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From: Larry McVoy <lm@mcvoy.com>
To: Dan Cross <crossd@gmail.com>
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Subject: [TUHS] Re: Clever code (was Re: Re: Stdin Redirect in Cu History/Alternatives?
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On Thu, Dec 15, 2022 at 09:02:08AM -0500, Dan Cross wrote:
> On Thu, Dec 15, 2022 at 12:38 AM Bakul Shah <bakul@iitbombay.org> wrote:
> > Don't see how unless they put multiple related services in the same
> > address space, which reduces context switching but tends toward a
> > monokernel (& increased coupling). Unless I am misunderstanding you.
> 
> I don't see why two services in a microkernel couldn't arrange to
> share a region of memory and implement bidirectional queues
> between themselves. With an appropriate signalling mechanism,
> you'd still be context switching but avoiding a lot of copying.

My mind went to similar thoughts.  How did QNX manage the page cache?
Did they have mmap?