Igor Delovski Board

[XNote]

The Free Lunch Is Over: A Fundamental Turn Toward Concurrency in Software


"The major processor manufacturers and architectures, from Intel and
AMD to Sparc and PowerPC, have run out of room with most of their
traditional approaches to boosting CPU performance. Instead of driving
clock speeds and straight-line instruction throughput ever higher, they are
instead turning en masse to hyperthreading and multicore architectures."

"And that puts us at a fundamental turning point in software development,
at least for the next few years and for applications targeting general-purpose
desktop computers and low-end servers."

[Core123]

"Before Vista is even out of the gates, a Microsoft exec was talking
Wednesday about Windows' replacement at a VC conference. Speaking at
The Venture Forum conference, Microsoft's Bryan Barnett, a program
manager for external research programs in the Microsoft Research group,
said multicore architectures are of particular interest when weighing what to
put in future operating systems at the company. "Taking full advantage of
the processing power that those multicore architectures potentially make
available requires operating systems and development tools that don't exist
largely today," Barnett said. Well, with Vista in the pipeline as long as it has
been, you must admit it is not surprising Microsoft is taking the long-term
view. And it won't be built overnight: There is no timetable for a Windows
successor right now. But early work on this effort has not yet been
organized, with five or six small projects afoot in various places throughout
the company, Barnett said."

On Slashdot: Microsoft Ponders Windows Successor

[Ike]

Common questions about Computer Processors

"This article isn't meant to be an in-depth review of any particular
processor technologies, but rather a quick examination of the common
issues and questions that seem to arise when considering and comparing
modern processors. As such, the article will gloss over technical details
and arguements about a technology in favour of explaining overall
concepts."

[delovski]

The Problem with Threads

"For concurrent programming to become mainstream, we must discard
threads as a programming model. Nondeterminism should be judiciously
and carefully introduced where needed, and it should be explicit in
programs."

"Nondeterminism should be explicitly added to programs, and only
where needed, as it is in sequential programming. Threads take the
opposite approach. They make programs absurdly nondeterministic and
rely on programming style to constrain that nondeterminism to achieve
deterministic aims."

[XNote]

Thinking Parallel Blog,
by Michael Suess

"I have been doing parallel programming since about 2002, mostly in
C / C++ using OpenMP, POSIX Threads and MPI. I have also evaluated
and tried some other parallel programming systems (e.g. Java threads,
Cilk, BSP, Perl Threads, Erlang) and will continue to do so in the future to
broaden my view (and because I am always eager to explore new
things). Since I have been doing this fulltime as a part of my work at the
Programming Languages / -Methodologies research group at the
University of Kassel, I have gained a lot of experience in the field,
especially with my favourite parallel programming system, OpenMP and
C/C++."

[XNote]

Intel pledges 80 cores in five years

"Intel's prototype uses 80 floating-point cores, each running at 3.16GHz,
Justin Rattner, Intel's chief technology officer, said in a speech following
Otellini's address. In order to move data in between individual cores and
into memory, the company plans to use an on-chip interconnect fabric
and stacked SRAM (static RAM) chips attached directly to the bottom of
the chip, he said."

[delovski]

Raymond Chen: Does a dual-core processor count as one or two for licensing purposes?

"..., Windows XP Home supports one processor, but you if your one processor
is a dual-core processor, then it will use both cores."

[delovski]

IBM cranks dual-core Power6 up to 5GHz

"IBM plans to crank up the speed on its Power6 server chip to 5.0GHz, far
higher than competing processors from Intel and Sun.

Despite its high frequency, the chip will avoid overheating through its small,
65-nanometer process geometry, high-bandwidth buses running as fast as
75G bytes per second, and voltage thresholds as low as 0.8 volts, IBM said."

[delovski]

MSDN Magazine: Reap the Benefits of Multithreading without All the Work

Kang Su Gatlin & Pete Isensee: Among those in the parallel computation
field, a common joke is "Parallel computing is the wave of the future…and
always will be." This little joke has held true for decades. A similar sentiment
was felt in the computer architecture community, where an end of
processor clock speed growth seemed always on the horizon, but the
clocks kept getting faster. The multicore revolution is the collision of this
parallel community optimism and architecture community pessimism."

[delovski]

Digg: The Trouble with Multi-Core Computers

"Today's top-of-the-line computers have dual-core processors, by next
year, major chip makers Intel and AMD will have rolled out quad-core
systems. Although multiple processors are theoretically faster than a
single core, writing software that takes advantage of many processors--a
task called parallel programming--is extremely difficult."

[delovski]

JoS: your take on shrink wrap software and the new quad core CPUs?

"I definitely don't think that your average application should be trying to
handle multiple processors, though if there is stuff going on that will block
the UI, it should certainly be multithreaded."

[Ike]

Digg: Intel introduces new quad-core chips

"For better or for worse, today's official launch of the Core 2 Quad Q6600
puts us well into the quad-core era. Not even Hennessy and Patterson,
much less the coders at the world's largest software company, can think
of enough ways to keep all four cores busy, but here we are
nonetheless..."

