id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
5896,Three documentations inaccuracies related to concurrency.,MikolajKonarski,simonmar,"1.

The help info below is wrong. The default is the actual number of cores, or something close.

{{{
~/waste/threadscope-sparkgraph-demo75$ ./parlist +RTS -N2 -lg -s -asdfasdf
parlist: unknown RTS option: -asdfasdf
[...]
parlist:   -N<n>     Use <n> processors (default: 1)
}}}

2.

Here:

http://www.haskell.org/ghc/docs/latest/html/users_guide/using-smp.html

the first sentence of the following is wrong and could be just removed.


{{{
There is no means (currently) by which this value may vary after the program has started.

The current value of the -N option is available to the Haskell program via GHC.Conc.getNumCapabilities, and it may be changed while the program is running by calling GHC.Conc.setNumCapabilities. Note: in the current implementation, the -N value may only be increased, not decreased, by calling GHC.Conc.setNumCapabilities.
}}}

3.

Neither here

http://www.haskell.org/ghc/docs/latest/html/users_guide/using-concurrent.html

nor on first page of the docs it refers to:

http://www.haskell.org/ghc/docs/latest/html/libraries/base-4.5.0.0/Control-Concurrent.html

is there any hint about the possibility and advantages of using ""-threaded"" and ""+RTS -N"". It may be misleading to the users that specifically seek an information about any extra flags they need to start using multiple cores or non-blocking FFI calls.

",bug,closed,normal,7.4.2,Documentation,7.4.1,fixed,,,Unknown/Multiple,Unknown/Multiple,Documentation bug,Unknown,,,,