On 8 Apr 2015 at 0:57, Bjørn Roald wrote:
Shooting from the hip here, why not require at least 2G of free RAM to start a task running in parallel. 2G may seem excessively defensive, but it provide good margins and who around here have dev. boxes with less than 8G RAM these days.
That would be an unhelpful heuristic on VMs with balloon allocated memory.
OK, so if I understand that correctly, in such an environment the reported available RAM would be low, but as contention is detected by the balloon driver the guest RAM would be inflated, thus more RAM demanding processes would fit just fine. That is a tricky one.
I believe for OpenVZ and BSD jail containers this is exactly the case, and most of my personal use of ./b2 is from within such a container either through Jenkins or a throw away dev environment. For KVM with balloon page allocating drivers I actually don't know what the OS reports as free memory, and you think I would know given how many of those VMs I run (what can I say, it "just works"). I'll check when I get back from vacation. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/