On Tue, 25 Mar 2014, Jeremy White wrote: [...]
Francois, do we have (or could we easily create) a mechanism to test that by constraining the number of VMs that run simultaneously?
Currently the way to do so is to send a patch to modify $MaxActiveVMs, and/or $MaxRevertsWhileRunningVMs in testbot/lib/WineTestBot/Config.pm to Alexandre.
However the old VM host had an 8 core CPU and the limits are to run at most 2 VMs at once, and each VM has only 2 cores (except the build VM which had 4). So really there should not have been much contention on the cores (which it seems like should be all that matters for these tests).
The new VM host has only 4 cores (+hyperthreading). We're still only running two VMs at a time but now the build VM only has 2 cores.
We can do a test with $MaxActiveVMs = 1 and $MaxRevertsWhileRunningVMs = 0 but that would really limit performance.