Linked by Thom Holwerda on Sun 16th Apr 2006 15:36 UTC
Right in between a car crash and Easter, I knew I had to write a Sunday Eve Column. So here I am, digesting vast quantities of chocolate eggs (and I don't even like chocolate), craving for coffee (for me about as special as breathing), with the goal of explaining to you my, well, obsession with microkernels. Why do I like them? Why do I think the microkernel paradigm is superior to the monolithic one? Read on.
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RE[2]: Why should there be kernels anyway?
by Cloudy on Mon 17th Apr 2006 20:29
in reply to "RE: Why should there be kernels anyway?"
Member since:2006-02-15
The trick is to use systems on which the transition between protection domains is assisted by the VM hardware rather than hindered. The PA-RISC VM model, for example, makes transitions between memory protection domains very fast, nearly as fast as procedure calls that don't transition.
This is what hardware designers and OS designers keep missing. The VM system should make accessability and addressability of memory distinct so as implementation of protection domains in this way is cheap.
We at HP tried to convince Intel to do this in Itanium, but I didn't stick around long enough to see if it made it.
News
Linked by Thom Holwerda on 05/18/13 21:06 UTC
"At the end of a week in which Electronic Arts confirmed it wasn't developing a thing for the Wii U, one of the software engineers in EA Sports' Canada studio, in a series of since-deleted tweets, disparaged the console as 'crap' and suggested Nintendo should give up on hardware altogether. 'The Wii U is crap. Less powerful than an Xbox 360. Poor online/store. Weird tablet', tweeted Bob Summerwill, listed as a senior software engineer at EA Canada, in a reply to a tweet posting a link about EA's no-Wii U news. 'Nintendo are walking dead at this point'." The Wii U is turning into the 21st century's Virtual Boy.
Linked by Thom Holwerda on 05/18/13 7:37 UTC
"In NixOS, the entire operating system - the kernel, applications, system packages, configuration files, and so on - is built by the Nix package manager from a description in a purely functional build language. The fact that it's purely functional essentially means that building a new configuration cannot overwrite previous configurations. Most of the other features follow from this." Interesting approach. A Linux distribution, sure, but with some very refreshing ideas about system configuration.
Linked by fran on 05/18/13 1:38 UTC
Google added, among other features, C/C++ support to its new version of AIDE. From Android-IDE, "Now you can write parts of your app or your whole app in C/C++ on your device. AIDE supports the Standard Android NDK toolchain (GCC 4.6 + Bionic, STL, ...). No changes are necessary if you want to build an app developed on a PC with Eclipse. C/C++ development is fully integrated: Build errors appear in the error list and files can easily be navigated to with Go to file. The editor supports C/C++ syntax highlighting."
Linked by Thom Holwerda on 05/17/13 23:35 UTC, submitted by kragil
Ars nails it: "The answer is that Google did announce what amounts to a fairly substantial Android update yesterday. They simply did it without adding to the update fragmentation problems that continue to plague the platform. By focusing on these changes and not the apparently-waiting-in-the-wings update to the core software, Google is showing us one of the ways in which it's trying to fix the update problem."
Linked by MOS6510 on 05/17/13 22:22 UTC
"It is good for programmers to understand what goes on inside a processor. The CPU is at the heart of our career. What goes on inside the CPU? How long does it take for one instruction to run? What does it mean when a new CPU has a 12-stage pipeline, or 18-stage pipeline, or even a 'deep' 31-stage pipeline? Programs generally treat the CPU as a black box. Instructions go into the box in order, instructions come out of the box in order, and some processing magic happens inside. As a programmer, it is useful to learn what happens inside the box. This is especially true if you will be working on tasks like program optimization. If you don't know what is going on inside the CPU, how can you optimize for it? This article is about what goes on inside the x86 processor's deep pipeline."
Linked by Thom Holwerda on 05/17/13 22:15 UTC, submitted by Tom
"It was the only moment I heard regret slip into Otellini's voice during the several hours of conversations I had with him. 'The lesson I took away from that was, while we like to speak with data around here, so many times in my career I've ended up making decisions with my gut, and I should have followed my gut,' he said. 'My gut told me to say yes.'" The world would've been a much different place - Apple would have been less dependant on Samsung for its chips, which probably would've meant less money for Samsung to develop its Galaxy business.
Linked by Thom Holwerda on 05/16/13 21:41 UTC
Glass is getting some love at Google I/O as well. New applications have been released - Facebook, Twitter, Evernote, Elle, Tumblr, and CNN. Perhaps more interesting: the newly announced Google Glass Developer Kit will allow offline applications and direct hardware access - great for hacking and expanding Glass' potential. This kit will really allow hackers to put Glass through its paces.
Linked by Thom Holwerda on 05/16/13 17:04 UTC
"But Beck and Merrill decided that simply banning toxic players wasn't an acceptable solution for their game. Riot Games began experimenting with more constructive modes of player management through a formal player behavior initiative that actually conducts controlled experiments on its player base to see what helps reduce bad behavior. The results of that initiative have been shared at a lecture at the Massachusetts Institute of Technology and on panels at the Penny Arcade Expo East and the Game Developers Conference." Absolutely fascinating stuff. I'm a League of Legends player, and to be honest, the community isn't nearly as bad as some make it out to be. I'm happy Riot games has the guts to employ science to address the issue.
Linked by Thom Holwerda on 05/16/13 13:17 UTC
"Android and iOS, the number one and number two ranked smartphone operating systems worldwide, combined for 92.3% of all smartphone shipments during the first quarter of 2013 as Windows Phone crept past BlackBerry for 3rd place. According to the International Data Corporation Worldwide Quarterly Mobile Phone Tracker, Android smartphone vendors and Apple shipped a total of 199.5 million units worldwide during 1Q13, up 59.1% from the 125.4 million units shipped during 1Q12." Windows Phone doubles from a few to twice few, iOS loser market share as its growth is slower than that of the overall market. BlackBerry continues slide into irrelevance.
Linked by Thom Holwerda on 05/16/13 12:06 UTC
"According to the latest research from our Wireless Smartphone Strategies service, global Android smartphone profits reached US$5 billion in total during the first quarter of 2013. Samsung dominated and captured an impressive 95 percent share of all Android smartphone profits." Wow.More News »
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Member since:
2005-11-16
I think the above could be achieved with a solution called 'memory map'. Just like a process has a page map, a software component should also have a memory map, i.e. a range of addresses that it is allowed to access.
Accessing RAM is slow, but accessing several levels of the paging structures and severel levels of "memory map" structures and the final physical RAM location (every time the CPU accesses RAM) would be unbearable. That's why CPUs cache the paging structures (TLB), and that's why they'd need to cache the "memory map structures". If you're going to change the "memory map" structures every time the CPU changes between software components then you'll lose the benefits of this caching and end up with "memory map structure cache" misses.
You might aswell just change the paging structures instead (which is what micro-kernels do)...