Comment by arp242 | Hacker News Reader

Comment by arp242 | Hacker News Reader

I guess it's faster with sudo because the regular account has some resource limits, or something? Didn't mention which system is being used (Linux? macOS? Something else?) but I can't repro on my Linux system, where performance is identical:

  % cargo run --release
  [..]
  Parsing speed: 103761177.00 Bytes/s
  Parsing speed: 103.76 MB/s
  Parsing speed: 0.10 GB/s

  % doas cargo run --release
  [..]
  Parsing speed: 105401032.21 Bytes/s
  Parsing speed: 105.40 MB/s
  Parsing speed: 0.11 GB/

Wild guess, but different versions of Rust for the users?

Too fast of a compile time, different versions would recompile the whole dep tree. And even just the end code would take more than .02s

One run is not statistically significant %) Try running 10 times each, throw away the fastest and the slowest, indicate the average and min/max among the remaining runs.

Any random background processes might slow the system slightly during the initial run. A slightly better state of the page cache on the second run could play a role, too. Flushing the FS cache before each run might be a good idea; doing cat file.json > /dev/null could be an equally good idea.

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