Hi I tried to run a Linux Kernel with Preempt RT patch on a QEMU emulated machine using TCG (ARM guest, x86_64 guest).
I expected the guest to have high latencies, but more or less constant. But I found, using cyclictest, a lot of randomness and a lot of difference between the average and the maximum latency. I thought this may be due to I/O overhead. The current system has a root filesystem through NFS, and I'm launching the tests through a serial terminal and saving the results in files. But the high priority thread saves the result in memory, it is the low priority thread that saves it in files. Is this an expected behaviour? I can't see why. I'd like to know if there is a certain reason why it doesn't work. Or if it should work and the problem is too much I/O overhead. Or any other hint to understand it. Thanks Marc
