Re: [PATCH] core-count: A new program to count the number of cpu cores

[Pádraig Brady]

Paolo Bonzini wrote:
> 
>>> Some programs, like 'msgmerge' from GNU gettext, already pay
>>> attention to the OMP_NUM_THREADS variable - a convention shared
>>> by all programs that rely on OpenMP. Can you make the 'sort'
>>> program use the same convention?
>>
>> I am not working on the multi-threaded sort, but if somebody asks I can
>> make it read OMP_NUM_THREADS.
>> If is is already used by other GNU programs, then it seems a good idea
>> to use this value when --threads is not specified on the command line.
> 
> I agree.  This also implies that no OMP_NUM_THREADS and no --threads
> _will_ activate threading by default.
> 
> Of course this should only apply if its effect is not externally
> observable; if I have a very small file B and a very large file A, and I
> can get
> 
>     $ md5sum --threads A B
>     abcdabcdabcdabcdabcdabcdabcdabcd B
>     12341234123412341234123412341234 A
> 
> Then the option would be necessary.

Good point Paolo.
I think that's another argument for splitting separate files to different 
threads.

cheers,
Pádraig.