In a multiple core system there are multiple scheduler to schedule the Erlang processes. one scheduler is mapped with one CPU. My doubt is: Erlang Virtual machine is also a process running on some kernel thread. then to which to CPU it got mapped? or it share all CPUs according to the availability. (OS provide the CPU time according to the availability)?
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An Erlang Virtual Machine runs as a single OS process. Within that process, it runs multiple threads, one per scheduler (and possibly additional threads for asynchronous I/O etc.). By default, you get one scheduler thread per CPU core.
Erlang processes ("green threads") are executed by the scheduler threads, which do load balancing between them, so there could be a hundred thousand Erlang processes being executed by 4 scheduler threads (on a quad-core machine) within a single operating system process. Normally, the OS does the mapping of scheduler threads onto physical cores, but see also How, if at all, do Erlang Processes map to Kernel Threads?.
