New Mechanism for Fast System Calls

TL;DR

This paper introduces the fastcall space, a new layer in OS architecture that enables ultra-fast system calls by significantly reducing transition times, balancing performance and control.

Contribution

The paper proposes the fastcall space, a novel OS layer that accelerates system calls by approximately 15 times while preserving OS control over hardware access.

Findings

Fastcall space reduces system call transition time by ~15x.

Maintains OS control while achieving high performance.

Enables microsecond-scale system call execution.

Abstract

System calls have no place on the fast path of microsecond-scale systems. However, kernel bypass prevents the OS from controlling and supervising access to the hardware. In this paper we introduce the fastcall space, a new layer in the traditional OS architecture, that hosts fastcalls. A fastcall implements the fast path of a traditional kernel operation and can stay on the fast path, because the transition to the fastcall space is $\approx\times 15$ faster than to the kernel space. This way the OS does not give up the control over device access, whereas the applications maintain their performance.