Re: Mac OS X build reference?

[Richard Campbell]

If you have two i7s (approx the last six months of apple products, maybe more) 
then you have 4 logical cores due to hyperthreading, and you should use -j4. 
Generally there's not much downside to using a higher -j number than you have 
logical cores, although you will eventually run out of ram (but probably not 
until -j 32 or so, on a machine with 4 gb ram). 

I've never encountered race conditions with make - that would be a problem with 
make, though, not the Octave sources, right?

Campbell

On Feb 18, 2011, at 13:05, Jordi Gutiérrez Hermoso <address@hidden> wrote:

> On 18 February 2011 11:51, fork <address@hidden> wrote:
>> Jordi Gutiérrez Hermoso <jordigh <at> gmail.com> writes:
>> 
>>> Four hours??? Something's wrong. It takes 2 minutes for me.
>>> 
>>> To compile all of Octave? It takes about 30-40 minutes for me. Are you
>>> parallelising the build?
>> 
>> probably not -- I have 2 cores, how do I do that?
> 
> "make -j2"  will run two compilation processes at once (no prize if
> you guess how to run 4 at once), but it can fail subtly due to
> compilation time race conditions. Try again if it does, or remove the
> -j2 for the portion it could be stuck on.
> 
> - Jordi G. H.