Messages in this thread | | | Date | Sun, 30 Aug 2015 21:15:56 +0800 | From | Hanjun Guo <> | Subject | Re: [PATCH] arm64: fix a migrating irq bug when hotplug cpu |
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On 08/30/2015 02:12 AM, Marc Zyngier wrote: > On 2015-08-29 16:12, Jiang Liu wrote: >> On 2015/8/29 21:00, Yang Yingliang wrote: >>> From: Yang Yingliang <yangyingliang@huawei.com> >>> >>> When cpu is disabled, all irqs will be migratged to another cpu. >>> In some cases, a new affinity is different, it needed to be coppied >>> to irq's affinity. But if the type of irq is LPI, it's affinity will >>> not be coppied because of irq_set_affinity's return value. >>> So copy the affinity, when the return value is IRQ_SET_MASK_OK_DONE. >> Hi Yingliang, >> If irq_set_affinity callback returns IRQ_SET_MASK_OK_DONE, >> it means that irq_set_affinity has copied the new CPU mask to irq >> affinity mask. It would be better to change irq_set_affinity for LPI >> to follow this rule. > > The main issue here seems to be that we do not call irq_set_affinity, but > that we directly call into the top-level irqchip method, which relies on > the core code to do the copy (see irq_do_set_affinity). Too bad. > > It feels like the arm/arm64 code would probably be better consolidated into > kernel/irq/migration.c, which already deals with some of this for x86 > and ia64. It would save us the duplication and will make sure we don't > miss things next time we add a new return code, as irq_do_set_affinity > would handle this properly. > > Thoughts?
I agree. In arch/arm64/kernel/irq.c the irq migrate code is the same as ARM32, and it's duplicate. But this is a bugfix, can we fix it in a simple way, and refactor the code later?
Thanks Hanjun
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