system calls - What's the design principle of syscall? -


how linux determine functionality should classified syscall while others can directly implemented in user space?

a system call performed when processing must occur in kernel - meaning requires escalated privileges or access kernel-private resources. typically if can kept in userspace, it's done there. there performance reasons when things moved kernel processing, , therefore require system call perform. facet transition between userspace , kernelspace relatively expensive.


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