Usage of /dev/random slowing down jobs

ROOT
1

I have a set of ROOT macros to process TTrees and fill histograms (TH1D). Lately I observed that the jobs I send to my local institute’s cluster stall or work very slowly. I was told that usage of /dev/random might affect this as the strange slow-down only occurs on the nodes where multiple instances of my code run.

I have several questions on searching a solution of my issue:

  • Can compiling my code help (not using macros directly)?
  • How to reduce the use of /dev/random?

Note: I’m not using any random numbers. I’m talking about core ROOT code that utilises /dev/random.

2

If I recall /dev/random is used in a feature of the interpreter that prevent dereference of bad pointers.

Indeed, compiling your code (even just via ACliC) should solve the problem.

Cheers,
Philippe.

3

Thank you for prompt reply. I will try compiling my code and report back the results.

4

I compiled my code (executable, not ACliC) and I still see /dev/random in the process file descriptors. Is this expected but it will not be used?

5

Yes, it is still setup and ready to be used if/when the interpreter is invoked.

6

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