>>950631
>You're right, we don't deserve this shitter who doesn't understand the shit he preaches. Remember when segmented memory was his favourite thing of the month?
Segmented memory is still a good thing but not because it's my favorite. It's good because of the reduction in code complexity and memory usage. UNIX weenies hate whenever someone brings up actual numbers like speed and RAM usage.
>He screeched regularly over how much better modern operating systems would be with this crucial innovation, only for another anon to read the paper he was pushing.
The way Multics does it is after the "instead" in this paragraph, not before. He probably confused the old way other OSes do it with the way Multics does it.
http://multicians.org/multics-vm.html
>The fundamental advantage of direct addressability is that information copying is no longer mandatory. Since all instructions and data items in the system are processor-addressable, duplication of procedures and data is unnecessary. This means, for example, that core images of programs need not be prepared by loading and binding together copies of procedures before execution; instead, the original procedures may be used directly in a computation. Also, partial copies of data files need not be read, via requests to an I/O system, into core buffers for subsequent use and then returned, by means of another I/O request, to their original locations; instead the central processor executing a computation can directly address just those required data items in the original version of the file. This kind of access to information promises a very attractive reduction in program complexity for the programmer.
>Turns out that not only did unixhater completely misunderstand the concept, he didn't even realize that Unix had the same shit for ages.
These Multics innovations were ignored by UNIX. There are a few attempts at making UNIX more like Multics, but they're still hindered by the flat memory space of the "abstract" PDP-11 C runs on.
http://multicians.org/multics-vm.html
>The absolute core location of the beginning of a segment and its length are also attributes interpreted by the hardware at each reference, allowing the segment to be relocated any where in core and to grow and shrink independently of other segments.
https://arxiv.org/pdf/1105.1811.pdf
An allocated memory block can be very quickly extended or
shrunk without having to copy memory – a feature which is very
useful for the common operation of extending large arrays and
which is also provided by the proprietary mremap() function
under Linux. Kimpe et al. [31] researched the performance
benefits of a vector class based upon this feature and found a 50-
200% memory usage overhead when using a traditional vector
class over a MMU-aware vector class as well as extension
time complexity becoming dependent on the elements being
added rather than the size of the existing vector. While the
test employed was synthetic, a 50% improvement in execution
time was also observed thanks to being able to avoid memory
copying.
What will they copy from real OSes next? UNIX weenies are even saying hardware memory tagging is good now. 60s, 70s, and 80s commercially available technology is 2018 "research" for UNIX weenies.
https://arxiv.org/ftp/arxiv/papers/1802/1802.09517.pdf
Memory tagging will not eliminate all memory safety bugs; however, our analysis indicates that
memory tagging, when widely supported by hardware, will help significantly reduce the number
of such bugs and is likely to complicate exploitation of the few remaining ones.
>As the saying goes, those who don't understand Unix are doomed to reinvent it badly.
UNIX was made because "Those who don't understand Multics are doomed to reinvent it badly." Lisp machines and VME were made by people who understood Multics, not superficial parts like the name "ls" and the "-" argument syntax, but the structure of the OS and what the parts do. The only time someone reinvented UNIX badly was Plan 9.
"It's State of the Art!" "But it doesn't work!" "That IS
the State of the Art!"
Alternatively: "If it worked, it wouldn't be research!"
The only problem is, outside of the demented heads of the
Unix weenies, Unix is neither State of the Art nor research!