Tag: Operating Systems
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Third time lucky?
Last time we met, my PhD supervisor told me to expect to spend a long time making things that didn’t work: it certainly feels like that right now. My current task is to build a logical model of a working memory allocation scheme for a NoC. I started with some Groovy, then realised that was […]
Adrian McMenamin
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Virtual memory and a new operating system
This is going to be one of those blog posts where I attempt to clarify my thoughts by writing them down … which also means I might change my mind as I go along. My problem is this: I have elected to, as part of my PhD, explore the prospect of building a virtual memory […]
Adrian McMenamin
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Graph cartesian products
On the basis that knowing some more about Graph Theory won’t do me any harm when thinking about operating system behaviour, I am reading about that too right now. But I found the book’s explanation of a Graph Cartesian Product rather less than full, so here is my attempt to make it a bit clearer. […]
Adrian McMenamin
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A GUI for Metapost?
I have sort-of abandoned my Apple Air Book for serious work this last week – going back to a 2008/9 Toshiba laptop (another Morgan Computers purchase) running Linux. The Apple is a lovely device to travel with and is beautiful, if extremely expensive, device with which to browse the web, but a decade of conditioning […]
Adrian McMenamin
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The problem with Apple kit (part one?)
Last September I joined a startup, Centreground Political Communications and, like my three fellow employees, have been using Apple equipment more or less since then. It is good quality kit, focused on (typical) user experience: like Windows done right. And, yes, as a Unix/Linux person I also get a bash shell and access to forty […]
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Working on filesystem code
Nearly a decade ago I wrote a crude, but working, filesystem for the Sega Dreamcast VMU on Linux. I then put ported a very simple web server to the Dreamcast and got the whole thing on Slashdot. I never managed to get the thing into mainline – indeed the battering I got last time I […]
Adrian McMenamin
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The cost of soft/minor faults
Here is a complete graph of the memory use and fault count for a run of ls -lia. As you can see there are only soft/minor faults here – as one would expect (this was a machine with a lot of memory), as the C library provides the ls function and it will be loaded […]
Adrian McMenamin
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Counting soft and hard faults
When a running program references a page of memory that is not mapped into its address space the operating system throws a “page fault” – calling some kernel code to ensure that the page is loaded and mapped, or if the address referenced is not legal, that an appropriate error (a seg fault on x86) […]
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Best book on Linux kernel internals
Write an MSc project report means having to read a lot of source code and constantly referring to texts in the hope that they will make things clearer. I have three books on the kernel – there are obviously others, but I think two of these three will be familiar to most kernel hackers – […]
Adrian McMenamin
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In your face, fan bois
There is something very annoying about Apple users: they pay twice as much as the rest of us for stuff and then think that they are the clever and cool ones. How does that work? Well, here’s some bad news for them: their browser is almost certainly broken. If you look at the graphs on […]
Adrian McMenamin
cartesian product ... stuff about computing mostly 