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| author | Ben Gamari <bgamari.foss@gmail.com> | 2016-08-30 17:05:25 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2016-08-31 13:15:33 -0400 |
| commit | 28b71c55d057b780d92b351498ec611287dedbd4 (patch) | |
| tree | 2520c49879a934df43085d508de0e968ea06797b /docs/users_guide/using-concurrent.rst | |
| parent | 2ee1db60ab29258fa9f8ab820f778bd0bb7f87a4 (diff) | |
| download | haskell-28b71c55d057b780d92b351498ec611287dedbd4.tar.gz | |
users_guide: More capabilities than processors considered harmful
Test Plan: None.
Reviewers: austin, simonmar
Reviewed By: simonmar
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2487
Diffstat (limited to 'docs/users_guide/using-concurrent.rst')
| -rw-r--r-- | docs/users_guide/using-concurrent.rst | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/docs/users_guide/using-concurrent.rst b/docs/users_guide/using-concurrent.rst index 8c0587c7ad..d62b811345 100644 --- a/docs/users_guide/using-concurrent.rst +++ b/docs/users_guide/using-concurrent.rst @@ -136,7 +136,8 @@ RTS ``-N`` options. Be careful when using all the processors in your machine: if some of your processors are in use by other programs, this can actually harm - performance rather than improve it. + performance rather than improve it. Asking GHC to create more capabilities + than you have physical threads is almost always a bad idea. Setting ``-N`` also has the effect of enabling the parallel garbage collector (see :ref:`rts-options-gc`). |