Re: [coreutils] draft [PATCH] sort: explicit --parallel=N now overrides environment

[Pádraig Brady]

On 11/12/10 09:05, Paul Eggert wrote:
> It seems to me that this code in sort.c:
> 
>       unsigned long int np2 = num_processors (NPROC_CURRENT_OVERRIDABLE);
>       if (!nthreads || nthreads > np2)
>         nthreads = np2;
> 
> is now obsolete.  It was written assuming spin locks, but now that
> we use mutexes, shouldn't we respect an explicit --parallel=N
> flag?  Something like the following, say?   This would let the user
> override the environment in the command line, which is normally what
> people would expect.

Yes I think you're right.
Related to this is the default number chosen,
which might be best to restrict to 8 or so
as there are diminishing returns after that.
Of course we'd need to benchmark again with
all the recent changes to find an appropriate default.
The gcc compile farm has a niagra 32 core (gcc12) and
and a magny-cours 24 core (gcc10) available.

Also I notice Chen has inadvertently been omitted
from THANKS, and that his UCLA email address should
probably be added to .mailmap

cheers,
Pádraig.