title: Shared library usage in different Linux namespaces
body: <p>The Linux namespace can isolate pid, mount poing, network and so on. I use Linux namespace to implement OS-level virtual machine (just like vserver and LXC), but I often run out of memory. I have a question that if I have two processes in different namespaces and they use a same shared library, will the library be loaded once or twice into the physical memory? Besides, what is the underlayer mechanism of library sharing between processes? Is it like the IPC?</p>