A new kernel timer API [LWN.net]

A new kernel timer API

Posted May 19, 2005 22:24 UTC (Thu) by kleptog (subscriber, #1183)
In reply to: A new kernel timer API by brouhaha
Parent article: A new kernel timer API

LOL! If we're making devices which are smaller than a third of a millimetre across, I imagine we'd get a much better return clustering a few thousand onto a single chip than we'd get by trying to make them all run at a terahertz clock rate.

My personal feeling is that measuring less than a nanosecond is not useful given than the moment you're accessing something off-chip (like say memory) you're going to be delayed by tens of thousands of picoseconds and memory latency is not reducing anywhere near as fast as clock speeds.

But hey, I'm willing to be proved wrong.

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A new kernel timer API

Posted May 22, 2005 15:17 UTC (Sun) by haraldt (guest, #961) [Link]

Processors are asyncronous even today, aren't they?
Todays standard is to move information from place A to place B within a manageable number of clock ticks. If a clock tick takes a picosecond, then the only requirement is that places A and B are never more than one third of a millimeter apart.

Instructions may have to run through a lot of clock ticks this way, but it's all a matter of resolution.

Won't promise this is is going to happen, but hey, it's an idea?

A new kernel timer API

Posted May 22, 2005 15:39 UTC (Sun) by haraldt (guest, #961) [Link]

Err.. that A and B are in multiples of a third millimeter apart.

You'd probably need asynchronous buses, asyncronous memory devices etc. too.
The distance between processor and main memory, for example, could be a load of clock ticks, often with several signals travelling on the same wire. But as long as equipment can handle asyncronous signalling (in addition to the speed of course) it's far from impossible.