Clarification On data.table::getDTthreads(verbose = TRUE)

Open
#6,721 5 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
48/100
Issue type
Documentation
Clarity
Mostly clear
Activity status
Stale
Tech stack
r
Domain
documentation

Research direction

Start with the setDTthreads() function documentation and compare it with the getDTthreads(verbose = TRUE) output shown in the issue. Clarify how the default 50 percent relates to logical CPU cores and why R_DATATABLE_NUM_THREADS can remain unset; done when the documentation no longer makes these values appear contradictory.

Written by the indexing model from the issue text.

Description

documentation

Argument definition in setDTthreads() function documentation seems to confuse the statements of getDTthreads(verbose = TRUE:

> data.table::getDTthreads(verbose = TRUE)
  OpenMP version (_OPENMP)       201511
  omp_get_num_procs()            16
  R_DATATABLE_NUM_PROCS_PERCENT  unset (default 50)
  R_DATATABLE_NUM_THREADS                 unset
  R_DATATABLE_THROTTLE                         unset (default 1024)
  omp_get_thread_limit()                                 2147483647
  omp_get_max_threads()                               16
  OMP_THREAD_LIMIT                                 unset
  OMP_NUM_THREADS                               unset
  RestoreAfterFork                                         true
  data.table is using 8 threads with throttle==1024. See ?setDTthreads.
[1] 8

Here, argument "threads" refers to CPU logical cores. As the "percent" default is 50, the value is 8 as stated by next-to-the-last-row in above code. However the env. variable R_DATATABLE_NUM_THREADS is "unset" leading to confusion. This function documentation should be clarified further. Thank you!

Dominant language
R
Stars
3.9k
Forks
1.1k
Avg merge
14h 4m
Merged PRs (30d)
4

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from Rdatatable/data.table

All issues in Rdatatable/data.table

Similar issues

More R issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.