On 16/02/2015 16:09, Gerhard Wiesinger wrote:
On 16.02.2015 15:18, Paolo Bonzini wrote:
>
> On 15/02/2015 09:18, Gerhard Wiesinger wrote:
>>
>> Can you grab some random backtraces ("thread apply all bt full") with
>> gdb?
Very low load on the machine, so I guess most will be sleeping and hard
to catch non sleeping ones. See below
This likely means that the 100% threads are not the I/O (event loop)
threads, but the VCPU threads.
>> Kernel (host/guest): 3.18.6-200.fc21.x86_64 #1 SMP
>> qemu-kvm-2.2.0-5.fc21.x86_64
>>
>> Bug 1178975 - endless loop in clock_gettime() on a kvm-based VM
>>
https://bugzilla.redhat.com/show_bug.cgi?id=1178975
>> is fixed (didn't occour with the test program posted at
>>
https://bugzilla.redhat.com/show_bug.cgi?id=1178975#c28 in 30min,
>> happened before reproduceable in 2min, still running)
>>
>> So I guess there is another problem in the kernel with volatile and gcc
>> optimizations (or maybe in qemu-KVM)
> No, this doesn't look like volatile.
But why 100% on 2 cores?
Because you have 2 VCPUs, I guess.
Paolo