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Comparing Linux and Minix
Comparing Linux and Minix
Posted Feb 5, 2007 21:51 UTC (Mon) by evgeny (subscriber, #774)Parent article: Comparing Linux and Minix
What puzzles me is the totally inferior FP performance of Minix. Why?? Shouldn't it be determined by the FPU alone? Or does Minix emulates FPU? If yes, this might impact other tests as well.
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FP performance
Posted Feb 5, 2007 21:54 UTC (Mon) by corbet (editor, #1) [Link]
My assumption (really just a guess) is that Minix lacks proper support for the FPU, so the compiler is built to emulate all floating-point operations. It seems like a minor detail; it's hard to imagine that the other tests make any significant use of floating-point.
FP performance
Posted Feb 5, 2007 22:06 UTC (Mon) by evgeny (subscriber, #774) [Link]
Well, all results are FP numbers, so at least some FP operations are used in every test. If the FP performance counters are updates inside the loops, this might me essential (since the emulated FP is orders of magnitude slower). It would be interesting to force Linux to use emulated FP and re-run the tests (or run the benchmarks on a 386SX box ;-)).
Comparing Linux and Minix
Posted Feb 5, 2007 22:05 UTC (Mon) by tjc (subscriber, #137) [Link]
What puzzles me is the totally inferior FP performance of Minix. Why?? Shouldn't it be determined by the FPU alone? Or does Minix emulates FPU? If yes, this might impact other tests as well.See second-to-last question:
Comparing Linux and Minix
Posted Feb 5, 2007 22:35 UTC (Mon) by evgeny (subscriber, #774) [Link]
Ah, thanks, indeed. So, apparently, nobody has voted for such a "numbercrunching" feature since then...
Comparing Linux and Minix
Posted Feb 11, 2007 10:00 UTC (Sun) by ebiederm (subscriber, #35028) [Link]
Cute. Minix is slower and it does less work in the context switch path. That is it doesn't save/restore the FPU.