Messages in this thread | | | Date | Fri, 17 Oct 2014 09:29:50 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH v3 3/4] irq: Allow multiple clients to register for irq affinity notification |
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On Fri, 10 Oct 2014, Lina Iyer wrote: > On Wed, Oct 08 2014 at 09:03 -0600, Thomas Gleixner wrote: > > On Thu, 25 Sep 2014, Lina Iyer wrote: > > > > How would a general "keep track of the targets of all interrupts in > > > > the system" mechanism make use of this? > > > Sorry, I do not understand your question. > > > PM QoS is only interested in the IRQs specified in the QoS request. If > > > there are no requests that need to be associated with an IRQ, then PM > > > QoS will not register for an affinity change notification. > > > > Right, and I really hate the whole per irq notifier. It's a rats nest > > of life time issues and other problems. > > > > It also does not tell you whether an irq is disabled, reenabled or > > removed, which will change the qos constraints as well unless you > > plaster all drivers with updates to qos for those cases. > > > > So what about adding a qos field to irq_data itself, have a function > > to update it and let the irq core keep track of the per cpu irq > > relevant qos constraints and provide an evaluation function or a > > notifier for the PM/idle code? > > If that isnt intrusive in the IRQ core, then we can make it work for PM > QoS. The issue that I am concerned is that, it might result in back and > forth between IRQ and PM QoS frameworks. If that doesnt happen, then we > are good with this approach.
I can't tell that upfront, but I think it's worth to explore it.
Thanks,
tglx
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