Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again

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On 02/24/2010 11:54 AM, Jan Kiszka wrote:
Avi Kivity wrote:
On 02/24/2010 11:41 AM, Jan Kiszka wrote:
Thomas Gleixner wrote:

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 ?

Yes, it's a wake queue.

So what's the core issue?  Is the lock_t in the wait_queue a sleeping mutex?
Yep.

I see. Won't we hit the same issue when we call pic functions from atomic context during the guest entry sequence?

--
error compiling committee.c: too many arguments to function

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