Linked by Thom Holwerda on Fri 25th Sep 2009 23:12 UTC, submitted by Still Lynn
Microsoft Most of us are probably aware of Singularity, a research operating system out of Microsoft Research which explored a number of new ideas, which is available as open source software. Singularity isn't the only research OS out of Microsoft; they recently released the first snapshot of a new operating system, called Barrelfish. It introduces the concept of the multikernel, which treats a multicore system as a network of independent cores, using ideas from distributed systems.
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RE[3]: Comment by kaiwai
by Mike Pavone on Sat 26th Sep 2009 15:04 UTC in reply to "RE[2]: Comment by kaiwai"
Mike Pavone
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But then they explain they have made the "OS structure hardware-neutral" in 3.2.

So in other words: Let's use message passing since it is fast on our AMD development machine, but if it is too slow on the next gen hardware, we will switch to something else.

Not exactly solving the problem, IMHO.

That's not really an actual portrayal of what they said.

Their basic conclusion is that as the number of cores increases, the cost of cache-coherency will increase such that updates that span multiple-cache lines will be slower than passing a message to each core and letting the update occur locally. There's no real way around this problem so assuming that core counts continue to increase using a message passing approach like they took here, will make sense (it already does on large machines, there doesn't seem to be much of an advantage on 4 core machines).

What is architecture specific is the most efficient message passing method. From what I gathered from the paper, a lot of this is handled by the system knowledge base, but even if a future piece of hardware requires a fundamentally different message passing mechanism (like the addition of a dedicated inter-core messaging) it won't require a fundamental change in the organization of the OS.

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