3 ms·
A long time ago, I was surprised to discover that a mainframe always runs at 100% cpu usage. Its OS makes sure that multiple VMs, each of which has a long list
by kamma4434 4y ago
A long time ago, I was surprised to discover that a mainframe always runs at 100% cpu usage. Its OS makes sure that multiple VMs, each of which has a long list of real-time and batch jobs, neatly prioritized, keep it well fed. An interactive user need an answer now, but a clean-up job can literally take weeks to run. When I looked amazed, the operators told me ‘This thing is so expensive- it cannot be wasted’