If I can offload work to the OS, great! I don't want to manage the virtual memory backing my mmap when the kernel is really good at it. It is not inherently bad

If I can offload work to the OS, great! I don't want to manage the virtual memory backing my mmap when the kernel is really good at it. It is not inherently bad when CPU time is spent in the kernel. The point I'm taking away from this article is that some workloads (probably not mmap) trigger bottlenecks in the kernel, and would benefit if it were possible to replace those kernel components via app library. That said, we do things like this all the time today. For example, I can provide my own memory allocation library instead of depending on the one provided by the operating system. So I'm unconvinced there are many real world bottlenecks without a descent solution available today. I wonder: Is the real point that leveraging custom implementations is hard and we could all benefit from a nice central repository and a reasonable dependency manager?