Slashdot Mirror
Multicore Requires OS Rework, Windows Expert Says
alphadogg writes "With chip makers continuing to increase the number of cores they include on each new generation of their processors, perhaps it's time to rethink the basic architecture of today's operating systems, suggested Dave Probert, a kernel architect within the Windows core operating systems division at Microsoft. The current approach to harnessing the power of multicore processors is complicated and not entirely successful, he argued. The key may not be in throwing more energy into refining techniques such as parallel programming, but rather rethinking the basic abstractions that make up the operating systems model. Today's computers don't get enough performance out of their multicore chips, Probert said. 'Why should you ever, with all this parallel hardware, ever be waiting for your computer?' he asked. Probert made his presentation at the University of Illinois at Urbana-Champaign's Universal Parallel Computing Research Center."
'Why should you ever, with all this parallel hardware, ever be waiting for your computer?'
Because I/O is always going to be slow.
Sent from my PDP-11
The problem is that most (if not all) peripheral hardware is not parallel in many senses. Hardware in today's computers is serial: You access one device, then another, then another. There are some cases (such as a few good emulators) which use muti-threaded emulation (sound in one thread, graphics in another) but fundamentally the biggest performance kill is the final IRQs that get called to process data. The structure of modern day computers must change to take advantage of multicore systems.
Since when have OS designers optimised their code to milk every cycle from the available CPUs? They haven't, they just wait for hardware to get faster to keep up with the code.
Specialist Mac support for creative pros, Melbourne
Windows explorer sucks. It always just abandons copies after a fail - even if you're moving thousands of files over a network. Yes, you're left wondering which files did/didn't make it. It's actually easier to sometimes copy all the files you want to shift locally, then move the copy, so that you can resume after a fail. It's laughable you have to do this, however.
But it's not a concurrency issue, and neither, really, are the first 2 problems you mention. They're also down to Windows Explorer sucking.
For that matter, since when have software vendors been willing to pay architects/designers/engineers etc to optimise their software to milk every cycle from the available CPUs and provide useful output with the minimum of effort? They don't, they just wait for hardware to get faster to keep up with code.
The only company that I have personally been exposed to that gives half a hoot about efficient performance is Google. It annoys me beyond belief that other companies think it's acceptable to make the user wait for minutes whilst the system recalculates data derived from a large data set, and doing those calculations multiple times just because a binding gets invoked.
Science advances one funeral at a time- Max Planck
I love how Microsoft can come along in 2010 and with a straight face say it's about time they took multiprocessing seriously. Or say it's about time we started putting HTML5 features into our browser. And we're finally going to support the ISO audio video standard from 2002. And by the way, it's about time we let you know that our answer to the 2007 iPhone will be shipping in 2011. And look how great it is that we just got 10% of our platform modernized off the 2001 XP version! And our office suite is just about ready to discover that the World Wide Web exists. It's like they are in a time warp.
I know they have product managers instead of product designers, and so have to crib design from the rest of the industry, necessitating them to be years behind, but on engineering stuff like multiprocessing, you expect them to at least have read the memo from Intel in 2005 about single cores not scaling and how the future was going to be 128 core chips before you know it.
I guess when you recognize that Windows Vista was really Windows 2003 and Windows 7 is really Windows 2005 then it makes some sense. It really is time for them to start taking multiprocessing seriously.
I am so glad I stopped using their products in 1999.