Messages in this thread | | | Date | Tue, 9 Aug 2011 14:51:00 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH 2/3] xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports |
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On Tue, Aug 09, 2011 at 05:28:06PM +0200, Olaf Hering wrote: > On Tue, Aug 09, Ian Campbell wrote: > > > On Thu, 2011-08-04 at 17:20 +0100, Olaf Hering wrote: > > > During a kexec boot some virqs such as timer and debugirq were already > > > registered by the old kernel. The hypervisor will return -EEXISTS from > > > the new EVTCHNOP_bind_virq request and the BUG in bind_virq_to_irq() > > > triggers. Catch the -EEXISTS error and loop through all possible ports to find > > > what port belongs to the virq/cpu combo. > > > > Would it be better to proactively just query the status of all event > > channels early on, like you do in find_virq, and setup the irq info > > structures as appropriate? Rather than waiting for an -EEXISTS I mean.
We only create those structures when the IRQ handler is setup. And since this is a new kernel, the irq_get_handler_data(irq) won't be present. > > Now that I read that again more carefully: > No idea if thats possible, I will leave that answer to Jeremy/Konrad.
But we could an optimization. The find_virq does a search every time from 0->NR_EVENTS. Perhaps we can also check the xen_irq_list_head to skip over the event channels we have already created?
Something like this:
bool skip = false; list_for_each_entry(info, &xen_irq_list_head, list) if (info->evtchn == port && info->cpu == cpu) { skip=true; break; } if (skip) continue
.. snip.. and here is the EVTCHNOP_status hypercall.
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