>>> With the landing of stacked irq domains in 3.19, we have ended up in a >>>> situation where we have a stack of IRQ controllers, each with their >>>> set of flags, but the core code is only able to look at the top-most, >>>> which is not very helpful. This small series is trying to fix this. >>>> >>>> The first patch converts all access to desc->irq_data.chip->flags to >>>> using an accessor, without changing anything else. The second patch >>>> adds some logic to combine these flags as we allocate the interrupts, >>>> ultimately storing the resulting set as part of the irq_desc >>>> structure. >>>> >>>> We end-up with a configuration where the flags can either be located >>>> in the irq_chip structure (non stacked case), or in the irq_desc >>>> (stacked case). While this isn't really ideal, this gives at least the >>>> right level of information to the rest of the IRQ framework. >>> Hi Mark, >>> By this way, we need to aggregate irq_chip flags for every >>> irq. How about changing irq_desc_get_chip_flags(struct irq_desc *desc) >>> to irq_desc_check_chip_flags(struct irq_desc *desc, unsigned int flags) >>> which dynamically walks the stacked irqchips? >> >> That was the other option, but I felt that going through the list of >> irqchips was not a very nice idea performance wise. This is used is some >> moderately hot paths (cond_unmask_eoi_irq, for example), and I wondered >> if we wanted to pay this price at runtime... > > We rather do it at setup time.
That was my thought as well. I'll respin the series with Jiang's fix.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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