On 14.02.2018 12:51, Paolo Bonzini wrote: > On 13/02/2018 18:08, David Hildenbrand wrote: >> On 13.02.2018 18:02, David Hildenbrand wrote: >>> On 13.02.2018 17:44, Paolo Bonzini wrote: >>>> On 13/02/2018 17:26, Christian Borntraeger wrote: >>>>>> The test takes fairly long, especially because we only have 128MB of ram >>>>>> and allocate 3 times in a row ~100mb of virtual memory. >>>>> >>>>> Does it make sense to change the memory size in the unittests.cfg file? e.g. via extra_params? >>>> >>>> The test takes 5 seconds on x86 KVM and about a minute on TCG (lots of >>>> TLB misses). Maybe it's an s390-specific bug in the test? >>> >>> Under TCG: 1m 6,823s >>> >>> I have to idea how long it takes under LPAR. Right now, I only have a >>> z/VM based system available, so we are already using nested >>> virtualization (implemented by z/VM). I expect things to be slow :) >>> >>> Will try to find a LPAR to test with ... >>> >> >> LPAR: 0m 6.552s >> z/VM: > 6m >> >> So I don't think its a BUG. It's really nested virtualization kicking in. > > Whoa. How does KVM-on-KVM-on-LPAR fare? We do a lot of IPTE calls, which flush the TLB on all CPUs. But I think this could also be because the z/VM machine I am running on is simply overloaded. But of course also because our nested virt implementation in KVM is better ;) Just tried nested under KVM (KVM-on-KVM-on-LPAR): real 0m 9.411s > > I'll change the comment to > > # can take fairly long when KVM is nested inside z/VM > > Thanks, > > Paolo > -- Thanks, David / dhildenb
