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Comment by cbsmith

9 years ago

I'm pretty sure that even at their slowest, syscalls aren't going to match IO overhead. It's not like the mkfile is CPU bound.

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cbsmith

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mpweiher  9 years ago

The point of the article is that I was also "pretty sure" about exactly that, and advances in hardware performance meant I was wrong...

2GB/s is pretty damn fast, 0.5 nanoseconds per byte.

  • cbsmith  9 years ago

    That's not what the article showed. It showed that synchronous IO latency was the limiting factor. By arranging your IOs into little 512-byte chunks, you don't make it terribly easy for the filesystem to efficiently use the underlying device --not surprising, given that it doesn't even want to work in 512 byte sectors, and operates more efficiently with lots of a parallel io operations.