1. A system to provide improved process scalability via kernel-context sharing by multiple user-space processes, the system comprising: one or more computer processors; and a memory containing computer program code that, when executed by operation of the one or more computer processors, performs an operation comprising: receiving a request from a first user-space process to perform an I/O operation within a kernel context, wherein the request specifies a first effective address of a local effective address space distinct to the first user-space process, wherein the first effective address specifies a location in the local effective address space of the kernel context and a first effective segment identifier; remapping the first effective address to a second effective address in a global effective address space shared by the first user-space process and at least a second user-space process and in order to avoid conflicting addresses therebetween, wherein the second effective address specifies a location in the global effective address space of the kernel context and a second effective segment identifier; and upon determining, by a lookup using the second effective segment identifier on a page table and a shared segment table, a virtual address that maps to a virtual address space within the kernel context, translating the virtual address to a physical memory address, whereafter the I/O operation is performed based on the physical memory address, thereby providing improved process scalability via kernel-context sharing by multiple user-space processes including the first and second user-space processes.