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by danadam 1718 days ago
> I just did a quick benchmark searching for `kthreadd` using grep and ag and it's magnitudes faster than grep.

I'd be careful with that. You may have just tested the awesomeness of linux caches :-)

Yes, it "looks" magnitudes faster:

  ]$ time grep -Rsn "kthreadd"
  ...
  real    0m26.895s
  user    0m3.131s
  sys     0m3.151s

  ]$ time ag "kthreadd"
  ...
  real    0m0.906s
  user    0m1.930s
  sys     0m1.186s

  ]$ time rg "kthreadd"
  ...
  real    0m0.860s
  user    0m1.756s
  sys     0m1.123s
But wait, somehow grep got magnitutes faster too:

  ]$ time grep -Rsn "kthreadd"
  ...
  real    0m2.961s
  user    0m1.979s
  sys     0m0.959s
And we can make both ag and rg slower:

  ]# echo 1 > /proc/sys/vm/drop_caches
  ]$ time ag "kthreadd"
  ...
  real    0m17.761s
  user    0m2.371s
  sys     0m2.728s

  ]# echo 1 > /proc/sys/vm/drop_caches
  ]$ time rg "kthreadd"
  ...
  real    0m19.276s
  user    0m1.859s
  sys     0m3.063s