[TUHS] Re: If forking is bad, how about buffering?

[Andrew Warkentin <andreww591@gmail.com>]

On Mon, May 13, 2024 at 7:42 AM Douglas McIlroy
<douglas.mcilroy@dartmouth.edu> wrote:
>
>
> These precautions are mere fig leaves that conceal important special cases. The underlying evil of buffered IO still lurks. The justification is that it's necessary to match the characteristics of IO devices and to minimize system-call overhead.  The former necessity requires the attention of hardware designers, but the latter is in the hands of programmers. What can be done to mitigate the pain of border-crossing into the kernel? L4 and its ilk have taken a whack. An even more radical approach might flow from the "whitepaper" at www.codevalley.com.
>
QNX copies messages directly between address spaces without any
intermediary buffering, similarly to L4-like kernels. However, some of
its libraries and servers do still use intermediary buffers.