Re: [Qemu-devel] [PATCH 1/2] accel: allows to select the "best" accelerator

[Paolo Bonzini]

On 04/10/2016 16:18, Thomas Huth wrote:
>>> >> Using only tcg has also some disadvantages: For some tests, it's
>>> >> interesting to know whether they also work properly with KVM (e.g.
>>> >> migration tests), and only using tcg by default slows down the "make
>>> >> check" quite a bit - which might become an issue now that we're adding
>>> >> more and more tests.
>> > 
>> > Which tests are you seeing a slow-down for ?
> Well, everything that is using accel=tcg in tests/ could be accelerated.
> For example, the new ipv6/ppc64 unit test is quite slow with TCG:
> 
> sudo QTEST_QEMU_BINARY=ppc64-softmmu/qemu-system-ppc64 time tests/pxe-test
> 
>  48.46user 0.07system 0:48.48elapsed

Could that point to a firmware bug?  10 network-bound seconds for a boot
makes some sense, but 10 CPU-bound seconds don't...

Paolo