Re: [PATCH RFC 0/2] assign each vcpu an owning thread and improve yielding

[Paolo Bonzini <pbonzini@redhat.com>]

On 03/12/2014 13:12, David Hildenbrand wrote:
>> This series improves yielding on architectures that cannot disable preemption
>> while entering the guest and makes the creating thread of a VCPU the owning
>> thread and therefore the yield target when yielding to that VCPU.
>>
>> We should focus on the case creating thread == executing thread and therefore
>> remove the complicated handling of PIDs involving synchronize_rcus.
>>
>> This way we can speed up the creation of VCPUs and directly yield to the
>> executing vcpu threads.
>>
>> Please note that - in theory - all VCPU ioctls should be triggered from the same
>> VCPU thread, so changing threads is not a scenario we should optimize.
>>
>>
>> David Hildenbrand (2):
>>   KVM: don't check for PF_VCPU when yielding
>>   KVM: thread creating a vcpu is the owner of that vcpu
>>
>>  include/linux/kvm_host.h |  1 +
>>  virt/kvm/kvm_main.c      | 22 ++--------------------
>>  2 files changed, 3 insertions(+), 20 deletions(-)
>>
> 
> Hi Paolo,
> 
> would be good if you could have a look at these patches.

Sure.

I think patch 1 is fine and I am applying it.  For patch 2, what about
moving the ->pid assignment in the KVM_RUN case of kvm_vcpu_ioctl?

Paolo