title: CPUs in multi-core architectures and memory access
body: <p>I wondered how memory access is handled "in general" if ,for example, 2 cores of CPU try to access memory at the same time (over the memory controller)? Actually the same applies when a core and an DMA-enabled IO device try to access in the same way.</p>
  
  <p><a href="https://stackoverflow.com/questions/41913855/on-dma-and-cpu-concurrency">I think</a>, memory controller is smart enough to utilise the address bus and handle those requests concurrently, however I'm not sure what happens when they try to access to same location or when the IO operation monopolises the address bus and there's no room for CPU to move on.   </p>
  
  <p>Thx</p>