On 09/27/2012 05:02 PM, Christian Borntraeger wrote:
> On 20/09/12 07:22, Michael S. Tsirkin wrote:
>> On Thu, Sep 20, 2012 at 08:16:08AM +0800, Fengguang Wu wrote:
>>> Hi Michael,
>>>
>>> FYI, there are new compile warnings show up in
>>>
>>> tree: git://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
>>> head: 879238fecc051d95037ae76332916209a7770709
>>> commit: 9fc77441e5e1bf80b794cc546d2243ee9f4afb75 [41/42] KVM: make processes waiting on vcpu mutex killable
>>> config: s390-defconfig
>>>
>>> All error/warnings:
>>>
>>> arch/s390/kvm/interrupt.c: In function 'kvm_s390_handle_wait':
>>> arch/s390/kvm/interrupt.c:428:12: warning: ignoring return value of 'vcpu_load', declared with attribute warn_unused_result [-Wunused-result]
>>>
>>> vim +428 arch/s390/kvm/interrupt.c
>>> 418 add_wait_queue(&vcpu->arch.local_int.wq, &wait);
>>> 419 while (list_empty(&vcpu->arch.local_int.list) &&
>>> 420 list_empty(&vcpu->arch.local_int.float_int->list) &&
>>> 421 (!vcpu->arch.local_int.timer_due) &&
>>> 422 !signal_pending(current)) {
>>> 423 set_current_state(TASK_INTERRUPTIBLE);
>>> 424 spin_unlock_bh(&vcpu->arch.local_int.lock);
>>> 425 spin_unlock(&vcpu->arch.local_int.float_int->lock);
>>> 426 vcpu_put(vcpu);
>>> 427 schedule();
>>> > 428 vcpu_load(vcpu);
>>> 429 spin_lock(&vcpu->arch.local_int.float_int->lock);
>>> 430 spin_lock_bh(&vcpu->arch.local_int.lock);
>
> IIRC schedule will do vcpu put/load anyway via the preempt notifiers. So the right fix
> is probably to just remove the vcpu_put/load around that schedule.
> Will double check and send a patch.
Yes, this is correct. On a preemptible kernel this happens all the time.
--
error compiling committee.c: too many arguments to function
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