Understanding the rationale behind dropping of "block devices"

[Poul-Henning Kamp]

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In message <a86ad6f5-954d-62f0-fdb3-9480a13dc1c3 at freebsd.org>, Julian Elischer 
writes:

>Having said that, it would be trivial to add a 'caching' geom layer to 
>the system but that has never been needed.

A tinker-toy-cache like that would be architecturally disgusting.

The right solution would be to enable mmap(2)'ing of disk(-like)
devices, leveraging the VM systems exsting code for caching and
optimistic prefetch/clustering, including the very primitive
cache-control/visibility offered by madvise(2), mincore(2), mprotect(2),
msync(2) etc.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.