[Ike]

Slashdot: An Overview of Parallelism

... a recently released report from Berkeley entitled "The Landscape of
Parallel Computing Research: A View from Berkeley:

"Generally they conclude that the 'evolutionary approach to parallel hardware
and software may work from 2- or 8-processor systems, but is likely to
face diminishing returns as 16 and 32 processor systems are realized,
just as returns fell with greater instruction-level parallelism.' This assumes
things stay 'evolutionary' and that programming stays more or less how it
has done in previous years (though languages like Erlang can probably
help to change this)."

[Ike]

Slashdot: Is Parallel Programming Just Too Hard?

"There has been a lot of talk recently about the need for programmers to
shift paradigms and begin building more parallel applications and systems.
The need to do this and the hardware and systems to support it have been
around for a while, but we haven't seen a lot of progress. The article says
that gaming systems have made progress, but MMOGs are typically years
late and I'll bet part of the problem is trying to be more parallel/distributed.

Since this discussion has been going on for over three decades with little
progress in terms of widespread change, one has to ask: is parallel programming
just too difficult for most programmers? Are the tools inadequate or perhaps
is it that it is very difficult to think about parallel systems? Maybe it is a
fundamental human limit. Will we really see progress in the next 10 years
that matches the progress of the silicon?"

[delovski]

JoS: ressources (introduction/books) about parallel programming?

"Can someone here give me links to books, introductions, webcasts and
other net ressources about parallel programming, please?"

[Ike]

anyone using more threading to work with multiple cores?

"Since clock speed seems at least temporarily to be topped out. Curious if
anyone coding video games is using more threading also."

[delovski]

WIRED: Why You're Not Getting Your Money's Worth Out of That New CPU

"But multicore CPU architectures are creating a nightmare for programmers,
particularly those who want to take full advantage of the new chips' power.
The upshot? Much of your brand-new CPU's potential, like an uneducated brain,
is going to waste."

[Ike]

JoS: Amdahl vs Moore or, why multicores won't save your bloated app

"So how does that change the way desktop applications are written and
marketed? Will developers go back to squeezing bits out of structs and
instructions out of loops? Will new approaches to concurrency take
hold? Will applications become smaller and more focused? Is software
bloat dead?"

[delovski]

Slashdot: Multitasking Considered Detrimental

"In one of the many letters he wrote to his son in the 1740s, Lord
Chesterfield offered the following advice: 'There is time enough for
everything in the course of the day, if you do but one thing at once,
but there is not time enough in the year, if you will do two things at
a time.'

To Chesterfield, singular focus was not merely a practical way to
structure one's time; it was a mark of intelligence... E-mails pouring
in, cell phones ringing, televisions blaring, podcasts streaming--all
this may become background noise, like the 'din of a foundry or
factory' that [William] James observed workers could scarcely avoid
at first, but which eventually became just another part of their daily
routine.

For the younger generation of multitaskers, the great electronic din
is an expected part of everyday life. And given what neuroscience
and anecdotal evidence have shown us, this state of constant intentio-
nal self-distraction could well be of profound detriment to individual
and cultural well-being."

[delovski]

reddit - Cloud kills database by Robert X. Cringely

"We're entering the age of cloud computing, remember? And clouds, it turns
out, don't like databases, at least not as they have traditionally been used."

[delovski]

reddit.com - An Overview of Apples Grand Central Dispatch

"What makes this stuff cool is that it's shifted the abstraction away from
threads. The new abstraction is a queue, which is a lightweight list of work
(blocks) to be processed serially (with respect to other work on the list).
What makes this really cool is that it is easy and very fast for one queue to
make work for another."

[delovski]

forums.macrumors.com - Grand Central

"I am very interested in any info regarding the new Grand Central technolo-
gy, especially how it can be used as an application programmer."

Slashdot: Apple Open Sources Grand Central Dispatch

"Apple has open sourced libdispatch, also known as Grand Central Dispatch,
which is technology in Snow Leopard that makes it easier for developers to
take advantage of multi-core parallelism. Kernel support is not required,
but performance optimizations Apple made for supporting GCD are visible in
xnu. Block support in C is required and is currently available in LLVM (note
that Apple has submitted their implementation of C blocks for standardiza-
tion)."

[delovski]

Slashdot - Research Suggests Brain Has a 2-Task Limit for Multi-
tasking

"The brain is set up to manage two tasks, but not more, a new study sug-
gests. That's because, when faced with two tasks, a part of the brain known
as the medial prefrontal cortex (MFC) divides so that half of the region
focuses on one task and the other half on the other task. This division of
labor allows a person to keep track of two tasks pretty readily, but if you
throw in a third, things get a bit muddled.

'What really the results show is that we can readily divide tasking. We can
cook, and at the same time talk on the phone, and switch back and forth
between these two activities,' said study researcher Etienne Koechlin of
the Université Pierre et Marie Curie in Paris, France. 'However, we cannot
multitask with more than two tasks.'"