Messages in this thread | | | Date | Fri, 19 Jun 2015 18:15:46 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [-next] !irqd_can_balance() WARNINGs at irq_move_masked_irq() |
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On Sat, 20 Jun 2015, Jiang Liu wrote:
> [...] > >> Something in the kernel (not yet clear what) tries to move the hpet > >> irq 0 by calling irq_set_affinity(). That's an kernel internal > >> interface which does not check whether the NO BALANCE flag is set for > >> the irq. So the call runs and triggers the move from next interrupt > >> machinery which ends up calling irq_move_masked_irq() and that trips > >> over the flag and yells. > >> > >> That's why I changed the WARN to a pr_warn() because we already know > >> the call stack. > >> > >> So the core behaviour is inconsistent. We let the caller of > >> irq_set_affinity() succeed and yell later because we think it's wrong. > >> > >> I'm pretty sure that we must drop the check for NO BALANCE in > >> irq_move_masked_irq() and only check for the per_cpu bit, but at the > >> same time I really want to know where that call to irq_set_affinity(irq0) > >> is coming from. > >> > >> Can you please collect the output of /proc/timer_list for the previous > >> patch and then replace the previous patch with the one below and > >> gather all the data again? > > > > Hi Thomas, > > Maybe it's caused by the hpet driver itself? > > irq_set_affinity() may set the IRQD_SETAFFINITY_PENDING flag, > > thus triggering the warning. > And the usage pattern seems reasonable, the IRQF_NOBALANCING flag > means nobody may change the affinity except myself:)
Right, that's why I removed the restriction. I just wonder why we have not seen that before ...
Thanks,
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