Messages in this thread | | | Date | Fri, 3 May 2013 11:43:23 +0100 | From | Stefano Stabellini <> | Subject | Re: [Xen-devel] [PATCH 1/3] arm_arch_timer: introduce arch_timer_stolen_ticks |
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On Thu, 2 May 2013, Christopher Covington wrote: > > So the virtual timer should appear to have been running even while time > > is being stolen and therefore stolen time needs to be accounted via some > > other means. > > Something that's not currently obvious to me is that given that the stolen > cycle accounting should be done, what makes the architected timer interrupt > handler the ideal place to do it?
That is a good question and I would appreciate suggestions to improve the patch.
Given that Xen x86 and ia64 does stolen time accounting from the timer interrupt handler:
arch/x86/xen/time.c:xen_timer_interrupt arch/ia64/kernel/time.c:timer_interrupt
and given that the arch_timer is the only timer used by Xen on ARM and that it includes a virt_timer that is made on purpose to be used by virtual machines, I thought that it might be a good place for it.
I also thought that doing it this way, KVM should be able to reuse the same hook.
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