Messages in this thread | | | Date | Tue, 23 Feb 2010 23:23:37 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [patch] x86: kvm: Convert i8254/i8259 locks to raw_spinlocks |
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On Tue, 23 Feb 2010, Jan Kiszka wrote:
> Thomas Gleixner wrote: > > The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert > > them to raw_spinlock. No change for !RT kernels. > > Doesn't fly for -rt anymore: pic_irq_update runs under this raw lock and > calls kvm_vcpu_kick which tries to wake_up some thread -> scheduling > while atomic.
Hmm, a wakeup itself is fine. Is that code waking a wake queue ?
> This used to work up to 956f97cf. -rt for 2.6.31 is not yet affected, > but 2.6.33 should be broken (haven't checked, using kvm-kmod over 2.6.31 > ATM). I can provide a patch that restores the deferred kicking if it's > acceptable for upstream.
Well, at least is would be nice to have one for -rt.
Thanks,
tglx
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